German Obstacles
German Obstacles
r 
Fi 
NOTES  ON  GERMAN  OBSTAOLES 
INTRUDUCTIUN 
PART  I. 
PART  II. 
PART  III. 
PART  IV. 
PART  V. 
FART  VI. 
M. I.  10 
The  War  uffice 
Augus t,  1943, 
0160/2436(M.I.10) 
nistribution  List  E. 
no.  1 
WIRE 
CUNCRETE  &.  BRI CKWlJRK 
S T E : F ~ L 
DITC:IES 
TIMBER 
MI SCELL.AlffiUUS 
Thi s  publi ca tion  is'         SE'OREl1           or,'     comprehensi ve 
naturE;.  This  grading  is  NuT  intendec\.to  prohibi.t    dissemination 
of  this  information  to  those  who  should  know  i.t  and. it  is  hoped  that 
full  advantago  will  be  taken  in  this  respect  provided  the  complete 
docul11tlnt  is  safeguarded. 
            
GERMAl1  UBSTACLES 
PART  I.  WIRE 
1.  Trip  wire. 
DEnASSIFIED 
2.  Apron  types. 
3.  Concer tina. 
4.  nErun"  (French  type) 
5.  Wire  netting. 
6.  Snar0s. 
7.  Knife-rests. 
8.  Wire  in  Coastal  Areas. 
9.  Ala.rm  wire. 
10.  Heavy  gauge  wire. 
11.  Standard  types  of  iron  pickets. 
PART  II.  CuNORETE  AND  BRICKWuRK. 
1.  General 
2.  vla.lls 
3.  Cubes 
4.  Dragons  teeth 
5.  Tetrahedra 
6.  Hedgehogs 
7.  Posts 
8.  Stars 
9.  Erickwork. 
PART  III.  STEEL 
1.  Curves  rail 
2.  De  Cointet  (ElemGnts  C) 
3.             
4.  Tetrahedra 
5.         Stebl  joists. 
PART  IV. 
DLf0U'EE 1 
>   
1.  LJffi ci'ai 
tYPE:S 
2.  Existing  types. 
3.  Tank  traps. 
4.  Inundations. 
PART  V.  TliYlBEB.. 
PART  VI.  MISCELLANEUUS. 
1.  Crowsfeet. 
PLATE 
1. 
Apron 
IN  D E               ' 
fence  in  depth.  ''-J   
" 
2. 
Apron  fenoe  West  Germany. 
n 
3. 
Conoe.:r:tina  fence  on  a  promtlnade. 
ft 
4. 
Knife  rests  on  beaoh. 
II 
5. 
"  " 
West  Germany. 
rr 
" 
6. 
Wire  fence  to  a  works. 
7. 
Two  parallel  fences. 
" 
8. 
Three 
II 
" 
If 
9. 
Rough  wire  on  sea  wall. 
"  10.  'Afire  on  a  promenade. 
2  lOA. 
Wire  on  top  of  sea  wall. 
If  lOB. 
Wire  netting  on  quay. 
n  11. 
Trip-wire  alarm. 
ff  llA. 
Heavy  gauge  wire. 
It  11B, 
Standard  iron  pickets. 
"  12. 
Curved  fact::  wall. 
fI  l2A. 
Straight  face  wall. 
"  13. 
Beaoh  wall  with  rear  ledge. 
It  13A 
" 
"  wi th  round  top. 
n  14. 
Wall  with  skew  and  straight  gaps. 
" 
14A. 
n 
" 
" 
143 .. 
II 
" 
II  rt 
n 
15.  Walls  across  main  highways, 
" 
l5A.  (Fig.  1)        across  town  thoroughfare. 
" 
(Fig.  2)  Reinforcement  in  beach  walls. 
t1  15]  - D         in  OHERBvURG. 
If 
16.  Dragons  teeth. 
1/ 
17. 
II  II 
II 
18. 
" 
" 
19. 
"  " 
DECLA:SSlfrfO  20.  Brick  wall. 
" 
" 
PLATE  21.  ) 
,  oj,  -         
t                                rai 1  obstacle. 
.  "...,  4'   .,  
w.. 7-   )     .,. 
ft. ...  ',       ) 
) 
IT  24.) 
ff 
25. 
n 
26.  ) 
) 
rr 
27.  ) 
fI 
28.  ) 
) 
" 
29.  ) 
" 
30. 
It 
31. 
" 
32. 
" 
33. 
If 
34. 
n 
35. 
tI 
36. 
n 
37. 
fI 
38. 
" 
39. 
11 
40. 
Constructional  details  of  curved  rail  obstacle 
De  Cointet  obstacle. 
Construction  details  of  De  Cointet  obstacle. 
Steel  Hedgehogs. 
II 
To trahedra. 
R.S.J.  (vertical)  obstacle. 
ufficial  German  ditto. 
R.S.J.  (inclined)  obstacle. 
" 
" 
If 
ST.  MALu  A.  Tk.  ditch. 
Road  block  in  timber. 
ufficial  German  timber  picket  obstacle. 
Steel  "Crowsfoot" 
" 
WIRE. 
1.  TRIP  WlrtE. 
The'  German  name  for  this  obstacle  is  Stolperdrahthindernis.  I!1--
structions  given  in  German  manuals  are  as  follows:- These  obstacles 
should  be     least  30  ft.  in  depth.  They  consist  of  irregular  rows  of 
wooden  pickets,  2  ft.  long  x  3  in.  diam.,  and  plain  or  barbed  wire 
          at  a  height  of  4  - 8  in.  between  pickets.  The  interval  betweeL 
pi cke ts  in  rows  should  be  10  - 13  ft    and  in ter1Tal  between  rows  7  - 1(;  fT,. 
The  freshly  cut  heads  of  pickets  should  be  painted  to  tone  wi th  the  sur 
r
i 
OUlIJ.dings.  RUB    wire  should  be  used  if possible  and  the  obs tacle  may 
nc  ude  snares  (see  para  5). 
Trip  wires  are  frequently  laid  in  front  of  main  obstacles.  They 
are  to  be  found  between  high  water  mark  and  the  first  continuous  fencu   
or  in  fields  covering  the  main  defensive  position  and  obstacles.          
noted  have  had  the  following  approximate  dimensions:-
Height  4  - 6  in. 
Lbngth  of  diagonal  of  diamond  - shaped 
section  4  - 6  ft. 
Width  of  obstacle  .12  - 2C  ft. 
In  the  fields,  betwe0n  road  approaches  to  DIEPPE)  the           
type  was  r&ported  by  Ps/W:- A  quadruple  fraffiework
j
each  frame        aF-
froximately  1  yard  squarb  with  diagonal  strands.  The  depth  of  the          
was  13  ft. 
Details  of  alarm  devices  attached  to  trip  wires  are  given  in  para.9. 
2.  APRLJN  TYPES. 
These  may  bt  single,  double,  or  a         of  double  apron        
emploing  angle  iron  or  screw  pickets,  the  former  usually  embeddei    
concrete  to  a  dbpth  of  about  18-in.  A  coil  of  dar-nert  - type  may  bE; 
found        thb  double  ,apron  and  sorretimes  another  coil  is  fixed  on  the 
top  of  the  fence.  For  one         apron  fenCE;  the  following  are             
dimensi or.LS:  -
Height  of  obstacle 
"  "  n 
Width 
" 
If 
4  - 5  ft. 
(with  coil  on  top)  7  - 8  ft. 
up  to  9  ft. 
The  standard  German  obstacle  in  depth  is  shown  in' Plate  1.  The 
obstacle  consists  of  Simple  wirb  fences  about  5  ft.  apart            b
J
' 
criss-cross  wires,  the  spaces  btitween  them  filled  with  barbed  wiru  in 
spirals  sbcured  to  each  other  and  to  the  paints  of  intersection  of     
criss-cross  wires.  Aprons  are  provided  on  the  front  and  rear  a.ces  
. A  type  of  apron  fence  erected,  it  is  believed,  somewhere  ir  West 
Gbtmany  is  shown  at  Plate  2.  The  similarity  between  the  wire  here  9.nd  th",t. 
described  iL  para.  10  will  be  noted. 
3.  C0NCERTIN)   
There  art;;  two  tYPt-s  of  standard  con.c0rtir.a,  the:  S-rollc -(barhl-d.;, 
and  E-rolle  (plain).  These  are                 to  as          - type.  Single, 
double  or  trir-lfj  coil  are  us(;d  wi th  anglE;  iron  or  screw  pickets . Triple  coil 
is  oft0r.  fixed  on  promenade  railings  (Plate  3).  Some;tim(;s  .coils  may    
found  s',.lpported  on  and          to  concrete  posts,  interwoven  between  concr(;tl: 
dragons  tð  and  fixed  on  top  of  walls,  quays  etc. 
4.  "B2UN"  (j]STACLE. 
A  number  of  reports  have  beenreceiv0d  that  the          have          
this  obstacle,  which  is  of  French  design  (R0seau  Brun).  The  following    
tails  have  beBn           by  the  Fighting         in  this  country, 
( a) 
fenc;: 
Dimbnsions. 
diametBr  of  unit,  extended  3  ft.  7  in. 
18ngth 
" 
"  " 
65  ft.  7  in. 
w8ight  of  ur.1i t  4C  lb. 
" 
per  metre  2  lb. 
n 
II 
foot  9.5  oz. 
The  above;  two  sets  of  figures  include  0.2            for          wire. 
The  following      the  approximate  dimensions  for  a  triple            
height 
width 
6  ft.  7  in. 
7  ft.  3  if.1o 
(b)  Description. 
This  obstacle  is  designed  to  barricade  roads  against  the  attack  of 
light        A.F.Vs.  The  wirG  stops  the  vLhicles  by  wrapping  itself       
tracks  or  whu0ls  which  are  thus  immobilis8d.  An           is  composed  of 
idE-ntical  ULi ts  (;xtend8d  across  the'  road  and            parallel  to  one  anothor 
in                   is  a  hollow  cylinder  or  spiral,  the  surface  of  which  is 
composed  of  large  mesh  wire  notting  of  0.75  mm.  (O.03-in)  steel  wire        
A.C.  54).  Each  spiral  comprises  6L  coils,  connE.:ctcd  in  Fairs  :1t  seven  pOints. 
( c)  Er e c t i  on  
To  placo  the  obstacle  in  position,  two  men  take  hold  of  a  unit,  ono 
at  e:-.ch  end,  and  draw  it  out  by  walking  backwards  s'tlay  from  each  other.  T1.(;; 
unit  should  be  laid  loosely  across  the  road  to  be  barrud,  the  ends  being       
and  should  l-xtend  well  beyond  each  side. 
An  effective  obstacle  against  single  wheeled  vehiclbs,  and         
vehicles  of  nine  tons  Or  less,  consists  of  40  coils  placed  in  depth  touching 
uach  other  and  in  one  layer.  Six'  men  can  erect  such  an  obstacle  in  half-
an-hour .  The  total  weight  of  wire  required  is  720  kg.  (1590  lbs.) 
Thb  obstacle,  which  is  put  in  position  very  quickly,  is  almost 
equally  (;asy  to  remove;  it  therefore  should  be  covered  by  M.G.  fire  to 
prevDLt  the  crews  of  attacking  vehicles  from  removing  the  obstacle  from 
the  road. 
Thl,  obstacle  should  be  placE:;d  at  defiles  'on  the  road  where  they 
canrwt  he  by-pass6d Ii. e .  roads  in  woods,  bridi:'(;  approaches,  roads  in  cutti ngs 
or  On  emb,an1cmen ts I  villages,  etc. 
The  dt.:pth  of  the  obstacle  is  considerable,  of  thE:;  order  of  50  m. 
(164  ft.).  If  a  bottleneck  of  this  length  cannot  be  found  on  the  road,  or 
if  the  M.G.  which  is           to  cover  the  obstacle  cannot  do  so  for  such  a 
depth,  it will  be  necessE:l.ry  to  place  the  coils  in  two  layers  one  above  the 
other.  This  arrangement,  although  it may  halve  the  depth  of  the  obstacle, 
rsquires  more  time  for  erbction,  and  definitely  causclS  the  obstacle  to 
lose       of  its  efficiency,  above  all  when  it  is  attacked  at  SPeed,  so 
that  it  sho-Il.ld  only  be  adoptt:::d  as  a  last  resort .. 
- 2  -
When/  
J     ..  h .. , 
,.'   I  .:",.  ,.1.    
When  the  width  of      roa.d  to  be  barred                  ba;rtir  to  bv 
attacked  by  several  vt.;hicles  sidt;;  by  sid8,  it  is  n8CfJSSary  t.o:'rise  the 
numbtr  of  cOils  in  the  obstacle  to  50.      
Cd)  Strengthening. 
If  the  obstacle  is         to  be  att..'1..Ckerj  by  'pow(:rful  tr"  ckt,;;d  vt..:hi 
cles,  such  as  tanks,  the           method  of          it          of           
rc 8i s tanct,;;  is  to  place  on  thG  nEar  c;ds'l,  a  cer tain  numbGr  of  light  infac try 
minbs,  carE:fully  camouflaged.. 
5.  WIRE  NETTING. 
Thb  use  0  f  l.,td sis m&n ti oned  in  a  GLrman  manual' and  call(;;d 
11lJiascht;ndrahtzaW1".  Thl;  netting  is  intendbd  as  a  haGty  obsta,cle  ae;,::linst 
infar:.try:  Th::- document  stat\...s  that  it  should  bt..:  ,secured  lightly  to  thl';; 
g,round.  wIth  WIre  and  pickt:ts.  The  standard         is  pr'obaoly  5  ft.  6  in. 
for  this       of  matt;rial. 
It  was  bncount0rbd  in  front  of  barbl,d  wirG  in  clbfts  in      cliffs 
(DIEFPE  raid)  and  watl  prob'.tbly  intend.E..d  to  prEVtnt  tht..  quick                of 
bangalorb            
6.  .SNAaES. 
Tht)  Germans  rE:;coIT:ffiEmd  the;  use  of  snares  (Drahtschlingcn)  in  all 
,types  of  cour  .. try  as  anti-pE:rsonnel  obskJcle:s lowing  to  the  ease  wi th  whi cll 
they  can  bb                 diametar  of  the  wire  used  should  be  0.04  -
0.08  in.  and  it  should  form    loop  about  1  ft.  diam.  Two  or        snarE:;S 
may  be  secured  to  a  sinf:le  woodLn          I  ft.  8  in.  - 2  ft.  (j  iL.          
or  a  Single  snare           to  a  la-in.  bar  driven  into      ground  at  45 
     pOintin[,  away  from  the  dlrl..:ction  of  attack.  Snar(;s  should     S0t  at 
intervals  of                2  ft.  6  in.  in  sevLral  rows. 
While  no  mE;ntion  of  snc9rbS  has  been  made  in  reports from  (Jccupit..:d 
Europe,  their             is  to  be  l;xpectt;;c  .. 
7.  KNIFE  RESTS. 
These  are  constructt.;d  of  angle  iron  or  tirr.btJr  fraIIlGs.  Long             
of  woodl ... n  knife  rE..S ts  have  been  seen  Or  ..  thtj  bt;;achos  above  high            Ifjc:.:rk 
(Plate  4).  Photographs  show  that  in  somu  cases               may  consist  of 
four  wooden  knife  rests  connected           by  a                              
show  two            rows  of  knifo         one  behind            with  thG       
brJt'tlebfl  varying  to  a  considerablt..  cxtunt.  Tho  approximatL!  dimt;nsions  of 
timbbr  knife  r8sts  are  as  follows:-
Height  of  ob3tacle 
Width  If  " 
Distanco          trestles 
Length  of  4  - trestle  unit 
about  4  ft. 
"  4  ft. 
"  4  - 5  ft  
fI  12  - 15  ft, 
Thbrb          to  bE;  considerable  variation  in  th0  distances         
tr8stlcs. 
Timber        rests  are  ih  USb  on  a              for                 
and  pbdGstriar:.  t;aps  in  wc5,lls  Rnd  inland  to  block  rOb,ds. 
The        iron       of  knife                to     little  uS6d  iL 
UCC11pi8d  Europe,  r(;c(;nt  reports  have  rl;i'vrr(;d  to  them  vaguely,  but  it 
protr,bly  8xists  in  some  quantity  in  Germany  from  which  it  is  bt.;licvt;d  tht2 
pho tograph  at  Pla te  5  Wf.iS  tELk8n.  'rh0  heavy  gaUe;(;  wirt...,      cri b(-d  in  '.,'       Ie I 
can  bG  seen  on  this             
8/ ... 
Althou{:,h  th!;1re  is  e,  certnin  amount  of  standardised  construction 
thcr(;  c;,re  malJ.::r  dE-pR.rtures  thert;lfrom.  Il'he  following  must  be  condidLrvQ 
only  as  a        to  what  is  to  be  expt;ctl:-d. 
    Vertical         
0ne  tyye  of  vertical  bRrbed  wire  fence  is  illustrated  at        6. 
Th(.;  81 tt.:  is  probably  the  entrance  to  a  works  or  other  restrict8d  10CD,li ty 
and  this  kind  of  barricade  is to  be  found  round  one  railway  station  Wh1.C;L 
is  a              Bty.  position. 
In  dune  coun try  and  qUiet  parts  of  the  coast  two  or  three  of  tht 
        may  be  found  together,  from  4  to  8  ft.  apart,  each  with  5  or  6 
strand.s  of  wire.  The;  space  butwl;;!en  is  SOffitl  tim us  filled  wi th  a  'IJo/irc 
t;ntant:'lemE::.D. t  andi or  minus.  The  wire  is  suppor  -by  woodt::n  possts,  anf1f-'lE;-
iron  orsare-wpickc:ts.  Tht;  height  of  thE.:  !'cnces  4:  - 5  ft.  QJIl..;  0-
these.                 may  havo  blBn  erl;.;cted  by  landowners  and  farmers  and  thGr'.:fore 
have  no  rarticular  military  fieanet. 
Platt  7  shows  two  parall(;l  fences  wi th  bn,ck  struts  and  Plate  8  sllO,JS 
tt..rt.;u  parallel  rows  of  wire  fence  in  dune  country.  In  thu  latter  note       
single  wire        running     right  anglbs  n0ar  the  point  marked  'X'. 
A  new  type  of  vertical  fencl;  has  been  rE:fort(;d.  It  consists  of  stt.;,.;l 
pickets,  embedded  in  tht;  top  of  a  sea  we.ll,            about  4  ft.  hiF=.'h.  iJ:LI.:' 
pickets  arL  about  8  ft.  apa.rt  and  have  5  strands  of  b'.:!.rbed  wire  Flnd  .'3  str:::'Juds 
of  plain  wire.  J!"rom  the  bottom,  the  2nd,  4th  and  6th  strands  art;  plain. 
r.rho  tops  01  the  pickets  are  bE;;nt  back  and  eRch  bay  of  fenet;!  has  two  barbE::d 
diaE,ono,ls  from  tht;  6th  strand  to  the  foot  of  thL!  eke t. 
At  one           of  minor  importance  the  staggered  walls  of  the  road 
block  !:;,rE;  supplbmbnted  wi th  thr(;1;.;  barb0d  wirl:l  ff..;r.lc0s  on  each  sidE;  of  the 
block.  Thl;  skc;tch  providod  by  source  indicatus  that  only  p(;)dt;;strian.  traf 
fic  r;!-'L  rl(;f::,otiatL:  tht.;  wire  and  then  by  walY.:inb  to  and  fro  bet'l;vl:en  the 
parallcl  lin_s  of  the  fences. 
At  OilC;;;  plaCe:  round  bars,  loopE:d  to  resemble  long  sereW  }Jicktts, 
have  been  lE:!t  into  the  top  of  a  sca  wall  and  then  bt;nt  forward  towards  thc;;; 
sea  ;',nd  hang  down  the  face  of  the  sea  wall.  Barbud  wire  is  fixed  to  thr:: 
bars,  horizontally,  vertically  and  diagonally. 
A  r  wirb  obstacle  is  shown  in  Plate  9,  Note  thu  wire  hanging 
down  thG  fRee  of  tho  sea  wall  and  the  gap  between  the               and 
thb            railings. 
A  wir,e  obstacle  on  the  western  e<.1.ge  of  a  mole  is  believed  to  consist 
of  a  four-strand  fence,  supported  on  steel  pickets  at  about  12  ft.  intervals 
embedded  in  the           wall  and  with  a  single  coil  of  barbed      WOvt;n 
into  it .. 
In  s,  the  st.;a  has  beaten  down  wire  fences  and  maintl;;!nancb 
work  is  being  constantly  carried  out.  Iron  pickets  are  reportBd  to  have 
              with  a  1  ft.  4  in.         base  on  certain  6xposed           
of  the  coast. 
TL.f:;  typc:;  o.f  wire  obst?cle,  shown  in  Plate  lOt  is  near  a  pillbox 
and  8i     or  ... r ..  prombnade. 
(c) /  . 
- 4  -
(c)  Wire  in  cliffs. 
in  gullies  and         in  the  cliffs  the  wire  is  laid  in  a       
entanglement.  The  wire  is  often  continued  as  a  single  fence  up  to  the 
cliff-top  on  either  side  of  such  feature.  About  half-way  up  the  side  of 
these  gullies  it has  been  noticed  that  the  wire  is  a  little  eaSier  to  pass 
through.  The  use  of  wire  netting  is  mention8d  in  para  4. 
(d)  Siting  on  beaches  and  sea  walls. 
The  "lire  is  usually  straisht  and  roughly  -parallel  to  the  shorb  in 
front  of  strongpoint  localities.  In  between  these  localities  the  wirt 
juts  out  towards  the  sea.  The  length  of  the  arms  of  onp  'dog-Ieg
l 
may    
over  100  yards;  olsewhere,  wire  generally  follows  an  irregular         
In  addition  to  the  more  standard  types  mentioned  elsewhere  in  tillS 
chapter  the  Germans  haV8  erGC ted  barbed  wir.8  in  a  vari ety  of  ways.  A 
selection  of  these  are  described  below. 
(i)  Plate  lOA  shows       fixed  to  the  top  of  a  sea  wall.     
report  states  that  iron  pickbts,         square,  are  let  into 
the  wall  and  the  wire  fixed  as  shown.  The  vertical  pickets 
also  carry  horizontal  strands  of  barbed  wire  alon  the  top 
of  the  SGa        
(ii)  Plate  lOB  is  a  sk0tch  of  a  wire  obstaclo  reported  on  quay 
walls.  It  consists  of  long  rolls  of  wire,  attached  to  ropes 
which  can  be  let  down  over  tho  sides  of  quays  to         
scaling  by  landing  troops.  It  is  probably  somG  kind  of  wir6 
netting  nailed  to  slats. 
(iii)  A  reliable  report  mentioned  the  construction  of  an  inclined 
wire  obstaclt- betw8(:m  the  top  of  a  wall  and  !=l  river  bed  on 
one  of  the  prinCipal  estuaries  of        Between  the  toe 
of  the  obstacle  and  the  sea  wall         posts  were  erecttd 
to  take  tho  weight  of  wire  at  about  mid-span.  This  obstacld 
is  now           to  have  proved  a  failure          of  tidal 
influences  in  the  estuary  and  that  it has       replacod  by 
a  simple  "cattle"  fence  along  th0  top  of  the  sea  wall. 
(8)  Depth  of  wire. 
The  distance          the  outer  and  inner  wire            of  a 
strongpoint  varies  with  the  topography  and  importance  of  the  sitG.  It 
may  b8  as  small  as  30  - 60  yards,  in  others  it may  be  betweun  70  and 
130  yards,  or  even  as  much  as  20G  yards.  In  general,  the  distance  from 
the  outer  edge  of  wire  to  the  nearest  pillbox  or  other  firing  posts    
not  less  than  30  yards. 
(f)  Combined  fences. 
A  typical  example  is  as  follows:- A  trip-wire,  immediately  buhind 
it  a  trestle  fbnce,  and  some  Ie  to  2C  yards  further  back  an  apron  feGC0; 
th8  total  depth  of  the  wired  area  may  be  30  - 60  yards.  vn  the  sea-front 
of  towns  there  is  generally  an  apron  or  trl:stle  ft;..nct:  on  the  beach  c,nd  a 
dannbrt  tYPE;;  (or         fGnce  on  tht;  top  of  the  St;a  wall  and  promenade. 
(g)       with             
Wire  is  normally       to  fence  off  all  sides  of  a  minefielQ. 
Generally  speaking  these  fences  consist  of  a  single  row  of  posts  with  5  or 
6  strands  of  wire.  une  P/W            a  fence  which     said  was  standard 
for  surrounding  minefields  and  that  men  were  taught  to            it  as  such. 
It  consisted  of  3  horizontal  strands  with  diagonal  wires          pickets 
or  posts.  The  fence  was  4    5  feet  high.  The  diagonal  wire  bracing  ffiay  be 
the  "clue"  to  what  is  behind  the  fence. 
DE Cst ASS I  Ft EO (h)/ ... 
Some  road  blocks  consist  of  a  wire  entaglement  or  fence  on  each 
side  of  the  road  with  the  gap  between  closed  by  movable  gates  of  various 
types.  The  use  of  wire  as  the  principal  material  for  road  blocks  has 
now  been             at  all  places  wmich  are  seriously  defended        
On  minor  obstacles  connected  therewith. 
(i)  Wire  with  ditches. 
There  is  generally  a  thin  belt  of  wire  on  the  outsidb  of  the  ditch. 
Thoro  is  no  information  that  the  Germans  have  laid  wire  in  ditches,  this 
may  pe  a  little  surprising  since  official  documents  stress  the      of  wire 
to  make  the  obstacle  anti-personnel  as  well  as  anti-tank. 
(j)  Wire  with  walls. 
Concrete  walls  in       instancts  are  provided  with  hooked  bars 
for  lashing  wire  to  the  coping  of  the  wall.  Wire  is  to  be  expectbd  on 
or  near  most  of  these  walls. 
(k)  '!fire  under  water. 
      nOw  appears  good  evidence  of  underwater  beach  obstacles. 
Un  BELGIAN  beaches,  oblique  photographs  seem  to  show  "lire  at  low  wRter 
mark.  uther  sources  of  information  also  say  that  it  exists.  There  is 
no  information  available  on  the  deSign  of  the  obstacle. 
9   ALARlvl  1AlI RE 
There  have  been  a  number  of  'reports  of  wire  being  charged  with 
electri ci ty.  une  P/Vl  source  who  had  1J\lorked  on  the  Siegfried  Line  said 
that  in  these  caSes  there       two  plain  copper  wires  carried  on  glass 
insulators  and  his             was  that  the  top  wire  was  electrically 
charged  and  the  bottom  wire  was  connected  with  some  kind  of  electrical 
warning  device.  The  p/W  further  stated  that  a          number  of 
stretches  of  wire  had  not  been  provided  with  copper  conductors,  prt::sumably 
for  the         t  of  their  own  troops-.  It  is  not  known  if  thes;;  electrifiud 
fencGs  exist  to-day.  So  far  as  the .uccupied  countries  are  concerned  this 
ty]Je  of  obstacle  might  be  tlncountered  on  very  special  installations  and  is 
not  to  be  0xpE;cted  elstwhere. 
It  is  nOw  established  that  the  enGmy  uses  a  warning  device, 
consisting  of  flOOdlights  actuatt:d  by  tripwire,  in  front  of  beach  strong-
points.  At  one  point  the  trip-wire  is  sited  about  Ie  ft.  outside  the  wire 
perimeter  and  is  supported  on  short  ckets  6  - 8  in.  above  the  ground. 
Immediately  the  trip-wire  is  touched  the  entire  area  is  floodlight; 
the  source  was  unfortunatuly  NuT  able  to  discover  the  type  of  lights 
used  or  their  location. 
une  type  of  standard  trip-wire  alarm  (ALA..
1
i.HSCHUSSGERAT)  is  8.S 
follows;-
(a)  Description. 
The  equipment  is  illustrated  at  Ple.t0  11.  Although  a  detailed 
description  of  tfH;;  eQuipment  is  not  available,  it  appears  that  the 
device  consists  of  a  box  (1)  with  A.         at  the  top  into  which  the  alarm 
cartridge  (2)  (Alarmschusspatrone)  fits.  Through  the  bottom  passes  a 
         wi th  a  T-shaptd  head  (3)  bv          it may  be  pulled  down,  against 
a  sprlng,  for  cocking.  U 
AI    
- 6  -
           
i         "1  f';_     1    . - . 
,  A  spring  loaded,  right  angle  t'                               f 
is         'on                      which                 "  .            
the  s trJ.ker  pl.n  in  the  cocked  .posi tion.  To  the  centtlf'            ,'"  c, .I
S 
fastened  a  clamp  (6).  whose  jaws  grip  the  wire  used  to  raise  the     m. 
Thi s  wir:  may  be  a  strand  of  the  exi sting  wire'  defenses I  a. special  wire 
trip,  One  of  the        used  in  binding           an  obstaole  such  as  an 
abattis,  etc. 
The  alarm  cartridge  (2)  is  of  signal  cartridge  ty!,>e,  83  mm.  (3i-in.) 
long  and  27  mm.  (1  1!16-in.)  diameter,  weighing  70  gm.  (2
2 
oz.).  The  -body 
is  paintud  black.  Its  recognition  by  feel  is  made  easy  since'  its  sealing 
disc  (7)  extends  over  the  outside  and  the  rim  (8)  of  the  base  is  half 
smooth  and  half  serrated. 
(b)          up  the  device. 
A  picket  (9)  of  T  cross  section  is  driven  into  the  groUnd  near  the 
wire.  The  device  is  well  lubricated  and  slipped  over  the  picket  to       
it is  then  fastened  by  the  clamps  (10).  By  positioning  the 'retaining 
ring  (11)  the  eqUipment  is  held  at  such  a  height  that  the  clamp  (6)  engages 
easily  with  the  Wire. 
The  wire  is  placed  between  the  jaws  of      clamp  and  locked  in  such 
a  position  that  the  wire  is  not  under  any  tension  and            does  not 
tend  to  move  the  lever.  Slight  pulling  or  pushing  of  the  wire         
however,  be  sufficient  to  operate  the  device. 
The  alarm  is  tested  by  cocking  (that  is  by  pulling  down  the  T-
shaped  head  (3)  underneath  until  the  coCking  stop  engages  with  the  fork: 
of  the  lever  (4)  and  moving  the  wire  slightly  when  the  striker  pin  should 
rise. 
The  alarm  is  loaded  by  pulling  down  the  retaining  spring  side  wall 
(12)  and  sliding  the  alarm  cartidge  in  from  the  front,  over  the  striker 'pin. 
The  device  is  then  cocked  as  before I  after  which  the  trip  wire  must  not  be 
touched. 
(c)  Action  on  firing. 
      tbe  alarm  cartidge  is  f'ir(;jd  a  flame  about  6  ft.  high  and  last-
ing  for  lQJ  .,etonds  is  produced.  During  darkness,  this  flame  will  illuminatu 
the  surroundings' within  a  radius  of  50  ft. 
(d)  Safety. 
Although  the  alarm  cartridee  closely  resembles  signal  cartidges' 
tired.  from  the  standard  Signal  pistol.  it  must  on  no  account  be  used  11'1i  th 
that  weapon. 
10.  HEAVY  GAUGE  WIRE. 
At  Plate  llA  are  details  of  a  heavy  gaugE::  wire  probably          as 
Simplex  - Stacheldraht).  The  wire  consists  of  a  single  square-section 
centre  strand  of  3  x  3  mm.  cross  section  (1/8  x  1/8  in.),  twisted  once;  in 
approximate  2-inches.  The  barbs  aru  twisted  on  only.  Vickers          
is  197.  This  type  of  wire  has  been  found  on  the  coast  of  Franoe;  tho  extent 
to  which  it has  been  used  is  not  known  but        it is  of  standard  manufacture 
no  surprise  need  be  occasioned  if further  information  revealed  it  to  exist 
On  an  appreciable  scale. 
The  Vickers  hardness  of  British  wire  are  as  follows:-
11.  STANDARI          IR0N  PICKETS. 
Plate  lIB  figs.  1  to  4  show  the  four  types  of  standard  German 
pickets  for  the  erection  of  plain  and  barbed  wire  fences.  These  types  are: 
(a)  Screw pickets  (Fig.  1) 
Gbrman  designation;  "Hindernisschraubpfahl".  Used  in  soft  ground. 
(b)  Tubular  steel  pickets  (Fig.  2) 
German  d.esignation;  "Hindernisschlagpfahl  aus  Stahlrohr".  Used 
in  medium  ground. 
(c)  T-secti.on  pi cke ts  (Fig..  3) 
German  designation:  "Hindernisschlagpfahl  aus  T-Eisen".  Used  in 
hard  ground. 
(d)  Stand          (Fig.  4) 
German  deSignation;  "Hindernisplattenpfahl".  Used  in  sandy  ground. 
All  four  types  are  made  in  three  sizes,  with  lengths  of  1.00,  1.75 
and  2.00  metres  (3  ft.  3  in.,  5  ft.  9  in.,  and  6  ft.  7  in.).  Weights  of 
      pickets  are  as  follows. 
Type  Lt.;ng th 
Weight   
Metric 
Bri tish  . 
Screw 
1,00  m.  1.90 
     
4.2  Ibs,  . 
1.75  m.  4.90 
11
10.8 
II 
2.00  m.  6.70 
" 
14.8 
" 
Tubular 
1.00  m.  1.95  .  4.3  Ibs. 
I 
1 .. 75  m.  4.50  9.9 
" 
2.00  m.  5.00 
tI 
11.0 
If 
T  - s8cti on 
1.00  m.  4.40  kg.  9.7  Ibs. 
1.75  m.  7.70 
II 
17.0 
" 
2.00  m.  8.80 
n 
19.4 
" 
I 
Stand 
1.00  m.  8.0  kg.  17.6  Ibs. 
1.75  m.  10.  3 
II 
22.7 
II 
2.00  m.  11.  0 
" 
24.3 
" 
- 8  -
Plate  I 
J 
..... 
r' 
/'-/ 
I.:.  I 
I 
/ 
,1 
{ 
t 
< 
J 
(I  ) 
\,1\ 
J 
M i.IO &/782-
I         J.fP. 
T 
6-7" 
1 
L 
Shore 
    Wall 
1 
T 
Sea  Wall 
Plate  lOA 
\ 
  
, 
'. 
Plate  10 B 
M  ,.  '0 b/749 
J ~ n Q .  A - ~  N3w 
/ 
TR.IP  WiRE  ALAR.M 
Plate  II 
Plate  I ~  ~ 
w 
-
." 
GERMAN          fOR,  WIRE  OB5TACLE5 
       10 b     
.TtI ne    /I&'t4 
Plate  liB 
     c,p  T Jec./'/On 
   
  
   
  
 
II 
e 
     
.f:'  4
N
_j 
.1".]" 
9'" 
 
S'S" 
..,.- j 
 
al.t 
 
II 
I 
:e 
"si' 
41=1 
      
                                    
FIG.4. 
GERIYJA-N  PICKETS  FOR- YYIRE  OBSTACLE!) 
Plate  118 
MI. 10 b/7
44 
Juncz.  43  16't4 
 
1.  GElJERAL. 
The  following  information  principally  concernS  types  of  contruction    
          BELGIUM  and         
The  use  of  concrete  in  the  construction  of  walls  in  all  strongly  defended 
a:reas  is  common.  Walls  are  used  to  ,block  streets  and  roads  in  coastal  towns, 
at  the  approaches  to  key  pOints,  and  on  the  outskirts  of  towns  generally. 
Access  to  a  built-up  area  from  a  beach  is  often  blocked  by  a  continuous  wall 
along  the  entire  sea  front  and  where  the  wall  is  sited  along  the  building 
line  the  ground  floor  window  and  door  openings  are  filled  in  with  brickwork. 
The  wall  is  sometimes  in  front  of  the  building  line. 
)rr .if"i  a  study  of  the  avialable  photographs  th0  standard  of  workmaSnsldp  on 
th8se  walls  appears  to  vary  from  good  to  fair.  Timbur  shutterinE  is used 
almost  exclusively,  in  fact,  there  Ims  b00n  no           of  the  use  of       
'shuttl:.-ring.  The  timber  shutt0ring  has,  on  some  si tes,  been  very  rou[hl.,y 
fix(;d  and  badly  strutted  against  slip  when  the  concret!.;;  is  pnuredj  this  is 
             noticeable  in  the  South  of  FranCe. 
The  proporti ons  of  the  concrta te  mix  are  not  known,  5,1 though  evt:;;ry  t3ffort 
has  bebn  made  to  obtain  th0m.  It  is  very  pro'ba.ble  that  local  materials  hu.vl:l 
been  used  whenuv(;lr  available  including  large  <luanti tibs  of  shore 'gravt..;l  r:.:nd 
sea  sand.  The  placing,  of  largu  stone  or  "plums"  particularly  in  the  founda-
tions,  has  also  been  rt;portt-d  from  good  sourceS.  Thu  use  of  "plums"  is  not 
likoly  in  tht;  reinforced  sections  of  walls.  The  usc  of  "plums"  in  mass  con-
crete  retaining  walls  is  comoon  engineering  practice  but  they      of  doubtful 
value  in  walls  designed  to  resist  A.P,  shot  and  explosives.  The  quality  of 
thu  cement  used  in  thE!  various  districts  is  not  known.  uno  sample  obtainLd 
from  thE,  CHERBLJURG  area  (Hotes  on  Gorman  Fieldworks  No.2)  indicated  tht-::..t, 
in  this           at  any  rate,  the  quality  of  the  cemont  was  not  equal  to 
normal  British  portland  ceDent.  A  number  of  r&ports  have  mentioned  the  USt; 
of  a  "'-'let  mix"  concrete,  which  implies  a  high               ratio  and  thE.:re-
fore,  correspondingly  a  lower  strength  in  'jihe  finished  concrete. 
The  use  of  steel  reinforcement  in  walls  and  oth0r  concrete  obstacles 
is  now  established  beyond  doubt.  Although  earli0r  reports  made  no  mention 
of  th6  usc  of  ste61,  and  it was  believed  that  littlu,  if any,  was  used,  it 
is  by  no  moans  certain  that  thu  earlier  works  are  entirely  mass  concrbte 
construction.  The  use  of  second-hand  railway  rails  in  three  rows  of  closw 
spacing  has  boon  mentioned  by a  s ouree  who  is  considered  fairly  reliable  and 
observan t.  Hooked  bars  have  bOt:m  seen  projectin  through  the  top  of  ti  ... L. 
walls  and  these  may  be  intended  for  holding  wire  concbrtinas  as  wull  as 
reinforcing  the  concrete.  In  several  localities  it, has  been  reported  that 
broken  glass  has  been  cemented  imto  the  top  of  concreto  walls,  especially 
           walls. 
In  connection  with  the  construction  of  thuse  walls,  it  should  be       
that  di tches  are  being  excavated  along  the  tOt;S  or'  \Alalls  to  ioprove  the 
effectiveness  of  the.  obstacle,  or  alternatively,  a  tank-trap  may  'bu  constructe( 
   the  form  of  a  pit  covered  with          vaultbd  in  brickwork,  road  metal 
or  r.J.lstting.  In  areas  where  large  quanti ties  of  stone  arb  rt:adily  aV'ailabl c 
from  quarries,  road  blocks  are  often  construct(;d  of  stone  and  not  concrete. 
2.  WA1LS. 
                                 fllU (1.5m.) 
"..          6:  ft.  7  ins.  (21.1'1 
"  .  frequently  reported  8  ft.  3  ins.  (2-5n.) 
"  max.  to  be  expected  10  ft.  (3m.)  to  11  ft"  6  ins. 
(3.51].)  .... 
- 1  -
Heih                  
::ninimum  6  ft.  ('  ins.  (2::L,) 
most  likoly  8  ft.  3  ins.  (2.Sm.) 
r.1ax.  to  be  expected  10  ft.  (3r..l  )  to  11  ft.  h  iT,.. 
(3,51:1. ) 
Height,  including  ditch  in  front 
probable  minimUL.1 
probable  maximum 
15  ft. 
25  ft 
Plate  12  shows  one  of  the  largest  walls  yet  seen.  The  curvod         
of  the  wall  is  formed  by  straight  shuttering  in  narrow  widths;  there  is  ulso 
a  substantial  toe  and  the  back  face  of  the  wall  is  inclined  towards  the  front. 
The  centre  of  gravity  of  this  wall  is  probably  within  the  front  third  of  the 
fOUf.i.1.ation  TNid th.  A  nunber  of  dark  marks  on  the  end  of  the  wall  wert;  Hoti c6d 
on  tL\;,  original  photograph,  SOl:!;  of  which  are  to  be  seen  on  the  illust,ration. 
The SS  1..,0,;>7  be:;  'Nood  blocks  left  in  the  concrote,  to  be  cutout  later         tL.(;; 
next         of  wall  is  bonded  to  the  old  work.  If  steel                is 
used.  in  this  wall  no  provision  has  beer:.  made  to  bond  tht;                    (if 
any)  of  TIc'"  'Nork  to  the  steel
j 
if any,  in  the  wall  illustrated. 
,A,  Y'l  tical  concrete  wall  wi th  splayed  projecting  section  of  about  :3  ft. 
6  iLs,  1s  ShO\<lll  in  Plate  12A.  The  height  of  the  we,ll  is  estinatod  as    ft. 
6  ins.          wall  constructed  in  brickwork          l ... c,ve  a  bui  behind  it. 
lm.  BLother  wall  of  sinilar  shape,  where  the  splayed  projection  was 
deep6r,  ttt;  steel  bars  n0ar  t.he  face  of  the  'NaIl  had  bl.;;en  cut  10EE;  onough  to 
pro.ject  through  the  top  of  the  wall.  The  bars  ap:pear  to  be  i  in.         at 
9  in,  c>'::!ltrE::;S,  111ith  hooked  ends  and  having  a  loop  bent  in  thG  bar  about  half 
way             tht;  top  of  thb  ',..Tall  and  the  end  of  the  hook.  The  bars  are  bt:JL t 
forward  to  oV8rhang  the  walls  and  may  be  in tended.  for  barbed  vlire  to 
scaling  landing  troops. 
AnothGr  type  of  projection,  reported            consisted  of  a  plain 
cantilevLr  1  ft.  8  in.  long  at  the  top  of  a  10  ft.  wall;  the tlJicknGSS  of 
the                 not  giVen. 
Another  type  of  concrete  wall  is  shown  in  Plate  13.  This  has  a  rounded 
top,  curved  face  and  a  ledt:'8  on  tht;;  back  of  tLI;;.;  we,ll.  The  purpose  of  tLt.: 
ledgs  has  not  been  deterDined. 
Th,:;  tYPE:;  of  wall  shown  in  Plate  13A  has,  up  to  datt:,  been  the  ::IOSt 
Cor.1L1on  for::.t  of  continuous  construction.  This  wall  is  probably  6  ft.  7  ins. 
thick  x  3  ft.  0  ins.  above  ground  level. 
(b)  Walls  with  gaps. 
The  gap  is  usually  sifficient  for  one  vehicle  to  pass  at  a  time,  A 
number  of  reports  have  mentioned  the  use  of  steel  rails  and  reinforced 
concrete  beams  for  clOSing  the  gaps;  the  former  being  the  most  common. 
Fl::;.k'14  shO-i/S  a  wall  7  - 8  ft.  high,  5  - 6  ft..  thick  at  its  basL,  huilt 
a9
r
Oes  a  road,.but  two  gaps,  one  for  road  traffic,      other  for  a 
       gauge  raIlway.  \:jnds  Of  the  walls  facing      railv/ay  are  slotted. 
to  take  rails  or  other  Daterial  for  closing  the  gap.  The  two  soctions  across 
the  road  are,built  on  the  skew  and  may  overlap  so  that  a  long  distanca  view 
of  thE::  obstacle  would  tend  to  give  tiLe  iL'l.pressior.l.  that  there  is  no       
Plate  l4A  shows  a  typi cal  wall  of  the  rourd.ed  top  type.  Thi s  wall  is 
probably  6  ft.  7  ins.  thick  x  8  ft.  3  ins.  high.  RefbrencG  is  i:lade  to  th6 
steel  hedgehogs  in  P3J't  III,  p"ara.  3. 
/  Plate  14B 
....  2   
Flate  14B  shows  a  straight  through  type  of  road  block  with  walls 
slotted  for  some  kind  of  barrier. 
Plate  15  fig.  1  shows  a  type  of  road  block  between  AMSTERDAM  and 
HAA.RLEM.  The  two  'outside  blocks  are  6  ft.  cubes  and  the  centre  block 
       ft.  long,  6              ,ft, ',wiue.  )':'Between  the  blocks  there  is 
Just  sufficier.t                                ..     It  will  be  noticed  that 
the  cycle  track  and                       side  of  tp.e  road  are  left 
unobs          v., 
Plate  15  fig.  2  shows  the  layout  of  a  large  road  block  near  THE 
         It  is  said  to  consist  of  a  wall  10  - 12  ft.  thick  with  the 
gaps  askew  to  the  line  of  the  road.  From  a  distance,  these  gaps  may 
appear  to  be  very  narrow.  Large  concrete  pyramids  are  kept  at  the' 
side  of  the  road  ready  to  block  the  openings.  un  the  banks  of  the  road 
there  are  a  number  of  wooden  posts  9  ins.  diameter  standing  1  ft.       
ground  level.  Beyond  these  posts,  barbed  wire  fences  continue  across 
the  fields.  The  widths  of  the  openings  left  for  traffic  are  estimated 
dimensions. 
Plate  15A  fig.  1  shows  a  type  of  "skew"  road  block  at  ST.  NAZAIRE .. 
Where  lliinor  roads  are  completely  blocked  the  main                have  a 
gap  sufficient  for  one  vehicle  to  pass  through. 
Plates  15B,  C and  D  show  the  types  of  concrete  road  block  reported 
from  CHERBOvnG.  Fig.  4  of  Plate  15D  is  an  illustration  of  the  design 
used  but  this 'may  have  been  superseded  by  a  heavier  and  higher  wall  in 
more  recent  construction. 
(c)  Reinforcement. 
While  information  on  the  use  of  steel  in  walls  is  very  limited  one 
refugee  source  has  given  some  details  regarding  one  particular  wall  at 
SANTEC.  A  Sketch  is  given  at  Plate  l5A,  fig.  2.  The  wall  is  rein-
forced  with  3/8  to  1/2  inch  bars  at  12  ins.  centres.  Good  sources  from 
HuLLlUTD  have  cons tan tly  mentioned  "light  profile  reinforcement rr  as 
standard,  and  thi s  agrees  well  'Wi th  an  earlier  account  of  the  SANTEe  1.'all, 
(d)  Loopholes. 
In  the  CANNES  locali ty  a  source  has  men tioned  loopholes  12  in.  'f/id.:.: 
x  8  In.  decreasing  near  the  centre  of  the  wall  and  then  expanding  to 
24  in.  wide  x  16  in.  on  the  target  Side.  Pillboxes  are  known  to  be 
buil t  into  walls  at  the  HAGUE  and  MARSEILLES  and  A. tk.  and  M.G.  emplace-
ments  behind  walls  are  very  common. 
3..  CUBES. 
These  are  used  in  the  same  'day  as  "dragons r  teeth"  but  are  also  to'  be 
found  across  hollows  in  dunes  which  might  provide  an  exit  for  vehicles.  They 
are  used  in  1,  :3  and  possibl.r  3  rows,  not  always  staggered.  In  dune  country 
they  are  generally  on  a  forward  slope  near  a  crest.  Where  the  pillars  are 
rectangular,  they  measure  about  3  ft.  on  each  side  by  4  ft.  high  and  the 
            types  are  3  - 4  ft.  drain  by  4  ft.  high. 
4.  DRAGliNS  TEETH, 
These  are  used  to  block  streets,  exi ts  from  (!I}.c:;,ys,  and  well  defined 
beach  exits  particularly  where  the  level  of  the  beach  approximates  the  level 
of  any  road  or  track.  This  type  of  obstacle  consists  of  3  or  4  staggered 
rows,  6    8  ft.  apart,  the  distance  between  teeth.:i:rt                  6  - 8  ft. 
uf  tht;  types  On  whi ch  informe,tion.  i                                 '.'.  be  rt:::gular 
pyramids  between  2  ft.  6  ins.  "a.n(l4         6:'''lns,                    obable  that 
the  teeth  are  connected  at                                     td rear';'  by - a  concrete 
   ""t\..1  ;......,  .... 
'.    
/  beam 
- 3  -
--
beam  which  would  prevent            overturning  nn  impact  from  a  tank. 
IW1,,,,pJltl'lt'm,rAximate details  of  a  rbinforc:d            dragons 
tooth  at  one                      Source  who  gav8  thlS  lnformatlon 
          that  the  dragons  teeth  were  built  in  three  sizes,  the  one 
illustrated  being  the  largest,  one  behind  th6  other  with  their  foundations 
touching.  Apart  from  the  slope  of  each  tooth  there  was  no  gap  betweun  them. 
Th{j  spacing,  centre  to  centre,  between  sets  of  three  across  the  road,        
by  6  to  8  ft.  No  details  are  available  of  the  intermediate  and  smallest 
      but  it may  be  assumed  that  the  same  method  of  construction  was      
throughout. 
Plates  17,  18  and  19  show  this  type  of  obstacle  somewhore  in  Germany. 
It  has  been  reported  that  the  barbed  wire  has  bt::en  removed  for  use  in  other 
areas.  The  te8th  are  almost  certainly  connected  by  continuous  beams  in 
reinforc6d  concrete.  The'  four  row  type  has  been  ruported  to  have  teoth 
varying  in  a  straight  incline,  from  1  ft.  8  ins,  to  4  ft.  7  ins.  high 
constructed  on  a  continuous  beam  2  ft.  8  ins.  thick. 
5   TETRAHEDRA. 
These  are  described  in  German  documents  as  being  about  3  ft.  3  ins. 
high      consisting  of  three  reinforced  concrete  beams  forming  a  tripod  and 
connected  at  their  apices  by  a  concrete  cap.  Each  tetrahedron  is  secured 
against  overturning  by  a  basal  cross-piece  (Grundplattenkreuz),  the  exact 
deSign  of  which  is,not  known,  and  is  secured  in  the  ground  by  concrete  piles. 
There  are  no  reports  of  their  use  in  occupied  Western  Europe. 
6   HEDGEHuGS . 
These  consist  of  three             concrete  beams  connected  at  right 
angles  at  thEiir  centres,  and  stand  up  to  5  ft.  high.  There  are  no  reports 
of  their  use  in  Occupied  W8stern  Europe. 
7.  CuNCRETE  puSTS. 
A           document  dated  1940  states  that  conc6te  posts  may     pre-
cast  b6twBon  double-channel  sections  and  may  be  fixed  upright  or  pointing 
            enemy,  and  are  generally  arranged  in  chequer-fashion  in  up  to 
7  rows.  Reports  state  that  obstacles  of  this  type,  2  ft.  to  2  ft,  6  ins.  in 
height  and  1  ft.  6  ins,  in  width,  have  been  used  as  roadblocks  in  N.W. 
coastal  districts  of  France. 
8.  STARS. 
Stars  haVE:;  not  bGt;n  reported  for  SOme  years,  ThtlY  consist  of  four 
reinforced  concrete  legs,  radiating  from  a  centre,  each  set  at  120
0 
to  eacli 
other,  and  each  leg  is  about  2  ft.  6  ins.  long.  The            width  of 
each  is  5  ft.  3  in,  and  the  standard  lay-out  is        rows  with  up  to  16  ft. 
between  rows. 
9   DRI CKW()RK . 
A  number  of  brick  walls  have  been  constructed  but  the  use  of  this 
material  is,  with  few  exceptions,  confined  to  the  blocking  of  subsidiary 
highways.  The  quali ,ty  of  the  bri cks  is  not  6xpected  to  be  high  and  certainly 
not  equal  to  the  best  pressed  engineering  brick  produced  in  this  country. 
The  height  of  these  walls  may  be  up  to  9  ft.  high  and  2  ft:  3  in.  thick. 
Plate  20  shows  a  brick  wall  built  across  a  subsidiary  street  having  three 
piers,  and  a  plinth;  the  thickness  is  not  known.  Many  of  these  walls  are 
built  to  protect  harbour  areas  from  trespassers  and  observurs. 
-'4  -
"11.108/783 
"'9 i-3 J f.P 
T 
t.r 
-'  I 
1.--:  - - +--
":7"---./ 
flate  1 4 ~ 
-
{y.c!e 
Track 
M /.lOB/T84 
Aug         
6' 
13'  6' 
-T 
7'  7' 
6' 
--
-
approx.  approx. 
t  .TramWdJ_ 
.c 
Barbed  Wire 
o  0  0  qin.  Posts 
                                  111_1 JI_I 
------
T 
 
-.0 
a              
C'\J 
o  0 
o 
  ... 'I in.  Posts 
Barbed  Wire 
Plate  15 
M 1.106/785 
             
D imens/on5  assumed  - Scale  10 ft = I in 
 
-= 
-
I..  3'.b" 
Plate  15A 
"'/e  - Y2"  aiam. 
bar.s  1i)  / l  in 
centre.s. 
Rough  concrete  with 
'P'/ums"  in  foundation 
...  _- ....  _--------
FOR.  ,. CNRIN 
FIGa  1 
_. 
I 
, 
I 
t 
I 
 
t 
I 
I 
t < 
' ....... _-
15  fl 
I 
I 
I 
I 
I 
I 
, 
\ 
" 
,-
, 
, 
I 
,. 
FIG.  1 
PLJ:lJ E:  is C 
FICI. 2. 
N\ '.\0 b/i89 
Rue.  43  J18W 
1
// 
   
         OPE-NING 
10'-0"     RRILWRY 
FIG.  1..  FIG.  2. 
    
FIG.  3 
       
    7'-ej' 
T 
I  .,.......  .seR 
6-01-00-3 
f::IG.  4 
    T-==.E_15_.D  ._ 
Rf:IN FORCED 
ML  10       
.Tun(l.      
Plate  16 
   
      
TYPICAL  .5JiC T!ON  OF 
FRENCI-I  RAIL 
(ONeRE-Tl: 
lEEJJ! 
DRAGO"'S 
PART  III  - s:fJtJ 
1.         3AIL.  ,  Cl A 
.  "Ins         of  obsta1:le  was,  apparently.  first  in4              
         1940.  Platus  21  and  22  were  probably  taken       10 
   repr OdUC8d  from  a  photograph" captured  in  North  Africa,  a  ,2  sLows 
thtJ  obstacle  forming  part  of  b8ach  deitlnces.  Full  details  are  n  '.  ah.1.0 
but    rec.onstruction  from  available  photographs  a..YJ.d  skttches  is  givGE    
Plate. 25. 
2.  DE  CuI :!TET . 
This  is  more  generally  known  as  the  Belgian  Elemt:nts  "e"  and  is  found:-
(a)  Alocg  opBn  beaches,  occasionally  in  stretches  over  a  mile 
sorretimes  across  the  vstuaries  of  small  streams. 
(b)  In  front  of  and  at  flank  approaches  to  defended  localities. 
(c)  As  a  temporary  obstac16  until  concrete  walls  art            
(d)  In  sllctions  as  movable  barriers  for  strebts,  bridges,  quays, 
jetti os,  and  possibly  a  modified  design  far           
Plate  26  shows  a  side  view,  the        rollers  being  partly  obscured  by 
long  grass;  uote  the  towing  hooks  at  the  rear  and  the        loops  on  thG 
side  of  the  front  vertical  membur          are  for  taking  thl;:;!  locking  bars. 
Plate  27  shows  the  sections  fixed  in  position. 
       28  and     show  the  approximate  dimensions  of  this  obstacle. 
3.  HEDGEHlJGS. 
These  consist  of  three  lengthS  of  angle  iron  connected  at  right        
at  their  centres  by  welding  or  gusset  plates.  The  latter  method  is  the 
more  usua.l.  It  is  a  standard  obstacle  (Stahl  - Igel)  and  may  'oe  up  to 
6  ft.  high  and  are  commonly  used  in  continuous  rows.  Plate  30  shows     
official         deSign  taken  from            (Bildheft  Neuzeitlicher 
Stollungsban  dated  L-;  Sep.  42)  and  it  is  interesting  to  compare  this 
illustration  with  Plate  l4A. 
In  addi ti on  to  tht:.3  movable  type  of  hedgehog,  they  may  be  found  l-Iubed-
ded  in  concrete  or  prepared  holes  made  in  the  roads  to  receive  one  leg 
from  each  secti on  when  the  order  is  gi yen  to  close  tht)  road.  It  is  w811 
known  on  beaches  of  the  French  channel  coast.  I t  seems  very  probab10  that 
this  obstacle  is  noVl  superseding  the  timber  knife  rests  on  important  ap-
proaches  to  defended  localities. 
4.  TETRAHEDRA. 
These  are  made  principally  of  an6le  section  stbel  to  block  beach  exits, 
ramps,  promenades  and  streets  leading  from  the  beach.  They  consist  of  three 
or  four  pieces  of  steel  embedded  in  concreto  with  the       welded  or  bolted. 
Plate  31  shows  thesb,  of  varyinb  hl-ights,  embedded  in  concrete  with  small 
in-situ  concrete  blocks  to  assist  in  exposing  the  belly  of  A.F.Vs  to  firG. 
There  havb  been  no  reports  of  these  being  constructed  in  more  than  one  row. 
Thert;  apprear  to 
(a)  2  ft.  6  in. 
(b)  4  ft.  0  in. 
( c)  4  ft.  6  in.  ", bol tt:d  3  it.  :3  in.  above  E:;round  level,  wi th  tho 
Gnds             above  the  join. 
/  5. 
- 1)  .. 
,....     
.          
DE"       u. 
5. 
RuLLED  STEEL  JuISTS .    
.; ....  \. 
In  recent  months              to  have  been  used  on  an  increasing  scale 
A                of  OP8,-o1'                is  ven  at  Plate. 32 .  The          
typ6  sl                        1S  shown  at  Plate  33  and  1 t  wlll  be         to 
        .weif'l          actually  constructed  in  occupied  terri tory.  The  of--
           term  for  this  obstacle  is  Schienensperre. 
It  ..    
.  til  , 
       thb  walls  blocking  the  seaward  end  of  streets  loading  to  the 
proIDE;:nadt  in  Belgian  coastal  towns,  rows  of  uprif:-'ht  rails  3  to  5  ft.  high 
are  reported  only  6  to  7  ft.  from  thE;:  walls. 
Ano tht;r  type  Sben  on  the  coas t  of  HuLLA1JD  is  shown  a t  Plato  34.  Tl:1..-
rails  are  Set  at  an  angle  of  approximately  50
0
,  pointing  seaward,  in   
continuous  concrete  in-situ  slab.  Une  report  gave  the  thickness  of  con-
crete  1'or  this  type  as  6  ft.  7  in.  and  said  that  the  maximum  height  of  the 
rail  above  the  finished  concrete  was  1  ft.  8  in. 
Early  in  the  war  thc  Frbnch  reported  a  type  of  inclined  stebl  obstacle 
which  soems  to  consist  of  pre-fabricated  jOists.  Plate  35  is  belit;ved  to 
be  a             of  this  somewhere  in  the  VOSGES  
....  2  ... 
CD  zLs      x        
R.E-All  Of-
         
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".  ,/  /  ..."  / 
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r  - lJ(..?
PART  V - TIMBER. 
   
. The  Gt::rmans  have  laid  down  in  their  manuals (J!l  fieldwork's       tYf
0S
:            ,_ 
of  tlrnber  obstacle  construction.  Timber  has  not  be(;;n  used  on,a                      
scal(..  but  Plat  37  shows  ono  type  reported  from  FRAlJCE.  The  dlmenSlons  f,r"  /  f 
are  only  approximate  and  the  horizontal  and  vertical  members  'liero  stated       
to  bb  10  - 12  in.  diameter  wi th  the  verticals  fixed  deeply  into  the  '.' 
ground.      interior  filling  is  of  sand  and  the  walls  are  strengthenvu 
by  diagonal  bracing. 
Platt;  38  sho'fJS  thE;)  standard  design  (Pfahlspurre)  to  stop  light 
tanks.  It  consists  of  four  rOws  of  10  - 12  in.           timbur         
sut  7  ft.  :.;;  in.  in  the  ground.  This  design  may  bt:  the  one  uS\;;ld  at  tht;: 
road  block  described  in  Part  II,  para.  2  (b)  Platb  15,  fig.  2. 
-0 
I 
D 
~ 
1m 
(JJ 
~ 
,:1 - 6'5/  --------rt 
I 
~ - 6 Y ~ - 1 
A  __  ~  f!;.--
';E o  5. > ... )  / ~ ~ - ~  -- - - - - ,.;*'  ;;  >;>;;;;":4 
SCALE:  '/50 
OlMEN510N5  APPROXIMATE 
I----i 
I 
&"6'" 
SECTION  AA 
GERMAN  STAGGERED  ROAD  BLOCK  ("CHICANE"  TYPE) 
t----?-' 
I  I 
" 
I  I 
,  I 
I  I 
I  i 
I  I 
I  I  I  .. 
I  ,7-3 
     
I  I 
I  I 
"  J 
\  I 
\I 
 
"""'-3" 
 
4'-3" 
 
4' ..  3-
  
4'-.::\-
   
,  .... 
I  ." ---1-- .  t'----l 
...          5-3  _I 
T 
I,  2'-7" 
I 
ti 
15'-9'" 
l : 
\  I 
V 
  
@ 
I 
I 
I 
I 
I 
I 
I  I' 
,  I 
\  I 
\  I 
" 
 
@ 
"'1 
.. 
... 
GER.MAN  STANDARD  TlMBER  PlCK.ET           
N\l.  10  til    
Au",.     ABW. 
PLl-lTE    
1. 
CRvVlSi!1;ET. 
PART  VI.  Iv:r SC:2LL.:\1TEvUS. 
II.  " 
11
')  .' 
Two  types  art;  known  and  these  are  intended  to  be  scattered  on 
ground  to         tht  tyres  of  vehiclos  passing  over  th0  area. 
(a)        39  shows  one       
DcscriJ2tion.  The  device  is  made  of  two  sheet  steel  sta.mpings  i_ 
I  mm.  (0.04  in.)  thick,  shaped  and  spot  welded  together  to  forrr; 
::t  symmttrical  object  '"Ii  th  four  spikus  forminf  the  api     of  a 
regular               The        of      stampings  are           
and  serrat(;;d  in  ordor  to  increase  the  cutting  and  pendtration 
power. 
Two  sizes  have  bcBn  recovered.  The  apex  of  the  larger, 
vlhi eh  iss tamped  L  on  one  of  the  WE:;: b s,  B tands  :3.5  in.  off  thu 
ground,  while  the  smallDr,  stamped  R,  is  2.1  in.  high. 
Both  si zes  appl':ar  camouflaged  pain tl':d  in  two  wa;yrs
J 
ei thG!' 
all  grass  green,  or  grtJon  and  buf';  the  former  SU6E:esting  that 
this  equipment  is  a.lso  intended  for  use  in  Europt;;a.n  tht.:a.tr(;s. 
Mb thad  of  use.  German  crowsfeet  are  droI'ptJd  by  plant..  in  9-
container  similar  in  all  respects  to  the  ABB  500            
bomb  containbr  (Summary  88,  para.  7).  In      sample  recovered 
thb  stencill(;d  markings  ABB  in  black  were  present  but  an;v 
subsequent  marking  would  have  been  on  the  loading  hatch  which 
was  missing. 
It  is  estimatbd  that  this  container  will  hold  1400-2000 
crowsteet. 
RGcognition.  In  most  cases  early  recognition  in  the  field,  of 
crowsfeet  will  dept;;nd  on  observation  of  the  container.  vn 
roads  the          will  be  easy  to  see  but  or.  tracks  and  fiulis 
they  may  pass  unnoticed. 
Efficacy.  When  dropped  on  to  hard  ground  or  ground  conSisting 
of  a  hard  und8r  surface  with  2-3  in.  of  loose  dust  or  soil       
it,  they  will  do  Serious  damage  to  any  tyre  passing  over  thbm. 
Their  effect  in  very  soft  soil  is  difficult  to  assess  as 
this  depends  entirely  on  the  amount  or  support  available  either 
immediately  underneath  or  which  they  may          when  dragged 
      by  the  tyro. 
(b)  Plato  40  shows  the  older  wrought  iron  type  of  crowsfeet. 
GERMAN  CROWSFOOT 
PLATE  :)9 
M  1.10 a/ir5 2. 
Noy. -42.  J.E.P. 
JJ  II        
,.  _"  ..  '-   - t        
Ihi 
I  .......  -..,----1 
I 
Tha  inf('\rmat ion  given     thi s  publication  i  6  n('\t  to  I 
be  communicated,  ei ther  directly  or  indirectly.  to  I 
I  the  Press  or tt'l  any  -person  nC't  hnl.ding  an  off.icial  1 
I pnsi t:nn  in  his  Majestyl s  Service.  1 
NOTES  ON  GERMAN  OBSTACL!S 
)1.1.10. 
The  War  Office 
october  1943 
0160/2436(M.I.10) 
!NTRUDUCTlON 
PART  I 
PART  II 
PART  III 
PART  IV 
DISTRIBUTIuN  LIST  tiE" 
     2 
STEEL 
TIMBER 
DITCHES 
1 N!J.'RU DUCT I uN 
Notes  on  Gel'mar  ...  Ubstacles  No.1  descroibed  all  the  known'  types  con-
s tructed  up  to  Augus t  1943  toc's th'er  wi th  certain  known  standard  rna terj als 
used. 
"        1""]        rt  f:l tf.::'      n       n  F:;:J1  '.,  .  .  .  . 
!  .:;\  .':  1,  "J                            'whi ah  should  be  :read  ln  conJunctlon  Wl th  the  above, 
';r:L'     t..'                      es  of  obstacle  laid  down  by  the  Germans  up  to 
        i  '"',              1942  (Bil  heft  Neuzei tli cher  Stellungsbau  September  1942). 
Information  on  wire  obstacles  from  refugee  sources  has  not  been  suf-
ficiently  conclusive  to  justify  circulation  but  comparing  the  poor  sketches 
as  are  available  with  Plates  I  to  8  we  see  that  the  Germans  have,  to  some 
extent      where  conditions  permit,  constructed  their  wire  obstacles  on  the 
lines  of  the  official  instructions.  It must  be  borne  in  mind,  however,  that 
many  wire  obstacles  are  likely  to  be  found  which  differ  very  much  from  the 
official  illustrations. 
There  has  been  no  mention  in  official  documents  of  the  construction 
of  concrete  walls,  cubes  and  dragons  teeth,  although  the  latter  were  con-
structed  in  the            line  before  the  war.  The  construction  of  steel 
tetrahedra,  de  Cointet  and  curved  rail  obstacles  are  also,omitted  from 
captured  pamphlets;  the  latter  has  also  been  a  standard  type  for  sOme       
siderable  time. 
In  order  to  }:J..ave  a  complete  publication  of'  official  types  as  distinct 
from  those  known  to  exist I  particularly  in  France,  a  certain  amount  of  t.l:1e 
information  in  Notes  No.  I  has  been  repeated  here. 
PART  I. 
1. 
2. 
3. 
4. 
5. 
6. 
7. 
8. 
9. 
10. 
11 .. 
1-4. 
13. 
PART  II 
1. 
2. 
PART  III 
1. 
PART  IV 
1. 
2. 
.3. 
4. 
5. 
6. 
GERMAN  CJBSTACLlliS 
Dnuble  apron  fence 
n  11 II 
If  If 
" 
for  snow             . 
wi th  singlE>  coil  lED 
If 
It  It 
It  double 
Apron  type  fence  - 21  ft. 
11 
'1  - 33  ft  
Cattle  fencea 
..... 
Trip-wire  obstacle 
Knife  rests 
'Wire  tn  pillboxes  in  wonds 
       barbed  wire 
.;garbed..  wire 
Standard  types  of  steel  pickets 
STEEL 
Hedgehogs 
       steel  rails 
Picket  ('lbstaele 
DITCHES  AND  BANIS 
Unrevetted  ditch 
Revetted  di toh 
Asparagus  ditohes 
Diteh  in  sandy  anil 
Bank: 
steJPed  bank 
Plate  1. 
!I 
If  (f:n- snt'".w  c('\nditinns) 
::-         single  emil 
'i 
double 
II 
2l.  ft. 
6.        type  fence  - 33  ft. 
7.  Cattle  Fences 
8.  Trip-wire  obstacle 
9.  Knife  rests 
Sa.  Folding  angle-iron  knife  rest 
10.       tn  pillbox  in  wOt"ds 
11.  Simplex  barbed  wire 
12,  Barbed  wire 
13.  Standard  types  of            
14.  Steel  hedgehog 
15.  Rnlled  steel  rail 
16.  Timber  picket 
17.  Unrevetted  ditch 
18.  Revetted  ditch 
19.  Asparagus  ditohes 
20.  Ditch  in  sandy  6('\il 
21.  Bank 
UNClASSIFIn 
             
PART  l  ....  WIRE 
1.  D(JUBtE  A!'RuN  FENCE  (?late  1) 
C-0rn1an  designatir"ln  tfFlanderzaun
rt 
meaninE;  Flanders  fence.  The  fl"lll"lw-:ng 
are  the  German  instructirns:-
Shf"'lrt  If 
rlain  'Wire 
2.  D.A.  FENCE  fuR  SNtJW  (:'late  2) 
The  fence  is  intended  where  deep  enfl",  cf'nditlf'nS  are  e:h.-pected  :"n  Winter. 
The  methnd  nf  erectif'n  is  t'he  same  as  the  ab"ve  fence.  vne  day' s       ft"r 
the  sane  number  nf  men  ia  220  - 270  yds. 
II 
German  designati"'n  "verstarkte  Flanderzaun
n 
meaning  reinff'l,rced  Flanders 
fence. 
As  will  be  seen,  this  fence  is  st't'-engthened  by  the  add,iti(\n  flf  a  cf"In-
certina  f'f  plain  f"'Ir  barbed  wire  (fir"  f"Ir  "SI!           'rhe  cf'lncertina  is  fixed 
tn  the  pickets  befnre  the  If'ngitudinal  barbed  wires;  167  rfl11s  are  needed 
per  1100  yds  (1000  metres). 
4.  D.A . FENO,E  WITH  DOUBLE  COIL  (rlate  4) 
------_.  __ .,----
If 
German  desie;nati!'ln  "Dhp-pelt  'terstarkte  F1anderzaun";'  The  f'rdinary  D.A. 
fenee  is  strengthened  by  means  (If  a  d"uble  rf'lw  f'r  cf'lncertinas  under     
         These  may  be  plain                          Tn  this  type  the          
           the  fenae'is                   the              are  fixen.  Vue' 
day's       f('r  4  F.C,vs  and  40  men  is  given  as  440  - 500  yds. 
   AFRvN  TyrE        - 21  FEET         5) 
II  '  : 
German  designatil\n  '!F1acnendrahthlnderni:s."  This  particular  des:gn  was 
referred  tfl  in  Nt"tes  nn  German  {)bstacles  Y:r;  ...  1  part  -r  para  2"  bu.t  it  Was  n"t 
knnwn  at       time  that  they  had  a  similar  layt"ut  f('r  a  fence'2l  ft.  deep. 
(a)  urder"f  wt"rk.  Mark  "ut  "bstacle.  drive  in  pickets,  fix  barb$d 
tri-pwires.  l1"'ngitudinal  barbed  wires  "'n  'pickets  and:plai.n  wire  bracing  be-
twepn  pickets.  !'15ce  tWf'l  barbed wires  c'"'ncertinas  in  the  aprf"l}l,  faCing'  the 
enemy,  cf'mplet e  pIv in  wiring     aprf'ns  und  fix        tudtnal  barbed  wires. 
(b)  Labf'lur.  4  P.C.0s  and  40  men  - 130  yds  per      
(c)  Materials. 
Lnng  pickets  (centre)  6
1 
6"  lnng 
      um  IT 
5',  8
ft
"  ,  tl 
Sh"rt  tt 
3'  3" 
11 
?lnin  wire 
3  - 5  mm. 
1 
"-
6.  APRuN  TY?E  FENCE  - 33  FEET           
The  German-designation  is  the  same  as  the  21  ft.  obstacle  and  the       
is  constructed  on  similar  lines  to  that  descri ted  in  para.  5. 
7   CA:'TLE  FENCES  (i.'1ate  7) 
If 
The  German  designat-ion  is !tKoppelzaune!l f 
UN
'et N ,  A, \teD:tion  is ,dr, awn  t,o  Notes  on  German  Obstacles  No.1         I  para  8  (g): 
I 
fi;i  _     Q'             this  design  may  be  ass(')ciated  wi th  the  layout  of  mine-
 ." i;  f            ! t" Q  9}      
(a) . '                  Hark  out  the  obstacle,  drive  in  pi cket a  and  fix 
diagonal  plain  Ylire  bracing.  Fix  the  three- rewa  of  barbed  wire.  Gon ... 
struct  the  second  fenc'e  in  the  same  way  a,nd  la\!  plain  or  b8rbed  ccn-
certinas  (UK"  or  JIST!  rolle). 
( b) 
.  Labour.  2  U.C.CJs  and  26  men  - 875  - 1100  yds.  per  day. 
(c)  Materials.  Long  pickets  5'  Sf!. 
Plain  wire  3  mm. 
One  interesting  note  in  the  German  document  says  that  in  view  of  the 
        shortage  of  material  it  is  forbidden  to  substitute  barbed  wire  fnr 
plain  wire. 
8.  TRIP  WIRE  (JBSTACLE  (rlate  j) 
Tr  .. e  German  designation  is" Stolperdrahthinderni sU  , 
The  tllustration  agrees  'I'lith  the  description  given  in  Notes  on  German 
GbstaclEs  1'
T
o.  1  l'art  I!  para  1.  It  will  be  nnted       the  Germans  illustrate 
the  USe  of  10"se  barbed  wire  withln- the  framework  of  the  obstacle. 
(a)  Labour.  1  N.C.O.  and  6  men  1200  sup.  yds.  per  day. 
s.  KNIFE  RESTS  (Plat e  9  and  9A) 
The  German  designation  is  tt  Spani scher  Rei tern.  :''h:r  it  shonld  be  30 
called  is. obscure. 
Two  standard  types  are  knnwn  but  the  timper  knife  rests  to  be  found  in 
France  are  generally  larger  than  'illustratecl  here.  The  timber           :5 
braced  in  all  directions  'vtith  plain  'lArj.re  2  rom.  thick  and  an  allowance  nf      
yds.  per ,knife  rest  is  made. 
(a)  Labour.  1  N,C.(;.  and  10  men  - 20  knife  rest's  per      
A  stcndard  tyPe  of  folding  angle-iron  knife  rest  is  illustrateQ  at 
Plate  9A, 
10.  '\lITRE  Tv  :-'ILL3()XES  lIT  W()(.;DS  (:'lat   10) 
Instructions  have  been  given  on  the  method'  to  be  used  in              
wire  obstacles  around  pillboxes  in         it  is  not        whether  this  has 
been  carried  out  to  the  letter. 
Use  is  made  of  wire  netting  to  screen  the  pillbox  (a  mDt erial  not ed  or. 
a  photograph  of' a  Dutch  pillbox),  and  the            pD,rtlculars  pro'rTj de  a 
gen!:ral  idea  of the  extent  to  which  \\Tire  might  be  expc<;!ted  in  woods. 
(a)  Materials. 
    100  yds.  of  wire  nettingt-
'icket s 
Net ting 
4  _.  rolls  eaeh  82  ft.  long. 
i' lain  wir.e 
lS4 . ft.  2  mm.  dlam. 
f or  surrounding  Wir e  nbst aclet_ 
, 
?l. ckete. 
1000 
- 6'  6"  x  4" 
-
6"  diem. 
UNClASSlflD 
plus  use  of  tree e. 
" 
" 
Barbed  Wire 
rlai n 
" 
ItS"  rol le 
( barbed 
cClncertina) 
tlK1I  roll e 
(plain 
concertina) 
1000  - 5'  3" 
400  - 3'  3" 
1.350  rolls 
200.  11 
2  tons. 
4t  tons. 
(b)  Labour .  1  pI:  6  days  @  8  hr s/day . 
x    
-
6"  diam. 
x  3" 
_  411 
diam. 
= 
33  t on"s. 
2  mm   diem. 
(c )  Layout.  The  obst acle  should  be  up  tn  55  yds .  deep  art'l Ulld  the 
pillbox.  :-'1ain  and  barbed  concertina  shnuld  be  i rregul a r ly            
.i n  the  fences .  I  The        netting  should  be  7 ft .  6  in.  high  hav ing  low 
firing  apertures  to- su it  the  level  nf  the  pillbox  lnnphnles. 
Ii.             WIRE  (Plate  11) 
This  is  heavy  gauge  wire  conSisting     a  single  squar e-sectinn  strand  of 
3  x  3  mm.  crl"'ss  sectinn  (l/a  x  l/a  in. ) .  twisted  (lnce  in  apr 'rClximately  2 
i nch es .  The  barbe  a r e  twisted  on  only.  Vickers  hardnes&  is  197.  This  wire 
is  of  standnrd  manufacture  and  it  is  pnssibl e  that  there  are  slight  var i ati nns 
in  tht'  am,. unt  nf  twi st  in  the  wire .  Crf'9S  sea titm  etc .  dep.ending  upnn  the 
manufacturers . 
12.  BARBED  W!RE  (el ate  12) 
Tt.i s          cut       a  wire  f enc e  s,. mewhere  in  FRANCE  and  is  under 
elUlminatinn.  !t  is  nf  lighter  cr,.s s  secti nn  than  "simplex"  and  the  blir'bs 
arc        at  ab('ut  1. 75  i n.  instead  ('It  O. '15  - 1  in.  A  descripti('lD  ('If  tr.is 
wire  has      been  seen  in  any  German  documents  but  it  is  presumed  t ,.  b e     
(If  the  standard  tyPes  ('If  barbed  vire  in  gener fl l  us e. 
13.  STANDARD  TYPES  (;F  STEEL  rrCKETS  (clate  13) 
, 
The  tWfI  sheets  flf  illus tra ti('!Ds. 
standard  German  pickets. .  Th ese  t yp es 
figs .  1  t,.  4  shfl w  the  fflur  types  I'I f 
are! -
. 
( 8)  Screw  piokets.  (Fig. J,. ) 
German  deGignatif""ln :  "Hindarnisschraubpfahl
u
  Used  in  snft  grnund . 
( b)  T'lbul ar  steel  pickets  ( F1g, 2) 
Ger man  d esibnatinn :  uHinderni sschl egpfahl  aus  Stahlrnhr " .  Us ed 
i n         grnund. 
I e)  T-sect1on  pickets  ( Fig. 3) 
J er man  designati on: 
-in  herd  grnund. 
IIRinderni sschl agpfnhl  aus  T_::is(>ntl. 
- 3  -
Used 
(d) 
'1ij.!.1...t 
Stand          (Fig.4) 
G-erIr.an  designatinn:  "Hindernisplattenpfahl." 
grl"':.md. 
Used  in  sandy 
All  ft'lur.  tvpes  are  mnde  in  three  sizes.  with  lengths  nf  1.00,       
and  2.00  m!=tr'es  (3  ft.  3  in"  5  ft.  9  in   and  6  ft.  7  in.).  1
T
c  a 
I"f  these  pickets  are  as  fl"11rws. 
Screw 
1.00  m.  1.90  kg. 
1.75  m.  4. 70  II 
2.0""  m..  I  6.70  n 
                   -r---l-.  9-5-k-g -
1.75  m.  !  4.50   
I 
Tu.b111ar 
2.00  m.  I  5.00  n 
4.2  Ibs. 
10. 9  tf 
If 
4.3  Ibs. 
9.9  II 
11 .. 0 
II 
-+ 
---+---             
                            ------------
T-sectit"tn 
------
L
Stand 
        
, 
I 
        I 
2.00  m. 
4.40  kg. 
7.70  " 
3.80  It 
1.75  m.  ---+ 
--------"--.---- ,  ---, 
1.00  m. 
1.75  m. 
2.00  m. 
t 
I 
I 
I 
_,,  __  ,  ____  . __  . ___               .. -.-, 
- 4  -
9.0 
10 ..  3 
11.0 
If 
1f 
9.7  Ibs. 
17.0 
n 
19.4 
\I 
17.6  Ibs. 
22.7 
" 
24.3 
If 
"" I.  10  b  /842 
SEPT.  4$  'ItJw. 
Plate  t 
   
L 
'"  .  ,     A- \0 f::l  f6 
      -IO-------.;..JI_-' 
....  ENE.MY 
-
t  I, 
3--7 
                        ' 
DOUBLE 
I  ,. 
4-1\ 
Plate  2, 
--fI_-g1IO--.......  t----9IO'-'  -----'......--
.J. 
..  , 
 
:.  , 
r--..... 
...  , 
\(J 
  ,..'  I, 
+-  10'-'  - .......  ----9.10    9,O  ..                         ... 
NJ. I  10. b/843 
I 
:iI!.PT    
DOUBLE  RPRQIV  FENCE 
(FOR  SNOW  CONDITION.s) 
). 
   
w 
Z 
Ul 
Pla.te  3 
t 
4'-1' 
1:0 
                                                                                                 8' -2-
                                             
... ENEMY  .. 
PLRIN 
, 
3'-7-
                                                                                                          --*-
I' 
I' 
I' 
I  41
2-1 
" 
-.-
DOUBLS  RPRON  FENCE  WITH  S/NGLE  COIL 
     ......                     .. :;.
           q           ..                 C'.tj. 
"           -         ____                 
.          .        
,.     .       
    <-'ft'           ";,          -:M)    ..         
     . 
\  :\""  ') 
   J' 
\  " 
-  
'-..... 
I  ..  "  I  ,  " 
       +4-11 
E.,NEMY 
  -
t 
3
1
'7" 
L 
                      
/1  2'-1" 
WITH  DOU"JL/i.  COU  DOU{3LE  RPRON  FENCE 
1---------";) 
NIl. 10  b/tJ4'5 
.I  E.PF:n IJIlW. 
i 
I  " 
3-7 
-f-
2'-1'" 
 
'1'.  10 b/l!J4 6 
.J  rr.  Jt3  /18M! 
Plate  5 
~ P R O N  TYPE  FENCJ;,  - 21 ~ O " 
Plate  6 
J  ( 
-f-i!  :.  ..j 
I 
~ k 
- ~ 
"-
.\ 
... " 
II 
\  .;,t 
9'l 
'!ri 
\,;.  , 
I 
/  ..sf 
( 
t 
~ 
) 
(I 
, 
j 
'\11 
l 
Plate  7 
OPEN  GROUND  UNDERGROWTH 
T" 
~ " ' 7 
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ + . 
2-1 
-*-
f---4 '-1I"  1- 9'-10 ~ Q  13'  --1' 
DOUBL.E:  CATTL.I!!.  FeNCt=.  WITH  .$1  OLE.  COIL.. 
ItIJ  I.  10 b/tu 
../i&PT   .e 1J8.v-
CRTTLE  FENCES 
Plate  a 
OPEN  GROUND  UNDER GR.OW TJ..I 
T 
\.1  II  .  It 
     roQ-10 
I 
                          1-,  .. 
66h>9    
L 
..seRLE  r,OO 
TRIP  WIRE 
OBSTRCL 
Plate  9 
TIMBER 
RNGL-IRON 
.1 
+- 3'/;"  -+ 
KNIFE - RESTS 
           F:ULL      
! 
'r'  ::l. ..  .5  II 
   L  1 %0  x 1 Yae.  - L.E:.NGTH 
------
AA 
tt 
5  1'\ 
t  I  II 
______ 7  \0i'2; 
B-
F        s:::\52%  ==     
I    j 
--------,--- 11  4  - ,i,  'iJI
       FOLDING               KNlf=.t;:        
-0 
-
t:) 
,..,. 
(I) 
<0 
S!) 
Plate  10 
~ 
...r-r-.J' 
,  r  ~ 
~ 
_ ~  t 
C 
II 
~ 
  I 
~ 
" 
)( 
0 
CO 
......I 
..J 
a: 
':l 
~ 
-..... 
Q 
~ 
::;:, 
0 
~ 
~ 
~ 
\I) 
l..&I 
~ 
....... 
~ 
to&.. 
C 
t--
:::, 
~ 
c:t 
-J 
M' .  10 b/7!5' 
        43  AM 
SCALE: '.-      5tZE 
 
+. 
\  f)q. 
SE:C 1     OJ:.  Ct;'lTRE:  STRAND 
4)(  F-ULL       
GE:RMAN 
   
       
!)f:.CJ'ON  OF- BARB 
4- X  F-ULL        
BAR&:D  WIRt  (.sIMPLEX) 
     
-c 
-
OJ 
C"'I' 
(D 
CeNTRE  .5TRf:lND  TWISTE.D  ONCE:.  IN  RPPRO)(.     INCHES 
SCIJLE:.:  FULL  -SIZE. 
--  
'c-+-
Cb 
at
A 
  
I ......... 
I\} 
SECTION  OF  CSNT.RE.  STR.RND  seCT'ON  OF  BflR8 
        ,)VICE:  FULL  SIZE. 
  E     AN             WI RE 
Plate  f3 
i \  n 
    
   
r  I 
.I 
  
         
+'1 
'6 
J 
       
4'1 
    
9' 
) 
r 
6;'7# 
FIG,'C. 
GE'RMAN          FOR,  WIRE            
M'.          
I 
.Ju nQ.     /J&'W 
Plate     
               
                                         
      
,3'SH 
    t 
       
 
      IIJ.-'X "-t*-
           
       
  
I-
S':!J" 
1%')(     T          
      
4
M
+f 
      
J'sfj 
r-
&'7' 
FIG.-4. 
---
GERMAN  PICKETS  FOR  W4 RE  OB5TACLE5 
) 
MI ..  10 b/744 
J 
.1uncz.     It>W 
In  n II 
PART  II'- STEEL 
1.  HEDGEHOGS  (Plate  14) 
The  German  d esignati('\n  is  If stahl-Igel
ll 
  Thi s  design  was  referrec  tn  in 
         German  Ubstacles  No,  i  Part  III  para  3. 
2.  RCJLLED  STEEL  RAILS  (rlate  15) 
The  German  designatif"n  is  nSch1enensperre."  This  design  was  referr8d  tr 
in  Nt'ltes  /"In  German  ubstacles  No.1  !Iart  III  para  5. 
1.          OBSTACLE  (nate  16) 
III  - TIMBER  ..  'I.,  \  1\          
\\"  l.f\ri);)" 
The  German  designatif"n  is                 T"is  design  was  referred  to  in 
ITl"'tes  "n  Germa.n  CJbstacles  l'Tt'1.  1  Part  V, 
PART  IV  - DITCHES  AND  BANKS.' 
1.  mTREVETTED  DITCH  (:"'late  17) 
The  Gr-rman  designatif'n  is                      (,,!Me  Nerk1eiaung
lt
 
The                     the  first  and         task  types,  anr  the  dimcnsirns 
given  arC"  the  ininimum  al1t"1wed.,  The  fi-st"  task  serve s  a IS  an  r'lbstnc1e  and  the 
       taek  is  desigped  as  a  trap . There  has  been  a  tendency  for  the  width 
and  depth     increase  and  .any  ditches  in  France  exceed  13  ft.  in  width  
.  ' ! it\                                  it'"'      l!J'"'  t,< .. " 
l
'  !                                            la, 
             t1 ..    :;'  4       It'  *i  " 
The  German              is  "I'anzerabweh':rgraben  mit,  Nerkleidung" .. 
See  nt'lt es  ('In  German  (;b steoles  lJ('I.  1  tJart  I,r  para 1. 
3.  ASPARAGUS  DITCHES  (:"lat e  19) 
Thft  German  designatit"n  is                       ....  Spargflbeete  ('Idel" 
Fischgratenhinderni s",  meaning  A.  tk  di tch  - asparagus  ('II'  fi shbt'lne  type.  Thi s 
         is useful  in  wet         and  the  ditches  are  set  at  an  angel  ('If      tn 
eaoh  t"ther
lt 
It  is  intended  that  mines  be  laid  in  the  excavated  material. 
4.  DITCH  lIT  SANDY  SuIt  (Plate  20) 
This  ditch  has  avertical  face  tf"l  the  enemy,  revetted  with  rt"lund  tilIDer, 
a         bank  /"In  Ithe  trht"lme"  side  and  the  invert     the  di tch  cf'vered  wi th  an. 
aprt"ln-type  barbed  wire  fence.  Fl"nm  the  drawing  it  may  be  inferred  that 
attenti('ln  must  be  paid  in  the  siting  ('If  the  nbstac1e,  t('l  handy  pits  and  hl"lllnws 
fnr  tipping  sUrPlus  spt"lil. 
5.  'BA11K         21) 
This  illustrates  the  ct"Invorainn  nf' slt"lping  grnund  intt"l  an  A.tk.  t"Ibstacle. 
TMo  efficacy  f'f  the  t"IbstaOle  is  imprl"lved  by           a  parapet. 
6.  STE:i1PED  BANK  (?lJite  22) 
This  illustrates  hf"lw  a  natural  high  bank  can  be  turned,  inti"  a  gr"('Id  A. tl:. 
         by  excavating  a  step  and  filling  in  any  lncal  hnllnws  (lr  fl"llds  in 
the  gr"und. 
n/206 
- 6  -
Plate  14 
T 
'5'  7" 
1 
I  " 
10  0 
T 
,  " 
.5  7 
~ 
GERMAN  ST-EE:L  OB5 lACLE  -- J./6DGI-IOG 
MI ,10  b/79b 
Rue.  4 3       
a 
1 
Plate  15 
C  b  a  c  b  a  c  t>  a 
1  1 
J: .. 
.1  .1    J.  .1   
b  a 
1-., 
b  a  a  b  a  c  a 
J.  1.  1  1  .1  ..1  1.  1  1 
5-3 
0  c 
b-'-..  a 
(.:  b  a  c  b  a 
1.  1 
l  J-t 
.1  1  J.  1  1  1 
.:!'-7" 
r  r 
- r 
r  r 
HEIGH r  01=  RRIL5  MARKED  a 
"b" 
c     11" 
GERMAN  R.5.       OB5TACL(; 
, 
, 
:  1:
7/
-
3
 
:  I 
I  I 
I  I 
" ) 
\  I 
\I 
 
""""-3" 
.. + 
4'-3" 
 
4'-3" 
  
    
  
,---
Plate  16 
I  1
41
-+ , ..  ...  0-3  6  -3  ---1 
T 
I :1.'-7" 
 
 
15'-9" 
I 
I 
I 
I 
I 
I 
I 
I 
I  I 
\  I 
\  I 
V 
@ 
I 
I 
J 
I 
I 
I 
I 
I  I 
I  I 
\  I 
\: 
@ 
@ 
.. I 
... 
GERMAN  STANDARD  TIMBER  PICK.ET  OB5TACLE 
.MI.  10  0/797 
Auu.         
FIRST  TRSJ< 
OBSTRr:LE 
.:  .:.  :;    , 
:SECOND  TRSK.  ,-
OBSTRCLE:. 
Pla.te  17 
  to 
\  11  - 5  _------'--I 
,  ' 
'-- -----------, 
DITCI-I 
/tIf1.  10. b/(358 
fE,PT431J8W 
Plate  18 
13:0' 
REVErTED  DITC/-I 
-----'1 
"  ,  1 
,  / 
V 
Plate  19 
jEeT/ON 
,                
  7  6            
4- , FT ----'lII  ........  -
4' FT 
164FT.                 
4' fT  ----Jl,  ....  I11(- 41 FT    
[J 
o 
Cl 
o 
o 
o 
o 
o 
CJ 
o 
CJ 
o 
PLRN 
o  REPRE..sE.NT  MINES 
IlSPRRRGUS  DJTCJlES 
"1'.10  b/8S9 
J 
JapT.  43  W. 
" 
"-
-
20 
" 
If  i.  /I). 6/6/iII 
.1.,,-.  .4$ I/IIN. 
&NE,MY 
Plate  2.1 
S'LOP6.  110  I  ____  ~ 
... 
,,/ 
,/ 
~  -
/ 
8 liNK. 
-   -
11/1.  10. b/862. 
.ipr !43  !J8w. 
.5TPPD  BIJNK 
DECLASSIFIED 
PART  I 
PART  II 
PART  III 
PART  IV 
PART  V 
PART  VI 
tJI.I.10 
The  War  ()ffic e 
January!  1944. 
0160/2436  (M.T.IO) 
Nc;TES  uN  GEIU1AU  uBST,A.CLES 
110.  3. 
WIRE 
STEEL 
DITCHES 
MISCELLANEl;US 
Distribution:  List  "En 
Copy  U".  359 
1'ART  I 
1 
"")ART  II 
1 
2 
3 
4 
5 
PART  III 
1 
2 
3 
4 
PART  TIT 
1 
2 
:1 
4 
PART  V 
1 
2 
?ART  YI 
1 
2 
3 
G E  R MATI  G B  S  T  A C L  E -S 
WE\11 s 
Drpg"'ns  Teeth 
vC t [lhef! ra 
                    virfields 
ubstacle            Bri0gc'Exits 
STEEL 
De  Crintet 
T et raheci ra 
           
       Steel        
rITCH]JS 
Anti-tank  ritches 
T['nk  Traps 
           Canels 
"Ch1crne"  0itches 
UlillEEWATER  vBSTLCLES 
Unc.erwnt or  't,.T1  ro 
         DhstBcles 
                   
Swing  Bvrriers 
Anti-..tdrcr8ft  LDllning  (J'lstvcles 
4. 
5.  Fig.  1. 
n 
2. 
6. 
7. 
8.  Fig.  1. 
n  2. 
II  3. 
9. 
10. 
11. 
12.  Fig.  1. 
"  2. 
13. 
14. 
15.  Fig.  1. 
"  2. 
If  3. 
16. 
17. 
18. 
19. 
20. 
21, 
22. 
23. 
24.  Fig.  1. 
n  2. 
25. 
26. 
27. 
28. 
29. 
I  N  D  EXT V  P.T,     T  E  S 
Wall  with  Gel'.  Inclined  Steel  Rpil  ubstDcle 
       "Chic[1ne
tt 
type. 
     11  GAl)  wi th       Trf'p. 
Germah  Steel  Railway  Sleeper. 
          well     ritch. 
'''nll 
              in  wnll 
        wi th              Rails. 
1"i11 b,..x  in  Anti-T[m  ..  'k:        
       wi th  Fi r(> .... st 81). 
ubstacle  rn  rfJmp  t,..  a  ,-iyke. 
Drfl.g"'ns  Teeth  ubstacle. 
If  n  n 
Drag"'na  Teeth  0bstacle. 
Drag"n  rreeth  vbstflcle  with  Gep. 
         Rr1ler 
11 If 
If  11
ubstacle  Gll[lToing  Bridge  Exit. 
De  Crintet  0bstpcle 
           ubstacle. 
Tnclined  Stc:l  Barrier. 
Inclinef.  Steel  Rail  ubstncle 
Inclinoc  Stepl  Rail  t,bstv.cle  with  Gap. 
Anti-Tank  Ditch  1tlith  Concreto  E.0vetment. 
Anti-Tank  Di tch  with  Brush  'l:lOod  Revetment. 
Tank  Trap 
n- It 
C"'vorcr  anti-tank  f.itch 
C"'v,-rec  nnti-tnnk  ,4  itch 
M.l.IOB     
P.E.F.       
PL.ATE  I. 
T 
FIG. I. 
FIG.2. 
GERMAN  YVI RE  ON  SEA        
PART  I  ....  w1:RE 
The  detpila  given                                                   1:t'('I"  1  still 
     g"''''r  a;n(l  thC'r0  hDS  bOJ:h'       rC'vf.\lufif"'nnry                      .... sign.  '!'hc 
f'Xlstcnc('  flf  thf'  type  ,",f                                                            tf'     Cxpc:ct00 
nnYWhE'T0.  ..    .....  ,:.:,-        
1.        urT  S:?..t\,  i-TLLLS  lilli'D  BE.LiCHES. 
}T ..... tes  f'n  German  upstaclrn:3  1"'''.  1.  "'rrrt  !,  T'prc.  8(b)  gavo  cot['ils  ,..f 
barbr0.  wirt'  t'lbstnel0.s  fin  sea  we.lls.  R('Ip .....  rts  .....  f  r.iff0r('nt  mrth,..rs  f'f  attrching 
thf'  wir('  hpvc  n"'w  bpon              Etl1r  Sl'Imf"  "f  thrse  ar0  111ustrntC'r  (It           1. 
Fig.  1  shf'ws  a  mpth"d  which  is  rcp"rtC'd  ns  huving  b('cn  usee  ('In  the  tf"'P 
   a  se?       8  ft.  3  in.  high.  The  8  in.  l"ng  irrn  bprs  (1)  ['ro             
in  the  st"no  c('Iping  "'f  the  scn  wnll  ane      "'ut  at  an  engle.  Thr  3  ft.  3  in. 
high  screw  cickpts  (2)  which                  int'"  th('  sea  wall,  orrry  brth 
h"riz,,'ntal      riag('ln['l  barbpr  wirr:s.  Th('l  0,..i1s  t'lf  bl1rbN'  wir"  (3)  5C't  bo-
tW80n  thp  guy             nrc       barbe'd. 
uthf'r  r0l'f'rts            B(la  walls  8nr  ml'lles                by  bprb,,(  wire 
        t"n  I"'utw[lrd  b0nt  pnglc-irl"n  -Pl"'sts,  Fig.  2  illustrates       such  nrrnng0-
ment  in  which                 stpt00  tr  bc'3  ft.           with  2  ft.      
f'utwnrds  nne  tf"'  be  4  ft.  aport.  un  thp.  inside'        ,..f  tho  wRll  is  P  ct'lntinu-
I"us  0/"'11  rf  wiro  hung  /"'v("r  thp  sifle, 
A  re-nf'rt  frt"m  BELGIUM          thrt  wnrning              flrC'  &ttuchcd     
20         int         .t ..... nick0t s  in  Rflrbeo  wir(l  f 0nC03  "n  bC'['chC's.  Thi s  may 
well  refer  tt'l  thr  Alormschussgerflt  (lcscri bef!  in  lJrt     (\n  GprIDnn  vb str-clC'>;! 
Ft".  1,       1,             9.  . 
E/64' 
PART  II  - CvlJCRETE  & BRICKW{)RK 
(r)  Dpsign 
Thr's0ction  of  woll,  shnwn  t:1t        2  is  Dnli'-'v,-.d  to     ono  of 
the  st rndnrd  d;,signs  'for  IJorth':"Wpst  Europp.  Thl s  drrwing  should  'bc 
compnrr-.d  with  Tllntrs  12  rlllo  12[1  of  Notes  on  Germnn  ubstaclos  No.1.  It 
is  nf't  knf'wn  for  cArtnin  thnt  thp  rein-forcpment  shown  is  thr  totrl 
ollownd  for  in  thp  d('sign;  from  'i'h'p  informr,tion  avoil[lblf>  it  would  npne[lr 
thrt  this  is  so.  The  bnrs  projrcting  from  thfl  front  top  corn,T  E1re 
       to  "be  'for  cnmouflnge  nUrP0'sPq,  bu,.t  it  is  knf'"rn  thnt  in        plr,cc::3 
thr-y  hEtVP  bc,-'n  used.  for  the  err'0ction  ..  f'f  bar'bed, wire .. It  is  interesti.ng 
t('l  nnte  thnt  tht>  concretf-'  is  specifiC'd  as  n  "dry  mix"  (If  1  :  2  :  4.       
l't  '  ,            < 
(un  1  y.  _,       \;:l     cl    t"  "'&I       "  ;       '"  ' 
1,   t  _;\  ';  '1  .'"  ,.--,  ",_  .   "  - I,' 
I' ) 
  , 
1 ...  ::,;,\ 'I.,  J  ' 
,  )  'g,
'A  variant  f'f  the  IDPthod  'rised  by  thp  ,G0rmnns  to  clos0       in 
wnll  rood  obstaclps  (descri
1
)ed  in' ':ra,rt  II  pnrn.  2  (b)  and  illustrc-1ted 
pt         14B  of          on,Gertnnn               FO.  1.)  is  rplinbly  rp'pnrted 
fr('lm  Fro,ncp.  In  th('  p,ltcrnntivp  mAthod,  inst8nd  of  i.,('lth  wnlls  bping 
slottpd  to  takp  thp        girdcis;' met!l  shplvps            fittr,d  into 
c'  cut-awny  scction  in  f'np  of.  the  wnll's  (""'late  3  fig.  1)',  "'h"  girders 
ClrE"  hpld  in  'P'osition- by  securing  pins           fit,  into  hrlps  (1)  in  the 
         It  will  be  nf'trd'       in  thr                             
thrower  nf'zzles  (2)  hrv('  been  built  int(l  thf'  ground  [t  the  corner  of 
ench  well. 
In  nnoth0r  WAll,  5  ft.  7'  in.  high  by  5  ft.  wide,            hns 
      mtl,de  for  the  girders  t6  be  hplu  in  posi tit:'n  by  (-Jolts  running 
l:-,t('rnlly  thrnugh  the  WF'll.  "lnte  3,  fig.  2.  shows  the  nrrnngement. 
      4  shows  R  gap          a  wall  obstacle  in  a  French !coastal 
town.  The  gop,  through  which         D  ruilwny  linp,  has  bcpn  closed 
by  steel  rails  which  Cf'me          level  with  thp  top  (If  the  wall  and 
which  slope  towDrds  the  enemy. 
Another  repf'rt  describes  h(lw  D.  gnp  in  fJ  rpinforced  cf'ncret e  w[lll 
9  ft.  10  in.  high  and  4  ft.  broDd  at  the  bo se  rnd  2  ft.  8  in.  :- t  the:  top 
cruld  be  blocked  by  iron  girdc--rs  which  fi tted  int(l  slots  in the  rond\Rfny. 
The  girders  consisted  f'f  steel  joists  eOf'ut  10  in.  web  and  8  in.  top  und 
b('ltt('lm  flanges.  These  wpre  set  in  the  rf'adway  in  tW(l  rows  and  inclined 
ff'rword  at  an  angle  of       The  front  rf'W  girders  were  the  If'nger,  the 
up-ppr  end  being  FIt  [-l  verticrl  height  f'f  abrut  8  ft,  3  in.  frl"m  the  grliund. 
The  rear  rf'W  hRd  a  vertical  height  frf'm  the  grf'und  lif  E1bl"ut  4  ft. 
;           of       in  an  [lTIti-tnnk  wall  in  !lollnnd  h[\ve  been  set-'n 
tf'  be  bl('lcked  with  dragf'ns  teeth, 
(c)  "Chicanes" 
-lAte  5,  fig  I  shf'wS  a  ff'rm  of  rond  block  crnstructed  in  the 
Sl"uth  lif  Frnnce.  It  clinsists  of  three  brick        built  rn  nlternnte 
sities  "f  thf'  rf'vd,  ,,.,hich  f"rces  tr[:ffic  t"  slf'w  down  and  zig-zag         
the  lil-Jstructi/"ln.  The  mr-in  dimcnsif'ns  rf  the  welll  [Ire  [IS  ff'llf'ws: 
Height  5  ft.  7  in. 
Length  13  ft.  I  in. 
Thickness  4  ft. 11  in. 
( d)  Walls  with  Ditches  cnd  i'ank  Trnp s. 
At  line  French  cf'Bstal  t"wn  the  nnti-tnnk  w[lll  hes  l'  g[lP  which 
cuts  thp  w[lll  I"bliquf'ly.  The  gap  is  7  ft.  6  in.  wide  and  E1  tE1.nk  trEtp 
is  8uilt  intf'  the  senw8rd  end.  This  clinsists  f'f  a  pit  which  is  rlif'fed 
f'ver  suffiCiently  strongly  tf'  tnke  light  trnffic  rnly.  un  the  landwprd 
side,  there  nre      nblltments  sl,f'ttec  tr  tnke  girders  "r               
l[ v"ut  rf  thp  gDp  is  sh"wn  [It  ""11ate  5
p 
f1g.  2.  ,      . 
\' ,'If'     _  1  _  "  ..  , ',\\\r'      , 
   ,  U\,\ 
       '7  shl"'ws  the'  wnl1"descr,ibed  'in'            en)  et"nstructed    
SUl)l)",rt  t'he  'verttc'fl'l  fei'oe  r;f  an .anti-tf'lnk  di tah,  It  will  be  nl" ted  tb t 
the  fi'nisltpd  lpvel 'I"f      wall  is  :3  ft.  :3  tn,  If''wcr  than  thp  rr:k             
"n  the         'side  ,.,f  the  di tch;: the.  wal1  1.s  thtis           frt"ID  grl"und 
f't servt.'t. i ('Iri. 
"fr ' 
At  anl"ther  French  cf'aetfll       all  rC'Rds  leflding  tf'  the  8.:'[1  hfYe 
been  bl "eked  by  a  brick  wall  Rpprnximat ely' g. ft.  8  in,  hi  ,cl"nsi Bt.lng 
('If  tWf'  l""W6  ('If  t"Irdinary  bricks.  This  may  be  similrr"t(,JP1('t.r',20.  f'f  ::i;.tes 
f'ri.          Obstficles  Nf'I.  1.  .\ssuming.  that 'standRrd
1 
French  L:''ijck  hHe  1 t'en 
USta..  this  w"uld"give.ll  wall  thicknf\ss.('If  anprl'ximrtely                BLlnd 
the  wall;  n                         5  I't.-br(\ad  by  5  ft.  deep  hns  LPEjL  filled 
up  t."  rf'lrd  levpl  with"cnncrete al'id.  steel  railway  epers  plrnted  tn  f"Tn: 
t.r
r
nsv0rse  knife           The  slt!epers  atE='  described  as  being             h, 
            ui!e>d  in  GermR'ny,  rlC'.te.6.  They  have  tn  nngle  nf  slant  ('If  ,!'J"t.:f'ut  60" 
    1'rf'trude        5  ft  ao<'ve  the  cr:-hcrete  which  w('Iuld  meF.ln  thDt,  they  PTe 
f'mtedded  tn  B  deptrJ.  ('f  apprf"ximEltely  3  ft_  0  in.  The  ends  ('If  the           
hove  lJeen  left  blunt.  A  sec('Ind            is  placed  abt"ut  ten  ftjE't  rt.Lind 
the  f'lrst  and  .he  expressit"n  ltknife  rest s ll  implies  the  use.  "f  larbed  vlire 
in  Sf'lJte  '\tiny. 
    Reinfrrcement. 
       is  further  evidence  thf't  steel  reinff'rcmpent  rJ'S  "bt:cn 
used  in  cf'ncrete  wfllls.  A  13f'Ul?ce  hve  described  the  building  nf  the         
,  trr.k  wnll"shl"wn  in  PInte  8
t 
fig,.  1 . A  tranqh  8  ft.  a.cep  by  6  ft.  6       
wide  wn's  dug,  -and  c'"ncrete  'pt'\uredintl'  the  ff'lundatlnns..  iTE',1".ticf'l  ir"n 
rf'd3  tin.  diame'ter  were  fixed "at,_,8  ,t"  12  inch  intervls  lRtC'l'G':lly  nnd 
:'''ngi tudin8.1Iy.  and  hnrizf'lntn1,rf'\'ds  we,re  fixed  at  similar ,intervr13      nd 
[f'\
1
1Ld  t('l  the  vert1eal  r"cts  by  "rdinary 'wire.  Tl;1us  a  steel  grillrge  "f 
8  t"  :12  inch  eu'bes  f'l1"  the  wh"l.e  length.  width  and  height  flf  the  wall 
Wt'S              N,...  shuttering  wna  used  l.clnw  gr(lUn'Q  level,  the  c"ncrt't  l:t'l ng 
p,.,ured  straight  int"  the  trench.  Bef're  the  shuttering  ff'r  the  l't"st  nf 
t.he  wpll  was  erected.  the  ends  "f the  vertiolll  Tf'ds  0n  the  seawr,rd        
wpre  turned  inwards  tf"  align  wi th  the  slf'ping  face  f'f  the  wnll  (  t:'  ::i, 
fig.  2).               bf"nded  intf'l  the  h('luses  "n            "f  the      
by             rf'ds  which  were  embedded  a(Jf'ut  4  ins.  intI"  e.he         'IIIF11.3. 
     wf'll,  which  tl'l('\k  3  tl"  4  days  tf"  crmplete,  WfS  built    ..  t  ;,n 
[Ingle  t"  the  h"uses"  A  \v[l11  bl('1cking  the  next  street  hod  vertic ... l  't\rrlls 
r nd  '  .  .,r{;S  'built  at  right  angles  tf'  the  h"'uses. 
Anf'ther  Sf'uI'c(:',  descr-ib'ed  as  relitt',:lle,  has  s,tFted  thr,t  p  'Well 
f:l::;T,'ut  6  ft.  6  in.  high  by  3  ft.  3  in/thick  at  thE'  of.se.  tp.per:ing  t('l      ft. 
'6  in.  nt'l'the  tnp  was  reinf"rced'  by  thrQe  Tf'WS  ('If                  rEils. 
ThE"  f"i:mdFltin,ns  weTe  Fb"ut  5  ft.  deep..  Sf'ckets  ff'r  rails  had  0t>('n  1'1',---
'pr ree  in  thE""  geps  in  the  rr"ad  nnathp  'P"si ti('ln vas  defended  by  [,  "T"  ruck
lf 
     -pillr.('Ix 'wi th  tnrt'E't  c('Intflining  n  gun'r-f  npr,rrximptely  37  mm ..     11 bre. 
,.  - ""  
Plate  8.  fig.  3 t  sho\lI's' a  loJa:
1
_:!..  in  t'ihich  the  s,t,eel  rails             
above  the  wall.  thus  inoreasing  the  effectiveness  of  the  obstacl0. 
The  strengthening  (\f  wr.lls  by  means     buttresses  2  ft.  6  i  .. 
c,e"'P  x' 9:  in.  thick  at  2  ft.  6'  in.  s-PFlcing  heS  s18(\  been              
(g)  Wall s  wi'tp  at ep s .. 
is  prt"virl ed  wi th  small  st ens  flb"ut  8  inches  squllre                t  ply  4  ft. 
6  in.  frnm  the  tt"lp't"If  the  wall.           sht"ws           wall  rt"sd        
which  fs"'prt"videc  With  (l  fire  step.  It .is  e'-nsidered  thnt  many  t"If  these 
st eps  hflv'p  prt"lbatly  t"nly  a  limit ed  use,  such  P..S  tt"  nllf'w  guards  a.nd 
sentries  t"bservatil"n  nver  the  wa11.  The  t"Iverhnng  "f  the  wall  eriC  the 
barhF'c  wire  aprt"n  fenc  "'ver  the  pnveroF'nt  in  frt"lnt          be  nf'lted.. 
(h)  Dykes 
"!'J.1&\  1':1                             
            ).                                  . "  i  ' 
1             it,                         "f  /"bstructing  rnrops,          up  tn  the  tf'lP  t"f  a  dyke  is 
.U ",:,,: u                     '1te  11.  Fflr  the  suke  I"f  clari t:r7  8  bflrbed':'"wire  fene t, 
,  which  is  sitcd  i::1  frt"lnt  flf  the  onncrete  wall.  is  t"mitted.  The  pit  is 
[1pl"rl"XimRt ell."  ::"9  f+,.  6, in.  x  10  ft.  x  6  ft.  6  in.  ana  bphind  it  1.  S  [-l 
crncrete  woll  dcr,"ss  the  entire  width  t"If  the  ramp.  It  has  been  estimated 
that  the  wall  :s  rDt"Iut  6  ft.  6  in.  high  x      ft,  thick.  Behino  this  wall 
there  are  3     4  rf'lws     inclined  steel                   rt"lws     steel 
       are        t"In  the  sketch. 
?..  DRb.GuNS  TEETH 
Plate  12,  figo  1,        a  IIdrt1g"ns  teethll             which  hD.s  been  repl"rted 
frnm  France.  The  teeth  incrense  in  height  fr"m        tt"l  reE1r  Dnd  0.11  have  (\  c"mmf'ln 
crncrete               
Anltther  tyPe  nf  drr.&('Ins  teeth  f'lbstA.cle  cl"nsi sting of 3  rf"WS  f'lf  15  triHngu-
Irr  pyramids  "f  reinf"rced           has  oFen            alsl"  frt"m  France.  The 
"pyramids,  rnf:     which  is  illllstreted  at  Plate  12  fig.  2,  have  a  ring  at  the  apex 
'and  "ne  abf'lut  helf-way  up  each  edge,  thrl'ugh  whieh  chains  may  be  passed.  Plate  13 
is  a  phr.tflgrFph     this  type      nbstacle.  j")lo.ts  14  shl"ws,  a  rnnd  gap  thrl"ugh  (I. 
cragl"ns  teeth  f'll:stacle.  rrt"visil"n  tn  bl"ck  the  gap  c"nsists  "f a  c"ncrrte  struc-
ture  slnttec.  tl"  take          gfrd,-rs,  placed  "n  each  side  "f  the  T('IaO,  This  t"o'Stncle 
is  knl"wn  tf'l  exist  in  Germany. 
3.  uCTAH:EIDRA 
   rE:pt"rt  fr"m  France  describes  an  "bstacle  which  c"nsists  f'lf  f'lct.ahedrr'l 
cl"ncrete blf'cks. 
4.  CuNCRET:m  RtlLLERS  u;"r  AIRFIELDS. 
\  '.  -.. -----
It  is  repl"rted  thHt  thE"  Germans.  s('metimes  use          crncrete           
ff'lr  f'lbstructing  airfields.        15.  figs.  1,  2  and  3,  shf'lws  three  sketch  views    
[!  r"ller,  which  is                    4  ft.  6  in.  in  dinmcter  x  2  ft.  in  width.  '.:'he 
cl"ncret'e  is  ap11r
r
ximatel:v  2t  inches'thick.  The  Tt"IlJ  t?r  i,s  mao.e_  in  tW('l  halves  and 
b,..ltec1  trgetr"er.  An  ir('ln  bpr  -pases  thr('lugh  the  centre  {'no  PTf'ltrudes  abl"ut  1  ft. 
3  in.  f'ln  Pilch  sioe  rof  the  rr'lller,  and  tr_is  is  used  tl"  fix  the'  r('ller  tf'  the  grf'und 
when  the  rbstacle  is  in  olace.  It  is  rept"rte(I  th[lt       c"ncrcte  was  made  'tli th 
shf'lre  gravE-l  and  cement.  ana  that  it  we.s  reinfnrced,  with  wire  netting. 
5.  uBSTACLE  GUARDING  BRIDGE  EXITS 
-Illustrcted  at  ..... late  16  is  a  c"ncrete  ann  timber  tvpp  "f          blf'ck  which. 
tt  is  stated,.  may  be  ff'lund  Dt  bridge  exits,  The  fixed  r}f'rtirn  is  bu1_1t  up  "f 
vertical  vibrnteo  c"'ncrete  "Tn  beams  nf  Fpnrl"x.  X  7*  Y  2  ip.  Orr-ss  sectirn. 
These            8  ft.  2  in.  If'lng  ana  pre  buried  3  ft.  3  in.  intr  the  grr'luno,  They 
are  placeo  in  pairs  apprt'ximntely  2  ft.  apFrt  and  3,ft.  3  in,  bet1JTeen  pa1.rs .. 
Similr r  itT"  beams  are  laid  ht"ri zt"lntolly  between  the  vertical  'beams  and  all  int (r-
stioos  filled  up  with           
The  bl"ck  is  cl"sed  by  means  ("If  16  in.  seu[-re  timber          sliding  intf'l 
reinf"'rcec  c"ncretc  anr         In  these  end  pt"lsts  the  sides  ('If  the  slides  r:re 
r;,dniti"nf'lllv  reinff'rcec.  by  vortice.l  steel  jrists: 
The  timber  baulks  fire  estimated  tt'  weigh  900  Ib's  t"r  m"re.  Timber  bnulks 
-f  this  size  pre  always  [:  clu.."1s;T  article  tr'l  handie,  ann"  in  this  instr,nce,  much  :unre 
difficult  t"  tFlke  "ut        tt"  'Put  in  !)f'lsiti"n. 
- 3  -
 
fO
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Oct  43  IWW 
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Ti!lmped  dry-mix  cone-rete.   
6101bs.  if             cubic 
yo rd  of  fini.shed  concrete  -. 
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.. ;,:.:,.. ' 
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. . '  ..... 
. -- . 
.        
..;  . 0, 
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Lo.n9itudinal. 
'eln  force mtlnt 
Jt;;  d;8m  . 
c 
0- 
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      ..
r  .... ' 
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 GO _  ..   
I  .. -"  .  '.!"'-. 
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.. f 
" 
c 
0\ 
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, 
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,/;"  t/J  b.,.s.         long 
-4  off  Pt/,.  metre  run 
ENEMY 
QURNTITY  PER  METRE 
RUN  OF  WRLL 
CONCRETE  MI)( -7-' m? 
                     
SeRLE.     
[ 
GERMRN  RNTI- TRNK  WflLL 
 
D 
 
m 
N 
.   -   ~   -   ~   .   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   ,   
PLATe  -3. 
FIG. I. 
FIG.2. 
GERMAN  USE  Of  Gl RDER5  TO  CLOSE 
GAPS  IN  WALLS 
I 
, 
l 
~ I / 
~ 
<  .... 
Rood  .1 
'*-4f /III., 
FIG. I. 
FIG.2.. 
Road 
Block 
TYPES  OF  GERMAN  ROAD  BLOCKS 
~ ~ ~ I ~  ~ ~ " - - - - - - - - - - - - - - - - - - - ~ 
PLATE  6. 
I ~  .. 
764 
9  l:J2. 
~  ~ 
, 
~ ~  I 
, 
()t 
\ 
I 
1-0  I  / ....  2.  I 
-...  ... - ., .. 
.3  -10 
~  . ~ 
I 
" 
,  If  ,  .,  , 
'f 
, 
I .. 
GERMAN  RAILW,qy  .sLEEPER 
''0 
 
.....
f-.  6' - '0'  _I 
   
,  ,0 
Tomped  dry:"mi"x 
concrete 
.,' 
, 
, 
,       
      
,  ,0. 
c: 0 ......
 
   
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" . 
-,  :if' , 
. :' 
  
 
" 
, 
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o 
... 
, 
 
a 
" 
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N 
DIRECTION  OF  I1TTnCK 
 
If) 
.   til 
/I"? 
-.  /"'#,. .. 
Dft!f'th  of                 drzpC2ndrmt  ,.' 
on  ground  wdter        tJ  lJf'(I          ,.1
,  ..  
,,\ 
,I" 
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    ,', 
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I"  5'--':'..          ."  J 
1_  7-.3  _  26-3 
tV I. 10.b/tJ97 
Oct.  4j  IJtJW. 
I  - I 
GERMf:JN  (lNTJ- Tf:lNK  DITCH  WITH  CONCRETE  WIILL 
1) 
r 
D 
-i 
rn 
--.J 
. 
PL.ATE  6. 
I  I 
I.  6"7
Q 
.. f 
I  I 
:  t 
I  I 
1  I 
I  I 
,  J 
I 
I  j 
I  I 
!  I 
- - - - - - - - - - ~ 
FIG.I. 
F1G.2.  F1G.3. 
GERMAN  REiNFORCED  CONCRETE  WALL5 
~ 
V) 
~ 
li: 
PL..QTE  '0. 
\ 
\ 
\ 
0.. 
UJ 
I-
U) 
I 
UJ 
n! 
lL 
I 
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~ 
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0 
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0 
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~ 
---1 
....J 
~ 
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<I 
~ 
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lU 
l!J 
ALL  L  /<7/7/'  7  '\  5Iee/.J
0
/
sls 
Concrele  IA/'Q// 
-
---   ----
" 
1_- _____ _ 
GERtv1t:lN  METHOD  OF  OB5TRUCTl NG  DYKE  RAMP3 
'U 
r 
D 
~ 
III 
PLATE  I ~ . 
FIG.  I. 
FlG.'2. 
GERMAN  DRAGON5'  TEETH  OBSTACLE 5 
('(1.t .107..8 9481 
PE.F. Dec.'43 
PLATE  I ~ . 
FiG. I. 
FIG.'2. 
GERfYJAN  DRAGON5'  TEETH  OBSTACLE ~ 
PLATE  I ~ . 
FIG. I. 
FIG.2.  FIG.3. 
GERtY/RN  MOVABLE  AIRFIELD  OBSTACLE 
(CONCRETE  ROLLER) 
r   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   -   ~   -   -      ~   -      -         ~   -   -
/  PL.ATE  16. 
l 
Of  RI()GE. 
UNREIN FORCE,() _   =   =   =   ~   ~   ~   
CONCRET'E 
CiROI/NO  LE.VSL 
SE.C TION  R  ...,.8 
... 
... 
.  , 
;. 
REINFORCE.{)  CONCRE TE. 
NJI.  10 b/887 
(Jt'!-.  4J  IJIti 
CONCRETE  rJ- Tk..  ROllO  8LOCK. 
1 .  m  ClI!UTET . 
DEttl 
,m ,f. -ASS/FlEiJ 
!.t  . is              that  d.u ring  a  reoent  tri al  in  Franc e .  a  TI"ad  bl('ck  O'''n-
st ati ng.  au ' ,arently . ... fI  a  Tnw  ... f  l ':l ements  C  flu,d  in -C" nerete  WBe  kn"' cked 
dl"WTl           by    t ank  .  Alth"'ugh  t.he  e.T.I)ressil"n  ukn"cked  dl"WIl' easilyll  1e 
'Pr"' 1:>ably             it mav  ... e11  be  an  InC11c{'til"n  that  the  I"bstacle  liI f: S  de-
_feated  11)  s"me  -.mv . 
Tn  a n,.t hpr  :pArt  ('If  Trance  1 t  1,s  l"ep,.rted  that  l""ad e  running  thrr ugh 
g8'D S  in  A.  tk.  d'itche s  e r e  bl l"cke(l  a t  night  by  !:lement s  C.  These  c"' uld .  r f 
crurse,  a ls'"  pe  used  t,.  blf'Ck  the  -!'I"ad  in  emergenoy . 
T'late  17         de  C" intet  " bntacl es  US9Q  in  c"njunetlf'n  wi th  steel 
hed geh"gs  {"1'  t V'eking  the  st>r,rr-8c:hes  t,.  a  r ailway  level  cl"" 3sing .  A  f eatun 
rf  the  I"b s t acl e  l11ustrDt'pd  1s  th(!t  a          o" st  eo" ut  3  ft .  3  i n.  high  is 
u s ed  a s  a  piv ....  t , ao"ut  ..... hich  the  ... h s.tncle  e Rn  b6  swung  f ....  r  fl p cni n&  " r  cIf"sing 
the  gal) .  Thp.  de  C"ln"t et.                in  this  case  arc . aid  t ...  bE"!  c"nstructl'!n  ro t 
8  mm.           anglo  8f'cti"ne . 
The  tetrahedra  erect ed'  at  the  sid, ' "r  thn  r"ac  in  the.            iUus":' 
tratt"d  at          17  a r e  said  t'"  be  cr-nstructed  f rrot1  5  mm,  thiek  channel 
s p. ctlr>ns,  weldprl  tf" g(> t l).er.  and  sunk  int'"  tbe  grrund  "'r  int-'"'  c"ncrr t e  t;"  the 
dB'pth  rof  ab"' ut  10  in  .  The  gl r dc- r:;  r r('                     3  ft.  3  in .  If'ng,  Sf' 
thE't  thp  -pyramin  has  a  v crtic a l  .. hpi ght  fl"'"Iil  th('  gr"und'  "f  B'Pt".r"x!.matcly  '2  fto 
Plate>     sh,.. .... s  an  -'"':b atacle  ..... h ich  c "'nslsts  ,..f  a  cr nthmo"ns  line  -'"'f  steel 
t(>trr:hf'crfl  sited  "n      t"'p. "'f  n  13en  wall .  The  hos es  ,.. f  tho  t ctrchf'd r a  a rc 
j -'"' lnrd  t "' g("t hC'r  by  st pol  chennds "  thus  i nCrE'Dsing  thE'  efficacy  .. f  the 
         
3.  HEDGEHvGS 
P  .   tk                  rp.  11  beach  in  (luern s<'y      add  t,.  be  heavy.  requiring 
r'ur !!len  t,..  m"v'c  them.  " The  Crl"lIi3  membC'rs  ere  made  -'"'f  engl e  i r "nsE\llc the 
f ef' t  ... r  thp  "' 'bstaele  fi re  j"ined             by  stefll  ehennf;l  E"mbcilced  in  c-'"'ncreta. 
4 .  RvLLED  STEF--L  J u!STS. 
:. t  is  r e'P"' r tcd  thpt  the  maln  re frmen  Ar  a  T"wn  in  Nl" r thern  France  c"'n-
s1 st  ,.,f  a  series  ...  f          S:t ccl  ,1"1 st s  fixl' d  in  the  grl"' und  enil  sl<"pi ng  t('l .... 
werCs  the        I"t  an  angle  -'"' f  60
1
' .   (J"'la t f>  19)  .  Tw ....  thrc.f!. " r  -r"ur  such  j l"h"" c 
ere  us'"  acc-'"'ril.ing     thC'!  wi dth  ""r  thE'  atrC'ct .               rails  are  fi t tPd 
in  the  sl"ts  mar,o  by  thC'  pai r s  rf  j,.i s ts ,  t hus  strcngthcm1 ng  the  barri er. 
='l l! t es  20  and  2;1..  sh ........  strcf! t  ...           c!" nsi stlng  ,.f  incl1npd  r ails. 
Plat e  21  shr ..... s  an  "'bst ecl e       R  gcp          r p.s trict ed           and  in 
t he             ce..n  be       s '  de. Cdnt'ct  ... bstacle  r eads  V         the  gap  i n 
emor gency,'  The.  gal>  r.h"' "W!l.                  -ph!'t r  ir,  c-'"'mr'll ,..,tciv  cl"' !"t' c'I  .  by.i n-
oli ned  R. S. J, ,. 
An-'"'thC'r  anti-t ank  I'bstncle  cf"vering  s  rl' ed  1e  rC'';')t' rt ('c  as  being  Ct'IOPl"Sed 
I"f  twr>  l"f'WS  rof  s.tc(l.l  r e. lIs  the  r"':01"5  bC'1ng  3pp rl"xlmetcly  3  ft.  apE' rt  and  tht:' 
distanc e  betweC'D  r ei l s  1  ft .  6  in,  lnn  2  ft.  The  r n1!s  a r e  fi xf'c1  in  t he 
p av C'm('>nt  and  r em-'"'v rabl e  in  the  c a :rriage  way.  F"'r                    sne  :'la t p.  32 
of  n"tcs  on  Gormen  obstaclos fi{tlASSlflEO 
PART  IV    DITOHES 
.( 
1 Wi .,                    ,::             lW;" 
:J                              anti-tank  ditch  in  c"utse  "f c"nstrueUI'n.  The 
revetnent  in  this  'case              t('l"  be  fit  e('lnc'rete.  :Plate  23  shl"lWs  anf'thel"  ditch 
tIl:  which  the  :stdes          t'K  be revetted  wi th  wattles  t"r  brushwl"lt"d
l 
The 
pnf'\t"grar;h        tf'f',  thet  -the  sll\pe  f'f  the  sides     this  d1 teh  are  prnbably 
less  than'SO  'which  l'ends  ol"lll"lur  tf'"  repflrts  that  it 'had  been  orflssed  during 
tests  while  the  ditch  was  dry.  The  depth  1"1  water  in  the  diteh  has  been  given 
as  9  ft.  9  in.  ane  the          the  water  surfaoe  45  ft. 
0thet- water-filled.  dttches  f'lf  this  type  have  been  repl"lrted  as  having  the 
     t"wing  dl:mensit'ns1-" 
Width  (T,..p) 
       (Bf'ttf\Dl) 
Depth 
Depth  rtf  water 
 
50  ....  80  ft. 
33  ft. 
10  ft.  - 11  ft.  Sin. 
6  ft.  6  in.  - 8     
An  anti-tank  ditch         a  defile  between      hills               
France.  The  a1toh  dt'les      ct'ver  the  whflle  defile  a  gap  tn  f"\ne  sid,s  being 
blneked  by  ennerete  pillars        4  ft..  11  in,  thick. 
2 ,  TANl  TRAPS 
         fig.  1        onnstruetinnal  details  flf  a  type     anti-tank  ttap 
which  has  been  rept'lrted  as  onvering  the             in between  sand  dunes  nn  the 
cnast  f\f  Eurnpe,  The  trap  is              in  brick  in  such  a  way  that,  altht'ugh 
it  wf'ulCl  allow  light  traffic  tt'l  pass,  it  wf'ulc1  cf'llapse  under  a  heavy  l('\ad. 
Ant"ther  t'rpe  nf  trt\P.  built  nn  a  beach  and  sited  in  frf'nt.  f\!  a  sea  wall.  is 
illustrated  at        24,       2, 
Twf'           anti-tank  ditches  aTe  illustrated  at  Plates  25  and  26.  Nt'! 
oetails  are  at  nresent  available  flf  the  Duality  flf  C'(\nerete  specified  fnr  the 
retaining  walls.  nf\r  t'lf  the         flf  reinft'lrcementt  nf'r  of  the  type  ('\ 
material  used  ft'r  the  thin  vaulting.  Ht'lwever.  a  rept'lrt  states  that  the  vaul-
ting  is      briok  thiok  and  that  it  will             a       of  appr('\x1mately  660 
Ibs. 
3,                    
It         be  renenbered       in  the  Lnw  C(\untries  in           to  the 
ditches  dug  by  the  Germans,  the             eanals  form  in  themselves       
tank             In  Sf'me  cases      Germans  have  repaired  the  banks  and  deepened 
the  canals. 
4.  "OHIOANE"  DITCHES 
An(lther  type  ,.,f  I1chieane
tl 
         is  illustrated  at  plat e  27,  It 
         t'lf  tWf't  ditches                20  ft!  Inng  and  10  ft.        built  nn 
np"pl"lsi te  aides  t'f  the  %'f'Iad,  the, secf'nd  ditch  being  ..st'me  30  ft.  further  dl'Wrl 
the  road  tr(lffi  the  first,  The  ditches  are  c(lvered  by  planks  and  it  is  repnrted 
that  therp  hav6  already  been  accidents  tn          
                -- -- -- -- -- __ 
         - - - -- -- -- -1-1  ---------_____  __ 
De Co/'lfef 
DhsIZu:ltfl.3 
w ,  ,                     
Conr:;rele .:surFace 
with SO  /i!!t;.,/hedra 
""3'.1 sie:S1     
16            
""-,,L 
  x x,. x x 
Road 
De Co/nlir!r ah.s/QCk3 
GERMAN  METHOD  OF  OBSTRUCT' NG  LEVEL  CR05S( NG5 
Ir: ...  ..-.. ......,.;:'6. .......  .."  I 
"tl 
r 
D 
-( 
III 
-J 
 
PLATE ..  19 .. 
LU 
---1 
i 
u 
~ 
~ 
~ 
~ 
\0 
d} 
~ 
0 
IJ 
~ 
~ 
r-
CI 
. 
J 
iii 
 
OC 
lU 
-1 
dJ 
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0 
a 
I-
#9,,3 
r. 
cr 
~ 
~ 
lU 
19 
                                                                                                                                       
.5ea 
II( 
                                                                                           
   
, 
   
11) 
F 
Sand 
Sea  Wall 
FIG.2. 
GERMAN  ANTI-TANK  TRAP.5 
1:
Ii 
 
 
.1 
 
 
 
. , 
..... 
PLATE  'Z,5. 
I'" 
     
  
' .  
 
cr,) 
.. I 
.... 
\ 
SE.CTION  IJ-IJ  \ 
.seRLE    
EQUJ:lL  SUPPORTS 
1111
1.J 
I 
I' 
 
I 
I, 
, 
I, 
'I 
1/
I, 
II 
II 
I 
I, 
'I 
II 
I, 
  II 
   
'I 
UIJ 
II 
II 
-'- IJ
\ 
\ 
\If 
'co 
.r 
f'/ 
 
V) 
,  r 
 
., 
... 
" 
Cc)
I 
 
.q;l 
 I 
 
I 4.'- II"  I  1/' - ::<..," 
: 
,....  -
_  ..2::o!'-IO" 
/ 
/ 
\1
I; 
 
U 
1\
II 
1\
IJ
II 
II 
A 
+ 
I 
I 
I 
I 
I 
I 
I 
I 
; 
I  I  :0 
    
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....L 
illS 
 
'I 
T 
II 
:1
','  . 
   
..   til  0  ,  . 
  """ ...  ..   .   : 
' .. 
.    Q .. 
.t.' 
,  '  . 
-.  ..;  ....
PLRN 
SeRLE.      
GERMRN  COVERED            DITCJ.I 
" 
...1 
PLATE     
,  -I--
: .'.1./.      , 
                                                 
,  .. 
        , 
-r  Ii  S'- II" 
SECTION  R-/=I 
seRLE       
UNE.QURL  SUPPORTS 
o  A 
 
t 
I 
  
Irr 
II 
'I 
II 
 
ru 
II 
" 
. , 
 
,   
" 
II 
I' 
,I 
II 
II 
"  I' 
, 
I' 
V, 
I' 
..  t 
II 
! 
,I 
I' 
" 
I 
'I 
" 
II 
-! 
" 
:' 
II 
II 
[11- --
I---
II 
It 
I' 
:c
II 
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II  I 
I, 
 
'I 
:1 
,I 
" 
    ,  II 
. ,. 
" 
VII 
'Oar 
(It 
I, 
.- W 
1
4
'-11'  I 
:  ... 
I 
II 
14
II 
     
l..r  'I 
'I 
I, 
I, 
" 
I, 
Ii 
'I 
II 
II 
II 
I, 
I, 
'I 
" 
I, 
II 
" 
I, 
II 
'I 
It 
I 
..  ---
- -
II 
II 
I' 
I 
'I 
II 
II 
II 
II 
I, 
II 
" 
.  ; 
I,  o  ;.. 
f1+l+; 
  
,  '1 
if 
I 
" 
I, 
II 
I'-d"  ,: I ' ';)!..  ,,"  I 
'  6"  :  /8  - __ 
\ 
\ 
"-
t 
_J 
'0 
, 
ExpanSion  loin/:. 
PLflN 
SCRLE.  -;'00 
GERM liN 
COVERE::O  RNTI- TRNK  DITCH 
Pard_  25 
PLATE  27. 
A--t,..-;.---
~ 
SECTION  AB 
GERMAN  "CHICANE"  DtTCHES 
Thp  pviclence  avvilable  I"n  the  ft'l]l"Iwing  is  such  thvt                    
sh"u1(,  "'nl:r  'be  cl"nsiclered as  nnr,,'bables". 
1'1  mIDERWATER  WIRE 
Uneerwater  wire  I"bstacles  hDve  been                twl"  places  "'n  the 
]elgian  CF'ltst.  The  first.  in  frl"lnt  i"f  n  strF'lngpl"\int,  crnsists' 1"1  three 
bf:roec..  wire  fences.  "'ne  [It  ll"w  woter,  i"ne  at  hnlf  t1r.e  anf!  I"ne  just          
high  wvter.  W",.,den  pickets  have  been  userl  fl"r  011  three  fences.  Anf'ther 
"brr":,en  wire  fence  in  tl  different, ll"crlity  is 'repf'rt  as  beinf-'  sl"me  50        
fr('lm  the  nrf'lmennde.  Parts  1"\  this  fence  f're  uncLor  we.ter  nt  high  tiff:, 
2.  OONCiETE           
A         tf'l          bnrbed  wire  entnnglements  rencered  ineffective  oy 
drifting  sRnd  has  been  repf'lrted  frl"lD  the  S"uth  rf             is  stnter  thnt 
S"P.le  tine  flgf'  the  {J.T.  were  arrnnging  ft"r  cl"ncrete  bl('cks  suppl"rt  irf'ln 
rnils  ti"  be  pInced  F"In  beaches  just  belf'lw  high-wnter  !'lnrk.  These  w(\ulCl  n,.,t 
I"\nly  fnro     I"Ibstacle     trri"ps  in  the  event     D  landing  further       the 
'beachy  but  w(\ulc  alsr'          lElnt:'ling  craft  if  they  atterrpted  landings  EJt 
     tide. 
An"ther  re'P"rt  states  thDt  cl"ncrete  piles  have  been  driven  intf"  the  sea 
bee  pbl"ut  100  yds
l 
belt"w  high  \v8,ter  !!w.rk  in  a  l(\oali tv  in  N"rth  France.  The 
niles  Fre  spir  tf'  f"rm  a  belt  sl"oe  20  YCTC.B  "l1c.c  'wi th  3  ft.  intervrls  'Je  .... 
tween  them. 
l").lffiT  VI  - MISOELL@EvtTS 
1.  CtJlf.;'luUND  vBSThCLES 
While  the  m.aj I" ri ty  f"f  r.bstacles  ct"nsist  f'r  a  oain                 6upn"rted 
perilP'P
s 
1,y  f"ne  1"1'  tWf"  subsicHaries,  (\ne  re1.1(\rt  illustl'ptes  the  cr.nstructif'ln 
("'If  seve-rrI  rr.ws  !"If  alE1"'st  cauE,Il
v 
iT.1u'rt8.nt  Dflrriers.  This  f'bstacle  Cf'lIr.-
prisee,  in  successive  r"wa.  a  baropd'wire  fence.  severfll  r(\ws  (\f  crncrete 
cr.sts,  a          an  anti-tank  wall       finally,  anflthpr  barbecl  wire  fence 
and  is  illustrated  at  ;'lrte  28.  It  will  be  nf'ted  that  the  whl"lle  r.1)stacle 
is  Dnr'e  P.lf"re  fl"\rmic.:Jable  by        siteo.  "n  a  ff'rwarC'  slf\pe. 
2,  SWING           
Plate  29  sh"ws  en  irr.n  "'Jar1'i or  which  i s         acr(\ ss  the  rt'src  (,D('  If'lckec. 
tf'  anf'ther  rst  "n the  I"IpnC"site  side  f"f  the  rf'ad.  The  cr("ss  l)ar  C('Ii.n  rises 
a  heavy  irf'n  pflle  with  a  sharp  tf"rthed  serrati"n  al"ng  its  t"rJ  edge. 
3.  ANTI-AIECRAFT           0BSTACLES 
   has  been  rcp(\rter.  that  all  flat  surfaces  near  D.  rrench  P(,:r"t 
(exclucing  areas  "f' water)  are  cflvered  with  anti-aircraft                    
These  Cf'm:  rise  n  c"ntinuC"us  netw("rk  I"\f  steel  c[D1es             fin  10  in.  tieD. 
steel  tu1)es  at  a  height  ('\f  abf'ut  20-25  ft.  The  ca1Jles  are  attHcher- tl" 
wI"'f'lc,en               blf'lcks  which  fit  intfl  the  steel  tubes. 
DEC LASSI FI ED 
        ZO 
Barbed  wilYl  knn/l 
'./  .0."'"   
(I  :      .,'  .0  Rnti- Tonk  wall 
',.      _/ 
"   
IJ  '\  "'.&  D, 
t   .,  .'. 
. ,"" 
II 
8orbl?d  wire>  fence 
\ 
GERMAN  COMPOUN D  OB:>TACLE 
I 
i 
                                                     
GERMAN  SWJ NG  BRRRI ER  OB5TOCLE 
COpy       
            
./ 
U1\mERWATER  OBSTACLES 
1.  Evidence  concerning  underwater  obstacles  on  the  coasts  of  France,  Belg:iu.rn 
and  Holland  is  slight.           it  is  likely  that  the  Germans  have  experi-
mented  with  certain  types  of  underwater  obstacle,  there  is  no  reason  to 
believe  that  any  of  these  has  been  adopted  and  laio.  down  extensively;  confirm-
ed.  instances  of  underwater  obstacles  in  posit i.on  to  date  are  few  and.  in  them-
selves  relatively  unimportant. 
The  chief  reason  for  NOT  using  underwater  obstacles  on  the  coast  of 
Western  Europe  is  the  difficulty  of              them  'over  a  long  period, 
especially  in  the  winter  months.  This  difficulty  proved  overwhelming  on  our 
own  CI:WHrEL  coast  in  1940,  1941:  some  steel  obstacles  remained  effective 
in  SUJnIneT  but  even  the se  were  quickly" destroyed  by  the  first  winter  -storms. 
On  these  grounds  it  is  likely  that  the  Germans  would  delay  laying  clown  any 
obstacle  they  might  select  as  long  as  possible. 
2.  The  following  is  a  resume  of  the  most  iITlporta,nt'  reports  so  far  received  . 
(a)  Wire 
Underwater  wire  has  been  reported  on  several  areas.  In  some  cases 
it  is  certain  that  these  reuorts'were  incorrect.  Only  one  instance  has 
been  verified      air  photographs.  This  is  at  COXYDE  in  Belgium,  where  in 
summer  1943' an  oblique  sortie  showe"d  several  irreguJ.ar  stretches  of  low 
     entanglement  or  fence  on  the  beach  well  below  high  water  mark.  The 
obstacle  was  NOT  continuous;  the  sections  'seen  on  the  photographs  ap-
peared  to  be  generally  parrallel  to  the'  line  of  the  coast.  Such  wire 
in  water  between  knee  and  waist  deep  might  form  a  serious  obstacle  to 
invading           
There  have  been  one  or  two  reports  of  waterproof  mines  laid  on 
beaches  in  Holland  below  high  water  mark.  These          are  ent 
unconfiTmed,  and  no  great  imnortance  is  attached  to  them.  There  is,  on 
the  contrary,  some  negative  reason  for  believing  that  at  least  U'i)  to 
summer  1943.the  use  of  these  in  the  West  was  not  envisaged. 
(c)  Concrete         or  pillars 
Indications  of  these  are  very  few  and  vague.  Their  presence  wuulQ 
certainly  have  been  revealed  by  air photographs. 
(d)  Steel  Obstacles 
A  number  of  reports  on  underwater  obstacles  concern  various  types  of 
steel  obstacle, 
(i)  At  QUIJEVILLE.  on  the  East  Coast  of' the  COT:SlTTE,T 
trials                     were  repor-ted  in  the 
of  1943.  0    of  more  recent  date  mentions  p, 
tetrahedro  j  t,  .           ined  with  fixed  flame  throwers. 
Oblique  'Photog'  .        Hay  and  July  reveal. 
(a)  a  single     ',9!    . trahedra  on               
front  of  an  infantr..             of  till.S  IJ.ne  lS 
several  yards  below  hig       Jr;.  It  is  an               
obstacle,  1Jt.1,(  , 
(if,;" 
- I  -
       it  is  possible  that.  as  claimed  in  the  above-
ment ioned  rep9rt, . fixed.        throwers  are  installed  in. 
this  obstacle    this  Gan  NOT  be  confirmBd.  from  photogra!--,hs. 
(b)  I  in  front  of  Q,TJ:r11EVILLE  village,  a  few  sections  of 
German  curved  eteel  rail  obstacle,  at  various  levels  on 
the  beach.  The  longest  stretch 'consists  only  of  about 
six.1l!lit.s
p 
It  is .possible  that  these  units  were  placed 
on  the  beach  in  the  underwater  obstacle  tests  mentiolled 
above.  None  of  the         on  the  photographs  is,  in  its 
state  at  the  time  of  photographing,  extensive  enough  to 
form  a  serious  obstacle;  and  if  curved- rail  had  heen 
adopted  as  an  underwater  obstacle  in       area,  more 
reoent  sorties  would  certainly  have  revealed  its presence. 
As  an  argument  against  the  QUHmVIL1E  curved  rails  being 
intended  as  an  underwater  obstacle,  it  should  be  noteci 
that  continuous'  lines  of  curved  rail  are  commonly       
at  the  back  of  beaches  in  this' area,  above  high  water 
mark,     an  anti-tank  obstacle. 
(ii)  A  report  emanating  from  a  reliable  source,  but  so  far 
unconfirmed,  states  that  staggered  lines  of  Elements  Cabout 
40  yards  apart  have  been  set  up  on  the  beach  at  the  BAlE  DE 
KEPBIC
t 
near  PLOUESCAT  in  North  Brittany.  At  high  tide  they 
are  said  to  emerge  2  - 3  feet  above  water.  These  would  of 
course  form  an  obstacle  to  landing  craft.  At  the  srune  time  it 
may  be  noted  that  various  types  of  steel  obstacle  anr1  in  acl-
dition  scrapped  motor  vehicles  have  been  reported  on  the  LIEUE 
DE  GP,-"EVE.  also'  in  North                    'as  an  obstacle  to  aircraft 
landing  on  the  flat  beaches  in  this  area. 
This  is  the  only  serious  indication  of            C being  used 
as  an  underwat'er  obstacle  ,a.nywhere  in  the        
(iii)  Vertical  steel  rails  have  occasionally  been'  mentioned  as  en 
under\\Fater  obstacle,  for  examule  at  ST.  1l.1AIJO  "  ani  the.
1
:,e  'is 
some  indecisive  evidence  that  such  an  obstacle  was  encountered 
but  easily  overcome  by           craft  at  DIEPPE.  on  the  basis 
of  present  information.  little  weight  can  be  placed  on  these 
report s. 
In  general,  it  may  be  said  that,  although  the  Germans  may 
have  tested.  V"arious  types  o:f  steel  obstacles' below  high  water  mark,  they 
have  NOT  laid  them  c.own  extensively  anywhere  except  perhaps  on  a  few 
B?ETON  beaches.  On  the  CHANNEL  and  NORTH  SEA  coasts  the  presence  of  such 
obstacles  would  almost  certainly  be  known  either  from  ground  sources  or 
air  photographs '. 
(e)  NaV"al  Mines 
There  is  no  evidence  that  the  use  of  naval  mines  in  shallow  water  has 
been  tested  or  is  envisaged. 
3.  On  the  possibility  of  the  Germans  laying  unde.rwater  obstacles  in  the 
period  immediately  preceding  an  invasion  there  is  no  concrete  evidence.  No 
such  intention  has  so  far  been  reported.  In  general,  it  would  be  possible  to 
lay  wire  or  mines  at  short  notice;  very  little  preparation  would  be  needed, 
and  enemy  intentions  in  this  matter  might  well  remain  unknown  up  to  the  last 
moment.  The  use  of  steel.  obstacles  and  concrete.  obstacles  would  require 
extensive  prepara.tions  and  the  accumulation  of  stocks;  preparations  would 
probably  be  reported  by  ground  sources,  and  air  uhotographs  woulQ  certainly 
- 2  -
reveal  the  actual  construction  of  the  obstacles  or      dumping  of  materials 
on  the  beaches.  The  use  of  naval 'mines  would  involve  the  accumulation  of 
stocks  and  the  presence  ofmine-laying  craft  in  ports  near  the  b.eaches 
affected;  while  the  mines  might  be       at  short  notice,  it  is  probable 
that  the  preparations  would  be  repoited  by  'ground  sources. 
I'Jf  >:.(,    -         , 
(i) 
       .!,  ;/1       m    
The  laying  of  the                     of  obstacles  under         wou.1Cl  be 
practical  from  a  technical  point  of  view .''CJ..  ,fl' ;/Jf 
(a) 
  The  standard  type  of  thick  wire                (i.e.  a 
combination  of  double  apron  and.  triple  concertina)  is  NOT 
likely  to  be  met  with  since  it  has  been  found  that  in  this 
     comparatively  light  surf  and  wave  action  will  uproot 
it  and  carry  it  up  the  beach  or  cover  it  with  sand.  The 
easiest  types  of  Wire  to  maintain  within  tidal  and  surf 
range  are  pig wire  fences  framed.  on  a  square  pattern  with 
external  aprons;  alternatively  single  rows  of  double  apron 
fence  erected  at  an  acute  angle  to  the  normal  direction  of 
the  Wave  front. 
Personal  trials  carried  out  by  Combined  Operations  Experime.ntal 
Establ ishment  indicrate  the  hopelessness  of  trying  to  wade  v:aist 
high  through  even  light  wire  obstacles  which  are  out  of  sight 
under  water.  Wire  thus  becomes  a.  serious  obstacle  when 
resting  in  depths  of  between  5  it  and  I  ft  6  ins.  If  deeper 
than  this,  L.C.A.  can  run  over  it;  if  shallower,  it  can  be 
dealt  with  by              infantry. 
(b)  Teller  mines  could  be  laid  anywhere  wi thin  tid.al 
range.  Owing  to  the  increased  risks  Of  sympathetic  detonation 
under  water  they  are  not  likely  to  be  spaced  closer  than.IO  ft 
between  mines  (T.42)  or  30  ft  (T.35).  The  mines  would  not 
of  course  affect  infantry  but  might  cause  a  high  percentage 
of  casualties  amongst  the  first  flight  of  vehicles  landed, 
Experiments  at  Combined  Operations  Experimental  Establishment 
appear  to  indicate  that  the  risk  of         to  landing  craft 
grounding  on  mines  is  small  ana,  can  be  accepted. 
(c)  Naval        Magnetic  or  acoustic  mines  which  can  rest  on  the 
bottom  could  be  laid  in  the  low  water  stretches.  Their 
effect  on  landing  craft  which  have  not  been  degaussed,  wiped. 
or  fitted  with  S.A.  gear  may  be  a  subject  for  consi'deration. 
(d)  Element  C  Could  be  place  below  H.W.  mark  and  could  be 
entangled  with  wire. 
(e)  Tetrahedra  curved  rails  or          framework  couldalso 
be  so  placed:  ' 
(ii)  Preparation  necessary  for  the  enemy  to  give  effect  to  such  measures 
would  be  as  follows: 
(a) 
(b) 
Wire  Very  little preparation  needed.  Could  be  erecteQ  at 
s1t>"rt ,1<TlO,tJce  at  the  rate  of  say  1000  yds  in  3  hours  provia.ed 
                  personnel  and  simple  engineer  stores  required 
        ..                        
  .  .Jr. J                 
Mines  Very 'li ti.le  p-rsparat ion ,,'Q.peder.  Could  be  laid  at 
short  notice  at  thtSra.te             ':'  '  ..  ccc  yds  in  3  hoUrs           
the  nece s sary  p ers onnel           ., . B  were  avai labl e  (of  mining 
of  beaches               Mines        only  be  likely  to  be 
laid  under  water  at  the'last  possible  moment
t 
since  they  do 
not  remain  watertight  indefintely  and  would  soon  shift  lmder 
surf  action. 
"Z 
u  -
(c)  Naval  Mines  Magnetic  or  acoustic  mines  would  be  laid  at  short 
notice  provided  that  the  craft  anr  mines  were  available .. 
.                                           ':.  t  It"  b  bl  h  h'  uld  bId . 
\!. .".       ',i'  ,;                  .   IS  ImprO  a  e  t  at  t  IS  wo  e  :p  ace  In 
   '-l    :,' .... .r.      ":.  ''''.  ..,.' 4             ( 
t         \                         t  the  last  moment . It  is  heavy  approx  tons 
                  ,  -.  10  ft) 'and  would  be  difficult  (though  not  impossible)  to  move 
over  a  sandy  beach.  Its  existence  could  be  ascertained  by 
aerial  photographs  prior  to  any  operation. 
(e)  Tetrahedra,  curved  steel  rails  or              framework  The 
same  applies  to  these  as  to  Element  C.  It  is  possible  that 
concrete  blocks  could  be  unloaded  from  barges  at  reasonably 
short  notice  but  such  a  project  should  become  known  prior  to 
any  ousration. 
(iii)  The  evidence,  positive  or  negative,  of  such  preparatory  measures 
having  been  taken  by  the  .enemy  is  8.S  follows: 
(a) 
(b) 
(c) 
(d) 
Wire      large  dumps  are  kn,own  to  exist  near  beaches  but 
there  are  normal  engineer  dUmps  inland.  For  any  given 
landing  beach  the  quantities  required  are  relatively  small. 
Mines  No  large-dumps  are  known  to  exist  near  beaches  but 
stocks  are  known  to  be  held  at  the  ammunition  depots  inland. 
For  any  given  la.nding  beach  the  quantities  required  are  rela-
tively  small. 
The  Channel  ports  are  known  to  be  used  by  enemy 
mine  sweepers  and  stocks  of  mines  therefore  exist. 
Element  C  Uo  stocks  are  known  to  exist  either  near  beaches 
or             It  is  on  the  whole  unlikely  that  if  they  dia, 
exist  We  should  not  have  any  information  to  that  effect.  Its 
use  as  an  underwater  obstacles  is  therefore  unlikely,. 
(c)  Tetrahedra,  cur'Vec'.  steel  rails  or  scaffoldin,e:  framewQrk  The 
same  applies  to  these  as  to  Element  c. 
1.  A.P. D  C  , 
W.l. 
             
- 4  -
0160/2409 (Me 1.10) 
G  E  R  MAN'  FIE L  D  W 0  R  1':  S 
NOTES  NO.1. 
Contents:-
M.I.1C. 
The        Cffice, 
December,  1942 
Distribution  List  !tBt! 
Covered  Concrete               
     Emr:>lacements. 
Emplacements  in  caves. 
Brickwork  Emplacements. 
Concrete  Shelters  and  Command  ?osts. 
German       Wall,  1939. 
Copy  No  736 
,  ...... 
,  ""....  ... 
  
DECLASSIFIED 
There  have  been               of  the  use  of  steel  reinforcement  in 
the  construction  of  concrete  em'Olacements  in  ?ranoe,          and  Holland, 
particularly  in  concrete  areas. .  . 
Unfortunately  in  the  absence  of  reliable  re:)orts  on  weight  and  s:oacing 
of  the  steel  and  the  T)roT)ortions  of  aggregate,  sand  and  cement  used,  the 
quality  of  the  finished  concrete  is  unknown. 
(a)  :B'igs  1  and  2  are  sketches  of  a  type  of  M.G.  em:1lacement,  a  nwnber  of 
\\Thich  have  been  built  on  the  dunes  in  the  WAASEN,AA3.  district  of  Hollan'd. 
They  are  said  to  be  built  about  50  metres  apart. 
(b)  The  half-size  pillbox  (Blockhaus  6  :  Bh6)  101'  one  N.C.O.  and  5  men 
with  one  M.G.  takes  203  cubic  metres  of  concrete.  The  full-size  design 
\'Thich  )rovides  for  10  to  14  men,  normally  12  with  2  M.Gs.,  takes  250  cubic 
metres  of  concrete.  Plans  of  these  are  unfortunately  not  available. 
(c)  At  Fig.  3  is  a  sketch  IJlan  of  an  em:'llacement            from  the  area 
Horth-,\'lest  of  BREST.  The  siting  of  these  is  said  to  be  on  cliffs  and  head-
lands  at  intervals  of     3  miles  where  they  can  cover  most  of  the  bays 
and  creeks.  The  gun,  presumably  A.A.,  may  be  mounted  on  the  roof  of  thu 
ammuni tion  s tore   This  gun  :position  has  not        confirmed.  and' it  is 
          that  the  gun  has  a  separate  emplacement  nearby. 
Camouflage  is  in  the  form  of  garnished  nets,  turf  and  seaweed. 
(d)  A  type  of  reinforced'concrete                 )robably  designed  :to  accom-
modate  an  A.Tk.  gun  in  addition  to  L.M.G.  or  small  arms,  is  shown  at 
Fige.  4 and  5.  'Note  the  wide  field  of  fire  and  the  ends  of  the  concrete 
a:Jron  viall  bonded  into  the  cliff  face.  Along  the  a?Jron  the  roughly  coiled 
barbed  wi re  .appears  to
l 
be  a  Ii t     thin  i.n  :9laces. 
(e)  Fig.  6  is  a  sketch  j)lan          the  :?robable  lay-out  of  a  heavy  German 
gun  em:!lacement.  Figs.  7 and  g  are  0xternal  views  of  the  finished  construc-
tion.  Interesttng  external  features  are  the  elaborate  ventilation  funnel 
and  duct  which  may  be  either  in  concrete  or  steel  and  the  vertical  steel 
shield  which  covers  the  onening  around  t he  gun' tur.ret.  Thi s          is J 
            sup-uorted  by  the  steel  columns  and  joists  11hich  form  the  frame 
of  tho  structure.  This  shield  is  not  always  fitted. 
(f)  The  use  of  old  tanks  and  tank  turrets  in  combination  with  concrete 
for               is  widespread  in  the  coastal  districts  of  France  and 
Bolgium.  These  e1n:1Iaeements  are  chiefly  of  the  following  ty:pes. 
(i)  Tanks  with  M.G.  and  A.Tk.  guns  ,rotected'by  concrete  walls. 
(1i)  Tanks  buried  in  the  sand  and  camouflage            
(iii)  Tank  turrets  embedded  on  concrete  foundations  on  harbour 
moles  (Fig.  9). 
(iv)  Tank  gun  mountings  in  concretu  pillboxes. 
(y)  Tank  turrets  or  cu:polas  on  roofs  of  concreto .!)illboxes. 
(g)  Private  houses  in  coastal  districts  have  been  cOl1vI.rted  into  emplace-
ments  v/ithout  altering  the  external  ap?1eara,nco ,of  the  building.  Reports 
have  beun  received  that  somo  of  these            aI'S  connected           by 
underground  tunnels.  Although  no  technical  details  are  availabl'e  it  is 
          that  a  good  deal  of  this  work  has       done 'in  concrete .. 
         .;'  'fl:( .      :  t\ 
(h)  Small  em"nlacemronts.bave  boeri: sited:     (!JB-         and  flring  :Jositions 
have  also       constructed  by  buf,}.ding            thl;  f9.cO  of  sea  walls.  Figs. 
10  and  11  are  some                               ' 
/A 
- 1  -
A  type'  of  lVI.G.  em-f)lacement  is  shown  at  Fig.  12.  It  has  a  curved 
front  wall  wi th  loopholes  and  accommodation  is  -'Jrovtded  for  the  crew. 
The  s.ketches  giv8'  Gstimat'0d  internal                                                
is  from  80  cm"  (2  ft.  Tin.)  to  1  metre  (3  ft.  3                    "!::'."  '>,'"         li) 
   1.'i 'ii   ,;             \; .  ,'\;           
An  external  earth  covering  of  1  metre  vias           Fu'rthcr  accom-'  . 
modatiori      men  was  'constructed  5  metres' from  thG  gun  position. 
       EMPLACEMENTS. 
      gun  :?osi tions  have  been                as  follo\"ls:- Semi-circular 
'valls  20  cm.  (8  in.).  thick  built  on  a  circular  concrete  slab.  The  outside 
face  of  the  wall  r'  tains  a  bank  of  earth  or  s  nd.  Blast  and                
\'lalls  of           are  also  used  on  a  large  scale. 
Accordi,ng  to                                 the  follol"ving  are  the  a1)"f)rox-, 
imato  dimensions  of       emylacoments:-
(i)  7.5  em.  guns  - 20  ft.  diameter. 
(ii)  10.5  cm.  guns  - 25  - 35  ft.           
(iii)  15  cm.  guns  - 35  - 45  ft.  diameter  (older  'ositions  are          
about  30  - 35  ft.  diameter). 
(iv)  Heavier  guns  - 50  ft.  diameter  and  over. 
(v)  Railway  guns  - 75  and.95  ft.  diameter. 
EMPLACEl1EJTIlS  IN  CAVES. 
The  Germans  have  converted  caves  and  hollovlS  in      cliffs  in  various 
:'?arts  of  the  French  coast  into  gun  emplacements.  There  are  no  details  of 
the  engineer  work  involved  in  these  conversions  although  it  may  be  assumed 
that  a:tr)rcciable  quantities  of  concr(3te  have  been  used  in  the  work.  There 
is               evidence  that  entrances  to  caves  are  walled-up,  apparently 
\'1i th  concrete. 
BRICK1'10RK  EMPLACEMENTS. 
M.G.  IJosts  constructed  in.  brickwork  haVG  been r  e:'ort,od  in  the 
MIDDLLKERKE-\mSTEl'JDE  area  of  Belgium.  They  are  o:!on                buil t  on 
a  circular  concrete  foundation.  A  brick  wall  4  - 5  ft.  high  rt"tains  the 
soil  and  steps  are  constructed  to -form  the  entrance.  A  sketch  of  this  is 
shmrln  at  Fig.  13. 
Brickwork  is  used  mostly  inland  for  the  construction  of  small  shelters 
and  M.G.  posts t  the  thickness  of  brickwork  seldom  oxceQding  12  in. 
CONCRETE  SHELTERS  AND         POSTS. 
T,he  construction  of  shelters  for                 O.:::s.,  ammunition  and 
              has  in  most  cases  been  in  concrete.  Tho  :9crcentage  reinforcement 
is  not  known  though  the  use  of  steel  is  believed  to  bo  standardised  for  tho 
iM)ortant            
"lherever  :oossible  the  construction  is,      in  the  ground  to  roof  level. 
In  many  cases  comuletely  undorground  construction  has'-bepn  undertaken. 
(a)  The  following  dimensions  are                 of  cne  area:-
!Thickness 
- 2  -
            of  walls 
If  tl  roof 
      of  soil  on  roof 
3-5ft.     
  ft..     . 
6k  ft.  C  - 3  ,0 
Ammn. 
3  ft. 
3  ft. 
- 4  ft. 
(b)  A  ty-')e  of  German  concrete  shol t I-r  which  has  beon  erected  along  the 
Channol  coast  is  shown  in  Figs.  14  - 16.  It  is  btJli0v.;0.  that  this  d\..zign 
has  boon  adonted  as  one  form  of           construction. 
Tho  overall  thickness  of  concrete,         thd  small  retaining  wall  to 
tho  emergency  Gxit,  is  3  ft.  3.  in.,  and  the  total  amOl1_nt  of  concrete  is 
125  cubic  metres. 
(c)  .A          of  combined  artillory  observation  and  command  :nost  is  shown 
at  Figs.  17  and  18.  The  int ernal  lay-out  of  accolflmod.a t ion  is  apnroxima t 
only  and  may  have  to  be  f.09dificd  when  further  information  is  racei vea .. 
There  have  been  reliable  reports  of  thf:  siting  of  0mnlacements  dan-
"oro1J.sly  near  the  edge  of  cliffs..  Shou.ld  this  rovo  to  be  the  case,  gun-
firo  directed  between  tho  forward  edge  of  the  cliff and  the             
might  1u1dermine  the  foundations  suffioiently  to  neutralise  the           
It  is  im!Jrobable,  however,  th8.t  there  are  many  instances  of  this  for 
obvious  engineering  reasons.  The  sit tng  0  f  em::>lacemcnts  with  re spect  to 
the  cliff  face  will  vary  according  to  the  type  of  grOUl'ld..  The  line  of  the 
cliff  face  in  Fig.  18  should  not  be  taken  Ii          
(d)  Cue;  exaur.91e  of  a  camouflaged  :,)osition,  whicj1  a:1:',lears  to  be  an  artillery 
position  oombined  with  either  a  command  post  or  crews  quarters  is  shown  at 
Fig.  19.  Note  the  method  of  building  a  "dummy  du.no"  tc  conceal  the  posi tiol1 
in  dune  country. 
GERMAN  WEST  WALL,  1939. 
               Oi!'  EARLIER  WORKS. 
Some  of  the  original              ts  were  s trvngthenod  by  the  provis ion 
of  sch-tirzcn,  which  consisted  of        sheet          outside  the\ line  of  thG 
existing  walls,  the  earth  being  excavated  and  th.:..;  s=:lace  filled  wi th  unre--
inforced  concrete. 
Above  this  work  a  wall  of  reinforced  concreto              was 
constructed  against  the  existing  front  wall. 
n 
The  :')robable  "')ur:.oose  of  the  Schurzen  was  to  -')rotect  the  foundations" 
against  erosion  as  wC'll'as  ,?rojectile-s.  It-         be  noted  that  the  SchurzG'I): 
          !?rincipally  on  the  Gm:placements  bull t  on  the  banks  of  tho  Rhine. 
These  nrotective  works  were  nrobablw- found  nocessary  because  of  the 
rushed  carl-if:. r  construction  and  the  insufficient  tnickness  of  concrete  in 
tho  walls. 
The  thickness  of  the  added  reinforced  concrotu  \'lal1s  is  said  to  be 
from  3  ft.  4  in.  to  5  ft.  0  in. I  while  the  thic
1
::noss  of  the  front  anron 
is  3  ft.  4  in.  (Figs.  20  - 22). 
ff 
       He  1939  (Kalll!'fraume).  f1 t'l' ,,"  ,  . 
(a)  Roinforced  concreteU  f. b-I if    >'1  ". 
In  the  first  half  of  1939                         ,{hf'hickness  of  the 
concrete  was  increased  and  the  following  details  hav,-!  0G(.n  noted: 
il    
/  (i,' 
- 3  -
noted:-
( i             s   anti ,. rQ o'fs 
             "'J!ates  in  loo"iholf;s 
(iii)                   of  one 
cubl  metre  of  mixed  concrete:-
Gravel  or  broken  stone 
1.5/8  In.  to  3/8  in. 
     gravel    in.  to  i  in 
Sand  u:')  to  1/ g  in. 
Cement 
1938 
5 ft 
3.     in. 
1939 
6  ft.  3  in. 
7.1/8  in .. 
The:  grade  of  cement  USL!d  was  quick  setting  C1!1cl  Irooably  corres",?ondcd 
to  tho  British  grade  of  "Ferrocrete!l.  There  is  :0  reliable  data  of  t,he 
uator  c6111ent  r.atic  adopted  on  these  works  anet  all  tiJat  can  'be  said.  rogard-
    this  is  that  the  concrete  "'las               to  ha,vo  beon  a  sloppy' mix. 
One:  isolated  report  mentioned  that  the  minimum  cruslrLl[,'  resistance  was 
laici  dOvID  as  3,550  Ibs/sq.in.  (250  kg/cm
2
). 
Removal  ef  thE!  shuttering  was  usually  5  to.  6  days        :leuring. 
Hhere  aprons  WfT0  docided      n  they  w-: re  cast  in  one:  with  the  feund:J,-
tion  and  walls. 
(iv)  The  reinforcement  was  uniformly  distributGd  by  means  of 
horizontal  and  vertical  'mats J  through  the  entire  thic!{ness  of  the  con-
croto. 
Diarn.  ef  bars 
Spacing 
" 
t 1'1'- t'  int nrvals 
(horizental  er  v3rtical) 
5/8  in.  to  1/2  in. 
6  in. 
18  in. 
(v)  Additional  rcinforcem(;nt  was  fixed  as            
Reof: 
R. S .  j  s.  s i  z e  3  tG  10  iD,       
"  s'oacing 
1  ft.  to.  1  ft.  6  in. 
Le',11er  flanges  ef  R.S.Js.               7/32  in.  ste(;l  plates  to 
ferm  permanently  fixod  shutte;ring  tc:  th-.;                  ' 
(b)  Do_C?rs.  The  euter  deers  were  made  eut  of       in.  st3(1  J11ates  4  ft. 
x  2  ft.  7  in  wide.  In  oxcel)tienal  cas,'-s  the  ontrance  deers  were  made  of 
timber  1.1/ g  in.          faced  on  bo th  side?  \'1:i. t:J  1/ S  in.        :pla tc s. 
Theso  doers  measure  6  ft.  3  in,  x  2  ft.  7  in. 
Seme  large                have  been  re'i)ortod  as  h:"1ving  4  ft.  7  in. 
er  5  ft.  3      x  6  ft.  7  in.  wide  steel  felding  deors  having  two  leaves. 
(0)  Lighting.  Aleng  tho  R>ino  the  emplacements  arc  lit by  acetylene  or' 
:)araffin.  In  some  cases  electric  lighting  has  bC0n  rq1ert ed. 
(d)  Tole:!)hcne.  Large  scale  fitting  of  te18phonos  has  been  re-'-'ort8d. 
The  terminals  arc  fixed  in  an          eutside  the  werk  somewhere  near  the 
ontranco. 
- 4  -
APPENDIX t 
    __  " 
           ",.----vvv,---""_  -
a 
1m.  \  CAMOUfLAGE 
1         -
I 
I 
           4m.                 
fRONT  ELEVATION 
EMPLACEMENT 
SECTION  THROUGH  DUNES 
AMN. 
STORE 
J 
Sm. 
I TRANSIT 
MAGAZ1NE 
\ 
\, 
'---J\j 
FIG ..  3 
SKETCH 
OF  GERMAN 
EMPLACEMENT 
IN  REiN FORCED 
CONCRETE.. 
SHEtTER  fOR  CREW  0' ..  Armoured  air  vents,  and.  in 
  n  some  ca.ses  an  IrOIl  Ladder 
Li-------------_
J 
to  9uI)  platform  on  t00 
GROUND  PLAN 
ALL  DIMENSIONS  IN  METRES 
APPENDIX 
Flq.4 
=.  - -_ - - ~  ~  - : e. o  --=--
f1G.5 
' , ~  ~ ' . 
\  ,'\ 
Or \  .. 
...-
, '. 
RECONSTRUCTED  FROM  PHOTOQRAPHS 
NOV 
a  =- p/Yot 
b  --        J1?9_ 
c  "- PrDbable        Recess 
       for  Sheil.  &.           
Steel  Shield  Filled 
over,        
FRONT  VIEW 
APPENDIX 
PLAN 
NOT        
Probable 
-----y-aEion 
FIG.6 
FIe..  7 
RECONSTRUCTION  FROM  A  PHOTOGRAPH 
APPENDIX 
FIG,S 
VI 
REAR  VIEW 
..  " 
(I  ell
tI  (I 
It  (I 
..  0 
e  0 
STEEL  BASE  TO  TURRET 
CEMENT  FILLET 
RECONSTRUCTED  FROM 
PHOTOg RAPHS 
                                                  
APPEN DIX 
Flc;.IO 
-
SECTION 
  
  
           ..                ... '!.;. S 
....  r... 
",     
'0' 
 
 
"6 
  . 
LOOPHOLE 
It 
I' :.. 
r-.. 
B 
..  
   
r.:c:-
  .. o  D  .. 
\!J 
'0 
,  .. 
b 
              ... 
   
        ... t:P.,  .... 
  -;0 
tlJc 
  ..    .. 
   
..   
II. 
I' 
., 
   
t 
         
  O 
10 
P 
lH 
00  VI 
    
""""-
  
PROMENADE 
....  .  . 
.."                     
PLAN 
NOT  TO  SCALE. 
'-.., .  IO.c:!./4 
,.., ov       A  6""'. 
APPENDIX 
FIG, II 
I  I 
I 
SECTION 
SEA  WALL 
LOOPHOLES 
'c."  b  .., 
I  Dt:                                           
...  v                              z::;>.,1?  a(Q 
PLAN 
NOT  TO  SCALE 
MANHOLE 
...l.lL 
PROMENADE 
APPENDIX 
LPOPHOLES 
ltL 
THIS  WALL 
   
t-It----- 19  8  - - - - ~ 
FJ Ci.  12 
T 
9'''0- ( ~ m . ) 
E.NTRANCE 
THICKNESS  OF  ROOF  3
1 
4"  (I  MET RE) 
SKETCH  PLAN 
CONCRETE 
FOUNDATION 
APPENDIX 
SECTION 
NOT  TO  SCALE 
PLAN 
SKeTCH  OF  GERMAN  M ~ g .  POST 
FIG.  13 
G.L. 
I  I. 
1  ... -43-
I 
1 
A--
_1_ '----..&.----I 
TOTAL  AMOUNT  OF 
CONCRETE       
CUB1C  YARDS. 
I 
3'3
1 
I 
I 
9
1
0" 
I 
1 
I 
I 
3
1
3" 
I 
,  J 
r-
Ie 
-r 
I 
l 
I 
--3                  I 
0.... 
::..l 
I 
f--B 
17'  ," 
__ 25'  3
M 
_  _  I  t  I  /1  .L 
10       
PLAN 
 
 
'1J 
-0 
fTJ 
Z 
o 
x 
.!.=LL l  0  t3 J "! 1  '2  I 
..!.:!..-O  '  '4.3:.    ,..,.,
                                                    
-. 
.& 
(f) 
-..., 
APPENDIX 
~ - - = 
! 
at') 
-0) 
-...-... 
&I) 
---
FIG.  IS 
~ 
z 
0 
r-
U 
w 
(/) 
-0 
rz 
_ ~ ~ ~ _ ~ ~ "  __________________________  ....J-L....,J 
At  gil 
j.....-.-"'t  -
APPENDIX 
FIe;.  16 
a
t  u 
-T--- 1---
A'  9' 
.,...J .... --""1'  --..., 
I  :  I 
~   -   -   -   .   -   -   -   -   -   -   -   -   J   - - - -1- - - - -. 
I  I 
If  I 
o -- - -- ..... /-0. 
SECTION  C  D 
I  I 
4'9'" 
I 
I 
-i 
---------T 
I  II
30  & 
      
I  I 
1-             
1  ,  ,  ,     ------- 1 
   _____ - +_ 
I  I 
,....  4&  7
u 
-I'"  19'  8
11
------1 
r  fJ 
A- - --- --'- ---- ---
PLAN 
COMBINED 
ARTr LLERY  &  COM MAND  POST 
:!! 
() 
I 
.........
 
-u 
-u 
rn 
Z 
o 
x 
L 
f  + 
~  ~  j  ~ 
t 
106 
4'  II" 
SECTION  A-8 
COMBINED 
ARTILLERY  &  COMMAND  POST 
--r 
7
1
3" 
~ = - ~ _ ~ A  "S" 
CLIFF 
FACE 
DRAIN 
PIPE 
"'T1
D 
CD 
 
-0 
-U 
rn 
Z 
o 
X 
DEClASSIflEll 
G.$  R MAN  FIE L  D W Q ~  K S 
NOTES  NO,  2. 
CONTENTS 
1"  Genera.l, 
2.  Magazines. 
3.  Shelters  (personnel  and  equipment.) 
4.  O.Fs.  with  shelter. 
5.  Emplacements  with  shelter. 
6.  Underground  pillboxes. 
7.  Above  ground  pillboxes. 
8.  Miscellaneous. 
(Iv!. 1,10) 
The  War  Office. 
0160/2409  (H.I .1<:'. 
June  1943 
Distribution:  List  nEn  (as  revisecl  to  June  134:3) 
CCFY  :To.  2;; 
             
I"  GENEF..At  
1.  Standard  construction  methods. 
2.  Materials  used  in  concrete. 
3.  Strength  of  defences. 
2.  MAGAZ INES . 
1.  Type  la. 
2. 
II 
2a. 
3. 
II 
L  407 
3.  SHELTE-qS 
(PERSONNEL  &               
1.  Type 
- 12  men 
2. 
It 
117 
3. 
tr 
140 
4, 
ft 
250 
5. 
f! 
L  405 
6. 
ft 
608 
7. 
II 
621 
8. 
n 
629 
4.  O.Ps.  WITH  SHELTER 
1.  Type  143 
2. 
11
11 :s e its t ancl If 
3. 
" 
502 
5.                WITH         
1.  Type 
L  :Ol 
2 .. 
If 
L  402 
3, 
If 
L  406 
6.  mIDERGRr:UND  PILLBOXES. 
1.  'rype  If  Tobruk-standU  58d 
2, 
If 
-ditto- By ..  MG. 
3. 
II 
If Ringstandll 
4. 
II 
tlpanzerste11ung
tl 
5.  Tank  turrets 
7.  ABOVE  GP.OUND  PILLBOXES. 
1.  MG.  or  Lt.  Gun  type 
8.  MISCELLANEOUS 
1.  Loophole  in            shelter 
INDEX  TO              
Tobruk-stand  for  Heavy  MG. 
Above  ground  pillboxes 
Leitstand 
Single         o.P.  or  Pillbox 
Heavy 0                 
.  tt:tJ1SSlf1EO 
  
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
Plate 
Plates 
Plate 
Plates 
Plates 
1 
2  & 3 
4 
5,  6  & 7 
8  &  9 
Of.lLtflt; 
In           to  providing  the  latest           
and  prachce  in. Europe  thes"  notes  bring                
German  Fieldworks,         No.1. 
German  concrete  design 
information  given  in 
Photographs  of  an  O.F/Pillbox,  which  is  shown  at  figs.  4  &  5  of  Hotes 
No.1,  are  given  in  Plates  5,  6  and  7  at  the  back  of  this  uublication.  The 
photographs  in  Plates  8  &  9  are  of  a  heavy  gun  emplacement",  sketches  of  which 
'N,;re  given  in  figs.  6,  7  and  8  of  Note s  No.1. 
1.          CONSTRUCTION          . 
.An  official  GE'rman  manual  (Stell1mgsbau  D  585)- recently  captured  in  North 
Africa  gives  details  of  the  methods  to  be  employed  in  the  construction  of 
fortifications  in  concrete.  The  manual  is  dated  1941. 
In  small  pillboxes  9  ft.  2  in,  x  6  ft.  7  in.  int"rnal  measurement  the 
concreie  is  to  be  I  metre  (3  ft.  3  in.)  thick.  The  rear  wall  is  to  be  2  ft. 
thick  with  an  exit  1  metre  (3  ft. 0 3  in.)  high. 
Unclerground  personnel  shel ters  in  concrete  shall  have  walls  and  roof 
3  ft.  3  in.  thick.  The  inside  of  the  shelter  is  to  be  lagged  with  3  in. 
tirrtber  ancl.  the  retaining  wall  onposite  the  shelter  is  to  be  1  ft.  8  in.  thick. 
Details  are  given  of  the  method  for                existing  cellars. 
Concrete  walls  3  ft.  3  in.  thick  are  to  be  constructed  to  the  exterior  face  of 
the  existing  walls  with  suitable  emergency  exits  where  necessary.  The  exist-
ing  cellar  ceiling  is  to  'be  su-pported  "dth:  tirrlber  anet          and  a  concr8te 
roof  3  ft.  3  in.  thick  is  provided  for. 
A  design  for  an  improvised  pillbox  is  also  given  in  the  manual.  It 
cons ist s  of  a  timber  const ruct ion  7  ft.   in.  x  4  ft.  6  in.  ins ide  moaSuTOffit;nt 
using  4  x  4  in.  and_  2  in.  timber.  A  steel  lo'ophole  plate  is  bolted  across 
the  width  of  the  structure  and  the  position  is  designed  for  2  men  with  an  lOG. 
The  earth  covering  on  the  roof  is  given  as  12  in. 
2.              USEr'  IN  COHC3ETE. 
There  is  no  information            on  the  typo  and  quality  of        stone 
or  gravGl  used  in  German  fieldworks.  The  materials  will  cert8inly  vary  in 
different  areas. 
One  sample  of  cement  has  been  received  from  a  sourCE- and  it  is  belL.,v,,'; 
that  this  Was  obtained  from  the            PENINSULA.  This  sample  had  bucn 
stored  for  a  time  in  a  cardboard  box  and  might,  ther8fore,  be  aerated. or 
carbonated.  The  results  of  the  analysis  are  as  follows:-
(1)  Chemical  Analysis  (in  pl-'rctJntagl's) 
CaO  48.10  Ti02 
0.33 
MgO  3.71   o
Hn
203 
0.3D 
K2
0 
0.85 
!-
Ta
20 
0.31 
SC
3 
1,63 
S  other  than  S03 
0.82 
(ii)  Density 
, 
/)  1,..9.1  "gm.  per  cc. 
UrI" 
... t,.,l ,if (an 
         
Jlto 
(iii) 
(iv) 
Sieve          
!te sid  ue  \) n .B ! S  
.,  , 
72  mesh  sieve 
11 II  II 
170 
II  II 
Passing  the 
" 
170 
II  II 
Finenoss 
Spocific  surface    2,950  em.  2jgm. 
permeability  method. 
    
6.3% 
93.7qb 
            
(v)  l'Jiiscroscope 
The  material  appearo0  to  be  a  mixture  of  Portland  cemont  \'lith  a 
considerable  amount  (probably  over  50%)  of  glassy  material.  The 
coarse  fraction  (72  - 170  mesh  matprial)  was  almost  entirely  mado 
uu  of  the  glassy  subst8nce,  wpich      similar  to  a  dense,  well 
granulated  blast-furna.ce  slag_ 
(vi)  Small  scale           
Sample 
Normal 
Portland 
(B.C.37) 
Rapid 
Hardening 
Portland 
(F.365) 
Sample 
undor 
t,,;st 
Tests  were  made  on  * in.  cubes.  Comparative  tests  wero  mado 
with  the  normal  ane.  rapid  hardening  Portlanc.  cement  samplds. 
Crushing  strength 
small  scale  tosts,  1 
mortars.  wlc  0.50 
Ib/sq.  in. 
1  3  7  28 
3 
day  (Jays 
days  days 
516  1360  1948 
848  1848  2544 
136  380  616 
1 
1 
day 
764 
942 
---------
Crushing  strength 
2  :  4  concrete  4  in.  cub0s, 
w/c.  0.60. 
Ib./sq.in. 
3 
days 
2020 
2310 
7 
days 
3C40 
3460 
28 
days 
4990 
bUUb 
( 200 )  ( 5('{ )  ( 85C)?: 
*  The  figures  in  brackets  are  estimatea  values  derived  from  a 
graph  of  the  relation  between  small  anc1.  large  scale  for  two 
known  cements. 
(vii)  Conclusion. 
N0arly  the  data  are  consistent  with  the  SAmple  being  a 
Portland  blast-furnace  cement.  The  ratio  of  Portland  cement  to 
granu18ted  slag  appears  to  be  a:  mixture  of  between  25  - 50% 
Portl.:-'nd  cement  with  75  - 50%  grRnulatecl  slag.  There  is  a       
probability  th't  the  lime  content  of  the  is  low  for  a  slag 
which  is  to  be  used  in  cement.      dtrength  and  rate  of  str8ngth 
d.cvclopment  is  v8ry  low.  This  may  be  due  to                          
results  are  consistent       what  might  be                    . It.\J 
- 2  - ,,\\10.' .1"  '  . 
U,\    ... 
,Ill') t;;w;  1l  :11:  :t' 
l.-,  L                  
"--    r  .. '1  ,  '-I  f' 
percentage  slag  which - is '-roW'i                therefore,  not  very  a"'.tive. 
It  may  'be  estimated.  that  a  cement  0: \hi.'s 'trP.G  is  not  likely  to  give 
strengths  equivalent  to  normal  Portland  cemGnts  until        12 
months  old. 
3.           OF  DEFENCES. 
Following  is  a  summary  of  the  main  differences  between  strongly  9,n.:".  loss 
strongly  held  areas.'  In  less  strongly  held  area:-
(i)  Strong  point s  of  all  kind.s  will  be  further  apart,  say  3CCC  yaris 
on  an  average  instead  of  ICC ('\  yards.  This  is,  however,  oft3n  J.ue 
to  the  difficult  nature  of  the  coast;  and  the  strong  paints  will, 
of  course t  not  be            spaced.,  but  to  sui t  the  ground.  Strong 
points  will  be  more  elongated.  and.  less  adapted  for  all-round  defence. 
(ii)  Concrete  will  protably  be  3  ft.  3  in.  thick  instead  of  6  ft.  6  in. 
thi ck.  Pill bOX8 swill  tend  t 0       relat i ve ly  common"  r  in  compari so n 
with  shelters  although  the  latter  will  still             
(iii)  Positions  siteo.  back  from  the  coast  will  have  little  or  no 
construction  in  contrete. 
- 3  -
1.  TY'j8  la. 
I   
A  (I.rawing  of  this  is  given  at  append.ix  1 ..         principal  dimension.s a.r.e 
as  follows:_ 
Length.  (axel.  passage) 
       
          of  walls 
n  If  roof 
Total  concr2t,,;; 
2.  TJ'0G  2a. 
A  clrawing  of  this  is         at             2. 
as  fol1ows:-
LvilgtL.  (excl.          
      
          of  walls 
II  II  roof 
Total  concrt:t,l 
Roinforc:.;mcnt 
! 
25  ft,  3  in. 
19  ft ..  7  in. 
3  ft.  3  in. 
.. 3  ft.  3  in. 
300  cu,  yd. 
no  information 
    principal             arc 
37  ft.  9  in. 
47  ft.  6  in. 
6  ft.  7  in.  max. 
6  ft.  7  in._. flax. 
lOCO  cu.  yd  .  auprox. 
no  infOJ"rr:fltion. 
        is  sorno  doubt  wheth:;r  the:  thickn"'ss  Qf  concrJt.  in  the  wa.lls  ani 
roof  is  in  eV:3ry  instance  6  ft.  7  in.  thick.  It  is  -possible  thAt  mEl.ny  of 
this  typo  arc  about, 1. 5C  m.  (4  ft.  11  in.)  thick. 
        L  4C7. 
A  drawing  of  the  8.8      or  10.5      A.A.  Gun  Ammunition  Sheltor  is  given 
at  app ')no.ix  3. 
Ho  oth.)r  dotails  ar')  avai1ab10  except  as  tabulatGd  b,-low:-
L,'ngth  42  ft.  7  in. 
i'iici_th 
41  ft.  7  in. 
Height  16  ft.  7  in. 
:5.oof  level  above  ground  3  ft.  3  in. 
Thicknclss  of  walls  3  ft.  3  in. 
n  II 
roof 
3  ft.  3  in. 
Excavation  leOO  cu.  yd.  appro:x:. 
Total  concreto 
    cu,  yd. 
II 
Woight  of  re inforc;:;rr.-.:'nt  35  tons. 
" 
....  4:  -
I" ._-,  ,-, 
.'  f!" 
.             
APPENDiX  1 
I 
6 
PLA'" 
1 
       XOO 
A--A 
       
                                               r  . \      
          1------( 
#..l.  10        
A  .... il43  A6w 
" I' 
I,.', . :.  1--__  --1 
                                  l/t 
If:-C.I'ON  B-& 
MAGAZINE- - TYPE: 
1(] 
kp-E.ndix  2 
.....  , ..  ----------.4]' 01A 
I 
~   ~   ~   ~   ~   ~   ~   ~   ~   -   -   ~   -   -   ~   ~   -   -   -   -   ~   ~   ~   -   -   ~   
TYPE-
2.0 
APPENDIX  3 
   
re----41 7 ---... 
PLAN 
      ,/2.'::>0 
         ...    ':i. :.i -.                              
    ......                        .co ,,' ..-..0  .: .,.. '4'" . '" 
.. : ...... - ........ ",  ........  __  -- ___ ..t.: 
  l. 10  b/7:J..61 
J'un4     ":;:'-1 
.. ..  . . 
:::)  ,J6 7 
i        '.    ..... 0  ..... ,::;:   I 
41  ...  ., ......    II.  b   ... - . !':  ___ ... _ .... _i 
...... ".  "-r  .....  -   v'"  _.-, .....  -,  _  .,.F'   
SE:C.JIO-"  A-A 
8-8cm.  OR 10-5cm.  A.A.                       
TYPE:  LA-OJ 
3. 
1.  Type  - 12  men. 
A  (l.rawing  of  B  personnel  shelter  for  12  ;;:en  is  given  fit  al"1')enr..ix  4. 
There  are  t,-,'o  st8nrard  tj-nes t  the  one  illustrated  anc.l  one  for  6  men
t 
and  these 
are  tyryicC'J      the  ty-oe  to  be        on  the                            The  type  of  shel ter 
for  6  reen  has  a floor  s-pace  of  12  ft.  x  8  ft.  The  thickness  cf  con0ret.e  i.s 
only  3  it.  3.      as           to  6  ft.  6  in.  in  other  areas  encl.  're inforcement 
arY')ears  to  be  very  J.ight.  There  are  only  3  rows  of  vertical  rars     - 3/4  .:r:. 
dia.meter  anl5  horiz;)ntal  reinforcement  is  not  :nectione:'.  . 
The 
principal 
a.imens ions are  as  follow8!-
Length  of  shelter 
21  ft,  4  in. 
Wic:.th 
11
" 
22  ft.  11  in  
.  Shel ter  space 
16  ft.  L  ill.  (s1,uare) 
         of  shelter  over  "bunkers
u 
34  ft.  0  in.. 
      c;th  of  ent ranee  pas sage 
D  ft,  9  in. 
Thickness.  of  walls  3  ft.  3  in. 
II  n 
roof  :3  ft.  3  in. 
Earth  cover  (probable  minimum)  1  ft..  6  in, 
Points  of           are  as  follows:-
   i)  The  two  arnmuni t ion  recesses  ("bunkers H)  on  each  s i0.e  of  the  entrance. 
(1i.)  The  unarmoured  steel  door  about  2  in.  thiok.  The  (loor  can  only  oe 
closed  on  the  inside. 
(iii)  There  are  no  loopholes  in  the  walls  or  in  the  entrance, 
(iY)                      
(v)  There  is  a  stove  for  heating  Bne  electric  light  is  installed.;  "'out 
no  water  is  laid  on. 
2.  TYFe  117. 
A:-j  enctix  5  shows  a  type  of  shelter  which  is  user  for  headquarters.  The 
princioal  d.imens i,ells  are  as  follows:-
Length. 
65  ft.  7  in. 
\1io.th 
42  ft.  a  in. 
1':'idth  over  'P ill  box 
[,C 
ft.  8  in. 
Thickness  of  roof  6  ft.  6  'in. 
n  It 
walls  6  ft.  6  in. 
ff 
" 
internal  walls  3  ft.  3  in.  or  less 
Concrete  in  roof 
720  cu.  yd.  approx. 
" 
If 
externAl  walls  40C  cu.  yd. 
II 
If 
" 
floor 
22C  cu. 
II 
II  II 
internal  walls  100  cu. 
II 
.  .. 
P..e.inf 0  rcerr.en t 
:'tet-ails  not  available  but 
kr.o
1
1\'n  to  be  reinforced 
throughout  full  thickness 
of  walls  and  roof. 
It  appears'thet  this  type  rr:a.y  be  subject  to  a  nw:.ber  of  modificatiors 
            on  the  wishes       e  CO,IT.rran:ier  an:i  the  purnose  f?r  Whi?h  it  is  to  be 
used.  It  Tr.cy  also  be  used,'  ely  as  a  wiT  or  teleyhone  lTIstallattan and 
provision  has  been  ma:ie  tc/  .  .'          if  cansio.ered      
:,(1"1/ 
  
This  Distributing  or  Switching  Chp-mber  is  the  s:naller  of  two  types .a....'1!3  is 
      at  ap'Oen,iix  6.  The  principal  dimens ions  are  as  follows: 
Length 
'i,rid.th 
Height  of  concrete  above  ground. 
Eeight  of  roof  ri 
Thickness  of  walls 
1t  "roof 
":)einforcement 
i:utmlASS1FtD 
16  ft.  C  in.  (approx) 
4  ft.  11  in. 
4  ft.  11  in. 
no  cletails 
This  chamber  or  shelter  is         in               one  being  found.  at  each 
      where  fortress  cable  leading  to  individual  strongpoints  leaves  the      
long-Cl.istance  cable
o 
These  chambers  are  the  points  fro;.',  which  the  routing  is 
controlled.  ana.  are  numbered.  consecutively  from  ]last  to  West.  Normally,  there 
will  b8  no  signals  personnel  locateo  permanently 'at  the  chamber. 
The  asoestos  sheet  roof  is  an  interesting  piece  of  camouflage. 
A  variant  .of  this  type  of  structure  is  rerorted  from  BRII'-:::Al'TY.           
tlie  type  14C  is  above  ground.  the  BRIT'::,Al\TY  tYJ)e  is  entirely  undergrouno.  and  has 
thin  walls.  The  interior  dimensions  appear  to  be  10  ft,  x  10  ft.  x  8  ft.  and 
steps  lead  down  to  the  entrance.  A  very  small  pitchoc.  roof  is  constructeo. 
along  the  side  next  to  the  steps  and  has  a  small  fanlight  in  the  gablo. 
4,  me  250. 
A  d.rawing  of  this t  the  larger  type,  is  shown  at  appendix  7,  sheet s  1  and  2. 
The  principal  dimenslons  are  as  follows:-
Length  21  ft.  11  in. 
Wio_th  18  ft.  C  in. 
Thickness  of  walls  4  ft.  11  in. 
n 
" 
roof  4  ft,  11  in. 
Reinforcement  no  details. 
It  is  l)ossible  that  this  tyne  is  the  "Grossschaltstelle
tt 
whieh  aDpears  at 
the  more  corr:plex  cable  junction  points.  At  one  of  these  Ie  circuit  cabl::1s 
enter  the  chamber"  and  from  it  radiate  two  5  circuit  ano.  one  10  cireui t  cables, 
each  leaoing  to  a  strongnOint  on  the  coast.  A chamber  in  Which  thare     
f";lwer  distribution  frames  woul6  be  an  ord.insry  tlSr.11altstelle
lf 
of  140          
A           for  Flak  R.D.F.  Equi-:->ment  and  Detachment  is  shown  at  a:T'1cndix  8  
.A;:?:?raximat e  details  are  as  follows:-
I.J8ngth 
'tlTidth 
Height 
Roof  level  above  ground 
Thickness  of  walls 
IT  It  roof 
Excavation 
Total  concrete 
Reinforcement 
_'t  6 _ 
41  ft.  3  in. 
33  ft.  0 
16  ft.  6 
3  ft.  3  in. 
6  ft.  7  in. 
6  ft.  7  in. 
800  cu.  yd. 
80n  cu..  yd. 
35  tons 
an"'1rox. 
11
/6.  Type 
tt  ".,  49  ft.  0  in. 
'Length  (shelter) 
"  (incl.  C.P.) 
        (shelter) 
n  (incl.  nillbox) 
            externHl  walls 
n  roof  ' 
Concrete  in  roof 
If 
" 
external  \'Ialls 
Total  conorHte 
R ;inforc8ment 
58.  ft.  0  in. 
45  ft.  9  in. 
,  54ft   r  il  
.  :,.  6  ft.  7  in. 
6 ft.  7  in. 
57
r
' cu..  yd.  a"n'Y'lr()x. 
35
0 
cu.  yd.  " 
,  1300  cu.  yd. 
(3/4  in.  diam.  bars. 
..  (1/2  in.  "  II 
S:'l'ltors  of  this       ha,v.]  b:  on              at  v::c"'5.os  ",laoes  in          
and  '''orth  FRA2'-CE.  The  rein;forcement  in  the  roof  CO:1S:i.Sts  of  J;.  in.  diameter 
c3..rs  s:)ot-
1T
olded  tr;  form  mats  (similar  to  'B.R.C,)      7  ill.  squares.  Th;'  rr.a.ts 
arc  7             The  reinforcement  in  the  walls  consists  of  3/4  in.          
bars  at  10  in.  centres,  ::;>rosUInably  both                and  v,:rtic::llly.  The 
              ty  of  bars  is  unknown. 
A  sm::.ll  :)illbox  is  arranged  in  the  wing  of  the  Etructurt:'  and  the  loo-:1hc 10 
covers  ;)cth  ontranc:s.  Tho  entrances  to  the  shclt:".r  J,re  '  rovidod  \vith  gas-
      doors  or  screens. 
                     em:olacement  is  rGferred  to  as  t:1C  "0:,  '11  observeI'll  and  is 
                 \';ith  s}?oaking-tubo,  tele'-jhone  and  '"Jireloss  set.  The  post  probablY 
hLl s  _  ,i.l  Ii;. G   
It  is  laid  down  th:, t  one                    and  t'  .  .'O  \11r,'16ss  recesses  must  be 
built          all  shelters  of  this  ty110,  including  those  situated  in  rear  9  .  .rt:  s. 
Tho'  ireless  recesses  may,  however,  be  omitted,  ff  tho  Fortress  Signals       
concoraod  gives  authority. 
It  i8:-=:.1so  laid  down  that  all  lead-in  tubes  for              C!able  ILUSt  be 
(;xte:adod  from  10  to  15  metres  (33  - 50  It.)  beyond  t:'10  '.ralls,  in  'Jrder  to 
avoid  damage  to  the  cables. 
7            621. 
Some  dotails  of  this  ty-oe  are  available  and it  h..11l,(l  tbc  samo  general  eha""") 
a:lld  sizo  of  TY-OE::  629.  The  external  dimensions  arc            to  be  3
4 
ft.  9  in. 
x  32  ft.  and  the  walls  6  ft.  7 in.  thick.  The  sholter          to  be  for 
              o:"11y  and  !->rovidcd  with  t1.,1/0  entrances.  E3.C
1
1  entrance  may  be  oovf:r8d 
by  a  loo:'lhole  simil8.r  to  TJ-::oo  629.  The  shplter  contains  7  beds  and  it  is 
rC2,sonablo  to  su:'''no so  thR t  it  is  intended  to  :orovido  ac.ccn:modation  ft'r  a 
section  of  10  - 12  men. 
     S  tv.,e  of  shel t      'Provides  aocommoda t ion  for  t  dutRchffient  and  an 
A.Tk.  g;un. "?lans  and  sections  are  given  at  ap;Jondi:{  10.,          ts  1  and  2. 
Pril1ci:.Jal  dimensions  are  as  follows:-
Longth  (excluding  O.Ps.) 
If  (including  0 .Ps. ) 
Uidth     
Height' {"J'     
n                 ground  level 
          ,of  walls 
It       ': :;ro ':'Jr.
1 
/<" 
Q,uan tit Y  0 f              .'''''' 
n  "  exc.e;vYl,o n  ,; 
i'loight  of                             
1FJf it-J) 
36 
ft. 
9 
in. 
55 
ft. 
9 
L.l. 
36 
ft.  2  Ll. 
16  ft, 
9 
in. 
3 
ft. 
3 
hl. 
6 ft. 
1 
in. 
6  ft. 
7 
in. 
880  cu.  yd. 
!).")1')rox. 
1(100 
'31..1    ird, 
" 
33 
t,)"lS 
" 
Sheltors  of  this  design  aro  believed  to  h8.vO  b00l1               towards  the         
of  1942.  The  dosign  urovides  for  steEl  reinforcom-:nt  out  the  dr:.tg,ils  are 
not  klo':n.  .  ftlrlrlp 
         '\:         ! 
     shelter  is  si ted            of  the  gu.n                                      \, 
of       enomy  and  the  "ccrridor
lt 
to  the  emnlaccIDeD.t  i  "  . :1;','  I            in 
ccncruto.  The  entrance  to  the  crews t  quarters.:',  is  str>.f..;C';ared  and  a  lC0:nhole 
is  .  rGvidod  so  th?t  it  may  be  covered  by  small  arms  fLee.  Fote  the  nrovision 
for          the  chambAr  against  gas  
.  :-_D.              feature  is  the  construction  of  t1:TO  lITOBRUY"  ty:')e  O,?s., 
ona      oc:tc':l  'l,lJing  of  tho  building.  These  1')ositions 'arc  cC:'.u8cted  by 
telo:?hono  and  s)Jcaking  tube  to  the  crows t  qua.rt                    one  or 
ooth  0:  tho  O.Fs.  has  a  machine  gun. 
It  vill  be  seen  that  only  a  light  earth  covering  on  tho  roof  is  intended 
and  a        is  :Jrovided  to  master  tho  'edge  f'f  tho  ftll:tn9.:.'  !t i8  probar-:1e  that 
stool         1"vi11  be  found  to  :Jrotrude  through  tho  cellcret,),  in.  pr  near  this 
kor-;'')  Eti.l(1  it  is  thcught       these  are  for               camouflage  netting 
across  tho  entrance  and  passage. 
                is  provided  with  a  periscope  and  it          also  be  usod  by 
              since             has  boen  made  in  the  design  fer  uireless  masts  and 
cai:'lo  ducts. 
UNClASSlfl.P 
- g  -
 ".  0  ....  ,. 
.B:!i:.!t!t:o RCS D 
CON<:'RE:.Tf? 
. . 
. 
           4 
JYfTAININ6  WALL  .4( 
Of .       Q '",   
.    .  "  ..",  .; .:  " 
   -....    '  ...  0"   :"  ,,:  ,,':' 0  
,,'  . 
.. 
;  !.-
,  .' 
o 
o 
o 
o 
o 
o 
,  o 
o  ".  0  :   
      ..  :  '0;'.  ,-.., 
  >0  \  ,".,  1    "            ... 
     :  ..  :  :       .:"  1\   
........ \  ...  _  .'  0  "III' 
o 
o 
      ..            
PLAN 
5 .. -----1..-+0  .... 
$9"'19& 
STAfjDAB.D 
          A-A. 
                 INf:MTRY 
                  .. , 
<s  ,II. 
 .... :I'  
.."  '  .. 
.. --..  :  . 
APPf:ND1X  5' 
A 
  ___  ------..:=+----- 65'  7  .. -----------......1  ........  , 
M'- 10,b-/
699 
"""'Y     At9N 
,.J.  WIRELESS 
   7 
i 
P:>DE: ..  Ok.  Dh/.  HQ. 
MAST:!. 
     
A-A 
      TEll    rYPE:  117 
A 
M" \0. b/1.2.t 
J'unf2.4, A 
Appendix  b 
ELAN 
........ 
14- .3 .. --------...  .......jl
SCALE  '150 
RECESf._FOR. 
Ql!lJIDE  PLUG 
;  J  .... ".  '"   ....  ...  .;;....  .......      
     .>:  .'     . .' -"::'      .::      .. :i .;::.  '( \:          
I L.   .  .,.,  .'., '.  .'.  ..  4  "  .... -'.,  :';               I 
W':    " ' .. :  ';.:,  ":'        :  ':  ..  :         .:.: ::',                 
I  I'"  ..  (;I ':    ,'-.:"   ',/0  ......  '.  IC  .,  z;.  0.,,, ' 
I  I     .  fI,.  II'      .,  I  "' .. -:.  - :--..  .....  1  ,  .,   
_:....  .:.t. -= :::'                                     
. " 
'.'  *:         ..... '.,. -..
".""  , 0- '  ..  _. 
"  ..   . 
..   .... 
.  "  e..
1 
.,.  -     :  ..       
Cl-tAMB{:R -.TVPJ;  140 
       ... 1:: 
LE..AD-IN             
        DC 
..1 Ti!C.IiNC'H 
I  ,I, 
411 
. ,-'" ...   ....  '.,:  .  ,,,!, 
T. 
-4  N 
... 
,  " 
'. 
'. 
H 
4  n 
i 
PLAI'I 
.. ..- .. 
t"  (' 
-.,.:.  ......  -If>' 
. . ..   
,  " 
, " 
 . 
. ', 
.; "  ... ,  ....  '_:-.         ; 
.... 
" 
" 
,  ,I  -et..  . 
"  "',' 
.'  . '" - ; 
,  . 
, . 
S'=CT'ON  A-A 
/4" 
0'   
   II" 
"  ...  
   
I 
."/(/ 
,  0; 
   j  '. 
.. .. '" ..  ' 
....     
.......  -
" 
II 
:  I 
'j 
I, 
   
;J  ;: 
1111  II 
j. 
'I 
" 
!, 
I, 
I, 
" 
I, 
I, 
I 
.! 
. i 
. , ..  :      .  /---1---1 
I 
" 
4  1/ 
: - ....  "', #'; 
.'  .."  ,. 
,,:  ..         ...  ,  :'" 
;  , 
-.. ;          ]', 
.' 
     .... 
       
. ,. 
. '  .. 
   
,"
. , 
,. 
..:  #  r.
.     '. 
"' .. 
 :"",  . .,  - - ..       :..  
:.-..: 
 .- ., 
....... 
:  ::  ..     -'./ -            ; 
.-
.    ,. 
:  ,  . 
"",. 
. "  I.---.-_-.........    t---I---;. ",.-
. ,      1---..--+, '. 
     
     ...... ,C"".. : 
-0"  ._ 
!....  " .. 
p'  '0  ..  0, 
A 
         .-- TYPb- 2.50 
APPE-AU)U',  7 
,  .. .:;r 
I  2.  -*--
,  . 
,  0 
P1 
o 
T. 
  
i- :  -!- - -. -1 i  I 
I  1  I  I- - -:  I  I  t 
:  I  I  I  ,_  _  _  _  _  _..I  I  I:   
,....t.._ ---- - ------------------..!.-J.--____ L._L. ______ ..I._.l_"""_.a.. ____  .I. ... 
.. ---......   ............        ... - .. --....               .........          .... ---...           ..    ...  - _tI 
&&C!;SS 
82.& 
             
eJ.1lSlJ. 
       
      . 
. .               #   -:6."''' 
,:  .'  . :';:;'; ",  :,              . 
'J.  7  .  .. 
'.  '1  "  .:.  '., 
        ...   .. 
'.   : ': ..  '  ..  -.:  ....   :',           .'.: .   
  t'"           .  ..,  ....... II! 
. r  ..   .  ., 0.'  '.'  .,      
.  -t  '.  ' .  \ 1io  '.    -  
. ,  ,"". ..  ....  .. 
        . ..,:,    -.   
,  .. .'" ,..&.,  at   
:,  ....  '.:  .....  , .........  . 
 I  .           - .       . 
  ,  ....  :...  '.  "..    *  ..... 
I  .*.-.,..  ..  .  .-. 
',I  ,.,  '..    " .. 
,  I  I .  '.  ".;  '. .: 
'"  it".:.  . ' :,..   
1  I ....  "!. ..    - . ("  . 
 r .,  : i .:.  '.  '. ""  .' '.  :"  .... 
 ."'.   fI' 
1 , " ':,  :'.  .  .  '.  "".: .      , 
..  f'  -.    ':.  I  . (i 4/: ,  " 
\ r :.  '.  *    ...:       * 
  ,  \  .\..  ,   .:f  ,  ..  
  :  \.".- -!...          - - - --
' ....  _---- ....  ..:...    
 .;,.  .,.  ,.  .  tI... - - I 
, .  . ....  '* .. -.  ." ,.., ...             .....  --------....., 
.:       11.. JO-:.t:;?,...   ,.  ,          JI.. 
..  .    :;...., .. ,  .-.    .:.  I            '.  :  '  "  .  fl-
      ..  #  I  J    -....  .' til  --:  ,'.- 
,,..  I,   <    ". _     
,    ',-     ..."  f      I .  .......  .,,:  .. :, .... _,- ,. 
; :V  .  t             I>              ',,-: ,",  '      e'         . .. -
..  .  -: .... .,  .. .;- ..' ..  . ....  '/  .. -'  ....   "  .. 
.. 
6 
 "'.  .,   til ,.   /'. _  I  .  :"...  ,- I  .' 
....  -.--.... - - - -:- - -.:;- - - .-: - ..  /  . -.'  .  e..  ..  _  ..      
.--:    -"."  ........ - ..  ....,/  - .,,1'....  ''''J'     
....  ....-   __ -:--          ____  -;    :  ....      ... ,  til           
CUAM&E:Rw  - TYP  250 
'/ 
APPENDIX  8 
  if 
6  7 
........           
PLAN 
)C.ALk.      
         J:OR         R..D.F.  r:gUIPM(;NT_tf 
                  L405 
           9  SUllT_l_ 
1 
           
____________      55'               
n  ,  / 
/..,' 
. " 
.,:  ., 
  ' ...  ' 
4
  c  It 
:J  O. 
  I  . 
"  r-
  k:11R.7.!!.. 
.::-. 
I  II 
10' 2:' )(:6 
,  , 
//  Tf:;L:f'JlONI::- L.AV-IN 
/'  / 
,  / 
1.,3'  /'  X  I.:.;'  6" 
.. 
'.                   
12.'  E,;"  X  8' 2," 
    ..          'l /0' 2," ,( 6 
..:  ,,:  : .. ' 
                                                       ..  _  ..     __  ._._._. __  ,  __     ________         ___      __    __ r 
-I'  - I  tb  ..  .  tV.'             ... ,,'  .\.  : ..  , '     " 
.:,;'  .. ,  .. "    -c.  ....  I ..  wI  ..  'to ..  t  (.  ..     _- _  \           .        
.. '  ...  ""  = 6  7")  .  f  #..  . ..        .' ..       .'  ,  ': -
....         .!.  "f     ",:.;,  : .. : .....  r'"  ...t  I  \  "  ... _  .. 
.       ,"',  .:':, ,"  ..  . -"  "  .  , 
...... ,  "  ...  -   :.:-:::"'''   :  lito        "  .,  ... 
. .   
)  . 
cal 
...J 
...---..... ---, 
.. _.'- '-
'r : .-     .; 
l 
7If!LPHCNE 
t 
-A 
, 
" " ., 'f> 
.   ... ,  ,. 
  f 
"  ",.:.  ....  '"\ 
-I 
                                            VAL EM T "Q --==-TY  ___       _____  b_O_5_ 
. . () 
.  '  . 
  'eo 
. . \ .. 
..   
 
 
".  -.. 
.. 
L  ;.:::': 
Mf  1qt:>j     
          Ak\t,J. 
.... 
';" . 
,  V 
" 
" 
'-..  " 
         9  SUE:ETL 
A,J:./U:J  FgI<..  G-F jAINIft!" 
       CUV/3.1(.. 
.. 
"Ii'  . 
..  'l  '.' 
:-.i-.:  .  
:<>  I".  , 
#.  _. 
..... '. 
. ""'"  .  : 
SEC.f'ON  A--A 
HlIKEI ESj  J..E.AI.I  IN  l4lBEl 
e:::s: 
         &".e, 
SCALE:               
:- ... ..,      
         .  
OR..  EQUIVALENT 
ug =--JVPf:  608 
.. 
ENEMY 
         10 
         
    L: 
 
I 
I  .....                          
l!?l!.I<UA:.             !!!'!-" Mo9'iJ 
I 
I   
t
6'7  ..                   -----..........  1.  7'S" 
                                         
D+ 
.... 
Ii 
                  GUN     DlIACUMt;AlT          629 
1M  1.10,1::'770 .....  , 
  MAY      A.FIN  t 
         10 
       
.jLf;FE:  OF  FILLlhlJl  1 IN  10 
I                            .....                 .....                                           ....           __ 
 
        A-B 
I</(B  /(E./AININu              CAMCltlFLAG 
________ --, __ , ___ . _____          ___      
--- "  ""  .  ::----..-
----
SbCI'ON  C-D 
-
 
..:  t 
'4, 
This  is  o.n  artillery  ('.P.  and  shelter  and  a  nlan  is  sho\V'n  at  b'rJ:;endi::  11. 
The  :1rinci:nal  dimensions  arc  as  fo Ilbws:-
Length 
,'Tidth 
Thickness  of  walls 
44  ft.  0  in. 
29  ft.  2  in. 
G ft.  7 in. 
A  sectional  drawing  of  this             is                  not  availablE  9.nd 
the  reinforcemont.  if any,  is  not  known, 
Details  of  the  observation  turret  are  not  knO\'ll1  but  it  is  possi'tlo  that 
it  is  similar  to  that  used  in  TY,9G  502  (!)aragra"-)h  3). 
Tho  loc'lholo  in  the  :.1arty  wall  which  covers  th"  ...:utrallce  to  the  shel t  r 
is,    !arcntly,  built  on  th0  sk,  w,  This  may  not             out  in          
oulag  to  the  extra  work  req,uired  in  splay-cutting  the  shuttering. 
::oto  the  :?rovision  for  wirl:.-less  and  tolephone. 
2.  Ty:  '0  IILei tstand
lt 
 
::lato  4  shows  the  front  view  of  a  Battery  Obs'.Jrv  tioIl  and  Command  Post 
("Loitsta:ld").  This  design  is,  a':)parently,  a  standard,  ty
1
0  and  has  been 
dosignated  'L'  by  tho  Germans.  An  attempt  has  b  vn  mado  t
r
 disguise  the 
strt
1
,cturo  as  a  "Cafe  Francais";  this  a!>:t:')ears  rathor  in, fi'uctivE::  on               
but  is  -,)rooably  quite  decoptive  to      eye. 
Tho  structure  is  built  in  reinforced  concrete  and  thu  ,,,aIls  and  roof  are 
!lrobably  6  ft.  7  in.  thick.  The  height  aT)nears  tr:;  be  abcut  25  ft. 
It  is  ')robably  designE.d  for  low  dune  country  such  as  that  in  BELGIlJ1yl 
and  its  height  will  give  an  imnrcved  field  of  vieu.  j?lc-tes  5,  6  and  7  show  a 
single         structure  of  similar  design  which  may  bi  used  as  a  :pillbox 
or  an  o.?  This  latter  tY-r")c;  is  known  in  areas  such  as  L-,  'HAVRE  wht:'re  high 
cliffs  -)rovide  good  observation  1Joints. 
This       and  personnel  shelter  is  a  heavily  r,  infcrced  concrete  structure. 
A  ',11an  and  sections  are  given  at  a1-,pendix  12,  shc..::ts  1,  2  and  3.  The 
           dimensions  are  as  follows:-
Length  45 
ft.  11  in. 
       31 
ft.  2  in. 
Hoight 
15 
ft. 
9 
in. 
Thickness  of  walls 
6  ft. 
7 
in. 
ff  If 
roof 
6  ft. 
7 
in. 
Total  concrete 
730  cu. 
yd. 
a- nro:::. 
Reinforcement 
36  tons. 
t! 
The  reinfo rcem6nt,  consisting  of  3/4  in.  diameter  b .. rs,  is  buil t-Ui)  in  the 
form  of  a  grillage,  bars  running  in        directions,  and  forming  cubes  of 
10  in.  side  (Sheet  2).  One  re--,ort  suggested  that  tho  reinforcGment  VIaS  built-
u;  0:1  t:1U  site  and  fixed  bodily  in  sections.  The  ado:.,tir;n  cf  this  frothod  is 
         unlikely  because  of  weight t  difficulty  of           in  wi th  otht.-r  bars 
and  fixing  the  distributing  bars.  The  more  conv\.;nti  ncd,  m0thod  of  6recting 
tho  stoL:l  bar  by  bar  is  the  most  likely  used.  The  mii1ii.;um  concrete  cever  over 
reinforcement  is  in. 
Tho  underside  of  the  rc'of  is             witl;.  R.S.Js.  having  their  lowor 
flush  with  the  finished  coneret'e.  The  sizes  arc  %  in.  deep  across, 
the  entrE.nce  1)& ssages  and     in.  deep  acri"'ss  the  :?orsonnel  quar'ters.  Th( 
R.S.Js.,  are  bolted           in  threes  (sheet  3)  and  are  about  12  in.  centre 
to  centre.  Steel  distance  tubes  are  fitted  on  the  ti0-bolts  to  fiy.  spacing 
botv8Gn  tho  R.S.Js.  It  is  probable  that  steel         in  narrow  widths  arc 
laid  on  tho  bottom          of  the  R.S.Js.  to  serve  as  shuttering  t,'  thE 
undersido  of  the  ceiling. 
Steel  doors,  operated  frr:;m  the  inside,  are  a              a  standard  fitting 
in  this  ty)e.  Each  door  closes  on  to  a  channel  section  embf:dded  in  the 
concrete.  The  thickness  of  the  doors  is  not  kno\\Tn. 
An  armoured  turret     :)rovided  as  shown  on       ..  t  1.  The  turret  h3.s 
visor  slits  and  the  observer  stands  on  the  platforlll  to  \,hich  is  fixed  the 
access  ladder.  Details  of  this         are  not  availablu. 
- 10  -
                                  
I 
APPEftJDlX  11 
......  " ... 
. :  ....   .  '. .'  , 
.  " 
.  .'       .. 
6'  1 .  ",  >                        .. 
. ; 
c  " 
.  , 
  .:  ,:' t.  . 
.. '  ,  '  .. 
.....  . 
"  : ..........  . 
..   
. -:  8' -:;" ..  " 
.. 
  ...  .,  .    -;::.  .... '. 
__  -. II    _  . 
+  .  ,.  2" 
:  .....     '{l' <I        _,_:
0 
      . 
-........ ,..- '  .. ,    :' 
.  . - ..'  ..   
.. '.", . ::  ....  :  ..    ....... -: -.. 
,  " 
                       ------------..-1 
AR.IILL&R.Y 
M  l.          
MAV.      A'6w 
     
'X()O 
                               
lYPb-    
, ", 
to. 
r 
,  . 
SCALE:.  '!J'OO 
            
b 
rD 
StO\ltl! 
I  .. 
4/  (:) 
.; :   ...' :: . 
    : "." 
100 p  - holQ     ___  _ 
.J 
b 
    
Sheet 
jJ 
Stove 
' ..         "._ 
;,-.(    r-- (.  .    
               ..           .:' .. '.  ,0 
_. '  '""         ... "."r>  .'  .. 
sr:-c... T'     A-A 
O.P.              
o.P. Torret 
wi th  v,'Sor  '51 its 
-
                                     
AI". I e  b/7" 
.TunG  A.l A$W 
Appencil)(.12  5heet  z. 
PLA". 
O.B  t;.                      TE:R  TVP&  502 
              
T 
App&ndlX 12  Sheet  3. 
       ___  I  ,lf1  .; ----------4" 
 
I 
t 
I 
I 
--;:.,. ...... -...... _-- _  ....... ---..... -.. --...   ..... _  .. --f      --..., ... -.......... " 
.  , 
,"  ' ... 
;  , 
I  6'' 
I,  (  \ 
    I 
5a.  ;  I 
I  I  I 
11. ,J ho/t.J  I 
:  '\  .: 
t  t  \  I 
" 
I 
 
:  Utitt
t 
  '-..  : 
I  'a.)  , 
:  - .....  '  O  .. P   ,..,.".. 
I  ".   , 
  l  I          4  t  f  / 
f  ;  :  :  I  ./ 
I  I  I    I    
.-.L _____ .. .--.. __ .J  .............. ____ ................... ___ ..  L ... _ L  _  ... _  ... _  ....... __    ________   
M            
        ... 
Q,p.  t.  E"R,\088 it. , )"faLJi:& --- IYP& 50.a 
         OF  R-U,. 
5. 
1   Ty :  c  L  40 I   
A  dra\"ing  of  this  B.B  cm.  or  10.5  cm.  A.A.  Gun  Em-,?lacGment  with  Shelt ' T 
for            is  given  at           13. 
A:  1: roxima t e  detai Is  are  as  f.o llows:-
Length 
44  ft.  4  in. 
\'!idth 
36  ft.  1  in. 
Height 
22  ft.  1  in. 
Height  above  ground 
7 
ft.  0  in. 
Thickness  of  walls 
6  ft. 
7 
in. 
II  IT 
roof 
6  ft. 
7 
in. 
Excavation  90r , 
cu.  yd.             
Total  concrete 
860  cu. 
yo._ 
n 
Height  of  reinforcement 
33 
tons. 
11
2.         L  402. 
-------
      is  a  2  cm.  A.A.  Gun                 wi th  ShtJltcr  fer  Detachment  and  a 
drt:.'t'ling  is  given  at  appendix  14.  Approximate  details  are;  as  fellows:--
Length 
v'lidth 
Height 
Max.  height  above  ground 
Thickness  of  walls 
II  "roof 
Excavation 
Total  concrete 
         of  reinforcemont 
31  ft.  11  in. 
31  ft.  11  in. 
20  ft.  5  in. 
7  ft.  0  in. 
6  ft.  7  in. 
6  ft.  7  in. 
530  'Cu.  yd. 
560  cu,  yd, 
25  tons. 
If 
II 
A  drat:; ing  of  this  Heavy  A._A..  Batt ery  Command  ?ost  is  shown  at  arynendix  15. 
             dEtails  are  as  fol1ows:-
Length  62  ft.  4  in. 
"Tidth  (excluding  annexe)  48  ft.  4  in. 
Max.  width  63 
ft.  6  i11. 
lliax.  height  above  ground  level 
7 
ft. 
g 
in. 
Roof  level  abov8  ground 
3 
ft. 
3 
in.  (a: ;  rox) 
Thickness  of  walls 
6  ft. 
7 
in. 
"  " 
roof 
6  ft. 
7 
in. 
Excavaticn 
2200  cu.  yd.  a: I:  )l"' C x. 
Total  concrete 
210(1 
cu.  yd. 
II 
Height  of  reinforcement 
75 
tons. 
Ir 
:  ", ..  :  ..... 
- .',  .. 
000.    .. 
..  .  82 
- - r -','.  :. eO.    
    
1:--
  It 
!O  t 
PLAN 
APPE:ND1X  1:5 
/It. 
J 
-0 
        
.. 
    
  
S('ALE:.  Y.aso 
... 
          
c 
, 
o  of.  .., 
  u" 
ROOF  PLAN 
     liON  A-A 
:  -. 
     
      
8 .. 8c.m.  oR105<.m.  A.A.E.MPLACE.ME"'T                       L401 
APPl;J\JDtx  14 
     R.OOF  PLAH 
5&:c..TION  A-A 
2,cm.  A.A.              WIT"           - TYPE.  L402 
R..QCF  PLAIi 
A 
SCAL!:  '12.50 
APPENDIX 15 
                                 
 
               
. .  . 
  .0  .  ___        
  .,., .  (J    *      ""' ..  -., 
         
UEAVY,  A. A.       COMMAND                L 400 
6. 
- !:LLBO:CDS. 
---...--..------
1.  Tobruk-stand  58d. 
A  dra\'Ting  of  this  is  given  at  a:opendix  16. 
Length 
':Tidth 
Cvera11  height 
Concrete 
Reinforcemt;nt 
'Earth  over  roof 
12  ft.  1  in. 
9  ft.  11  in. 
9  ft.  In  in. 
15  cu.  yd  .  aJ'r0':. 
3/ g  in.  or  -l  in.  diamet,er  bars  at 
8  in.  s:)acing  a",):rrox. 
1  ft.  0  in.  E:t:  '-)rox. 
     oun,nti ty  and  d:i.sT)osi tion       the  reinforcemont  is  not  known.  This 
        is  designed  for     A.A./M.G.  the  biuod  of        is  provided  with 
rollers  tc  traverse  in  the  channel  shown  at  det':dl  'e'  on  the  drawing. 
     tY1e,  is  a  heavier  and  larger          of  that  described  abovb.  It 
hc,s  been  SE'8n  built  intc  sea  walls  and  is  usually  about  12  f0et  in  front  of 
the             shelter.  In  one  instance  the  com:nunic', tiCl  trench  was  revetted 
in  timber.  Plate  1  shows  one  of  these  :pillboxes  1.1  a  coastal  area. 
In  cO!rrl>arison  wi th  ty:')e  5Bd              16)  thls              has  the  fo 110'l'li!12 
di:nensions:-
Least  diameter  of  circular          
3 
ft.  6  i  :;.1  . 
Iieight,  fleor  to 
tt  II 
4 
.rt. 
11  in  
Thickness  of  concrete  (r8"":)o rt ed)  1  ft.  S  In. 
..  ight,  rear  comJ?artment 
(  'I) 
3 
ft. 
'Z; 
"'" 
FilII  details  of  this  type  are  not  available.  RI.!)ort:-:  state  that  an 
ordinary  mild  st\3el  door  is            frem       communioatiOrl trench  and  9.8 
raij.1.  enters  through  the  weapon  eperture  all  ammuni tiC::l  h  8  to  be  stacked  on 
duckboards.  This  latter  disadvantage  will  a:'Jply  also  to  '!'obruk-stand  5Bd. 
3.             
Ti:is  tY.ge  is  very  similar  to  the  Tobruk-stand  58d.  ',et  is  most  commonl;! 
to  be  found  in  the  ISIGNY  area.  A  drawing  of  this  ty')O  is  gi Yen  at           
17.  It  'V1i}1  be  noted  that  it  differs  very  Ii ttle  from  'e  5Bd;  the  main 
differences  being:-
(i) 
(i1) 
There  is  no  guid.e  rail  in  the  aperture  to  t:-t1::e  the  of  the 
bi":Jod  mounting. 
The  M.G.  mounting  is  a  wooden  }J"11e  a'bout  3  ft.  3  in.  fixed 
centrally  to  the  floor.  On  tou  of  the  'l)ole          is  a  small 
':100den  nlatform  \'ihich  can  be  turned  through  360"'.  The  bi:'1od 
mounting  of  the  lvI.G.  is  set  on  this  :glatfcr:n. 
information  available  of  the       mounting  is  insufficient  to  determine 
whether  tbe  gun  can  engage  all  grl'und  targets;  it  is'l'che,ble  that  the 
)il.lbox  W1S  designed  l1rimarily  fer  an  A.A.  re 1a.  .  ;;  'l    I' .  ' .. 
Rciniol'cement.  if  any.  is  eX:Jected  to  be  light.                 
J  I  -l, 
One  S011rce  indicates  that  this  pillbox  can  be  modified  to  take  a  small 
turret  having  M.G.  and  A.Tk.  gWlS  coaxially  mOWlted.  lJ:here  is  no  reason 
to  di .-bel.iove  this  story  since  a  number  of  turrGts  from  lh'onch  tanks  are 
being  used,  narticularly  in  coastal  areas
t 
for  this          
4.                  
Sketchos  of  this  tYT"e  are  given  at          IV.  The  dimensions  shown 
on  the  dra\'ling  are  alJproximate  only.  This  is                similar  to  the 
IIR=-_ngstancl
ll 
previou.sly  described,  with  tank  turret.  T'lis  pillbox  may  be 
fitted  '-lith  a  Renault  35  tank  turret. 
      tank  turrets,  which  are  armed  with  an  A.Tk.  t,'1J.n  u,nci.        
          are  of  a  small  type.  The  base  of  the  turret  is  bolted  to  a  circulg,r 
metal  ::>late  '.lhioh  is  traversed  by  hand  by  means  of  a  \<lh081  O?:l.  a  rail  buil t 
tnto  the  circumference  0  f  the  circular  a:nerture.  The  a::c  of  fire  is  ")60
0
 
The  oart:l  covering  over  the  roof  a:'):pears  to  be  about  3  ft.  thick. 
5.  Tam::  Turret s 
A  number  of+  pillboxes  have  been  r'::l"Iorted  fitted 'l;lith  turrets.  These 
turrets are           of  French  origin  and  a  recent  gr("unct  :)hotograJ)h  shows'a 
Renault  35  tank  turret  fitted  in  the  reof  of  -9,n  underGround           The 
turret  is  the  only           of  the  structure  which  :')rcj ects  above  ground 
levol  and,  not  be tng  of  dimensions,  may  be                     to  the 
c.:tsual  observer. 
- 13  -
                                                   
APP&I4DIX  " 
I 
     ------....  , --s  s              
        a--+:l1"+li41 
PLAN 
,  .  .:           
t ..  r 
    : 
t  :JII4Nf) 
   
-to 
2./4 
: .  -.     
"       "  '". 
       ':.         
  "  .. ,  ...  ,,. 
 ,'e  _.,:  ._:.   j)   
. '  ... tit....  -
UNDeRGROUND  PILLBOX  FOR  AA/MG. 
 10          
        AIIN 
TQB&UK.- \TAND.  TVPE:  S8d 
A 
APPt.NDIX  17 
., 
<:> ' 
,',  ") 
',.I?  :_, 
<II'  _",' 
c 
,  "     .,;:JI # 
1  4 
.,  .. 
(  ;,  .  t 
PLAN 
SCALE- 1J4  1NCl-t  TO  1 foOO T 
             P'LLBOX  FOR        
"   
           -"  TYPI::  R'NGST AND 
M.'.10         
7 .... n  fZ.  4"S  "IW 
T 
  n 
62.. 
Mo'.  10 t1/7
0 
",.lttV     1taN. 
         18 
    
7.  ABOVE  GR01T::JD  PIL::BOXJJS 
1. 
   
1'1 
                       of  a  large  pillbox  wi tlIJ. 
        1.::,  les  arE; t  arrparently,  designed  for 
and  it  is  O)rob:--ble  that  this  ::Jarticu.lar  pillbox  is  of 
n'l:JOer  of  this  type  t.xist  and  it  is  noteworthy  thn,t 
into  sr::8.-"!,'nlls  bear  a  general  resemblance  to  these. 
Constructional  details  are  not  available,  the 
give  the  'earance  of  very  solid  constru.ction. 
and.  3, 
.A 
nstruct!::,d 
8.             
1.     o,?ho                . :i;\ h:l      .  [::,                 U 
It  l,'lil1  be  noted  that       Germans  Tlr6vide  IDc:1)holos                            ..          
J:'  --     '#      :':I',.;iJIr  ,  ...  ''f?       ..  "  .' . 
entrancos  of  shelters  by  small  arms  fire.  A-p:,)roximate  det:tils  of  a           
I00:}hole  are  sho\'/n  at  appendix  19. 
It  is  jrobab1e       these            can  be  closed  by  a  sliding  plate 
because  }l"'ovision  aynears  to  be  Inado  for  metal  guides  OJ].  the  internal  face. 
The        ..  ;ing  should  be  taken  as  indicative  rather  than  accnrate.  The 
thickness  of  the  loophole  plate  may  be  1  - in.,  this  dimension  is, 
houever,  very  uncertain. 
- 15  -
APPEI\IOlX  19 
r--- ---------, 
I  j-----------,  I 
i           i 
I  -;lj1   
I  r---         .        I 
I  I  ..  '  --- - I 
I  "--__ ..,.1--__  -_-' 
   ___________________ J 
Nt ,. 10 b/72:S 
          
E:XIERNAL  VU;W 
GE.RMAN  TYPICAL          
(APPROXIMA1F;           ONLY) 
4  1 
       A  A 
UNCLASSIFIED