USFD TEST

BOOKLET
AS PER MANUAL FOR ULTRASONIC TESTING OF RAILS
AND WELDS - Revised 2022

Published by:
Indian Railway Institute of Civil Engineering, Pune. NOV-2022
A. Schedule of equipment and accessories checking, Calibration and
sensitivity setting:
a) Characteristics checking : - Once in a month
b) Calibration setting : - Once in a week
c) Sensitivity setting : - Once in three days
d) Temperature variation setting : - Once in a month
e) Visual examination of machine, tools and equipment: - Daily
B. Procedure for ultrasonic testing of rails (Para 5.1 of USFD Manual)
1. Before Testing
f) Check the battery condition before the start of work. Only fully
charged battery is to be used.
g) Check the proper functioning of all controls in the electronic unit
i.e., depth range, gain, reject etc.
h) Check the proper functioning of trolleys and probes.
i) Check the junction box, water outlet, connecting cable, and probe
contact and ensure smooth movement of trolley wheels.
j) Maintain a gap of 0.2 mm between the probing face and probe
shoe.
k) Check probe alignment by keeping the rail tester on the rails.
l) Calibrate the instrument weekly as per the procedure given in Para
4.1.1(b) of the USFD manual.
m) Set the equipment for proper sensitivity as per para 4.1.1(c) of the
USFD Manual.
n) Check the Characteristics of machine and probe as per IS Code
12666-2018 and ensure their performance is within the
permissible limits as mentioned in RDSO Specifications of machine.
2. During Testing
a) Conduct the test as per the procedure mentioned in chapter 6 of
the USFD manual.
b) Maintain proper alignment of all probes during testing to avoid
false echoes.
c) Ensure an adequate supply of water for coupling.
d) Check the proper functioning of 70° probes by touching the probe
bottom with your fingers. A noise pattern should appear on the
screen.
e) Look out for a back wall echo corresponding to the normal probe
throughout the testing.
f) Lift the machine at crossings/change of rail table height at joints to
protect the probes.
g) Mark the locations found defective as per classification.
3. After testing
a) Enter proper testing records, observations, echo patterns and
amplitude of defects in TMS. The details should be supplemented
with A-scan recorded.
b) Charge the battery after every day’s work.
c) Data of B-scan should be kept preserved as permanent records for
last 3 recordings of the section and in case of fracture the same
should be analyzed and action taken accordingly.
CHART SHOWING THE CODE OF PROCEDURE FOR USFD TESTING
Probe Location USFD
Sensitivity Rejection criteria Classification Type of defect Manual
Used & setting of (Flaw Peak Pattern) to be Detected
Freq. testing para
Through Rail testing
No back echo before or after Any horizontal
the appearance of bolt-hole IMR defect in rail
echo with flaw echo with or XXX head, web or
without multiple foot of length
equal to the
distance
Drop in back echo before or between the
after the appearance of bolt IMR rail end and
hole echo with flaw echo with XXX first bolt hole
or without multiple and connected
with the
railhead
100% back Within No back echo between bolt Any horizontal
0° Wall signal Fish holes echo, with flaw echo IMR defect Para 6.3
height from with or without multiples XXX connecting Annexure-
4 MHz Plated both bolt holes IIA Sr. No.1
Rail bottom
area Any defect
originating
from bolt
holes and
No back echo before or after progressing at
the appearance of bolt hole IMR an angle
echo with or without flaw XXX towards the
echo head web
junction or
web foot
junction
 Probe Location USFD
Sensitivity Rejection criteria Classification Type of defect Manual
Used & setting of (Flaw Peak Pattern) to be Detected
Freq. testing para
Through Rail testing
No back echo with flaw echo IMR Any horizontal
(shifting/without shifting) for XXX defect
any horizontal length
progressing at
an angle in a
No back echo and no flaw IMR vertical plane in
echo XXX the rail at the
Outside following
Fish location*
plated
area No back echo with flaw echo IMR Any horizontal
(shifting/without shifting) for XXX defect
100% back Horizontal Length ≥ 20 mm
progressing at
Wall signal Para 6.3
0° height from No back echo with or an angle in a Annexure-
Rail bottom without shifting flaw echo for OBS vertical plane in IIA Sr. No.1
4 MHz X
Horizontal Length < 20 mm the rail other
than above

Side
probing In case of partial/complete
on rail loss of back echo from rail
head top, side Probing to be done IMR Vertical
Gauge/ and if any flaw echo found XXX longitudinal
Non- with or without multiples in split (piping)
Gauge any length during side
face probing.
side
 Probe Location USFD
Sensitivity Rejection criteria Classification Type of defect Manual
Used & setting of (Flaw Peak Pattern) to be Detected
Freq. testing para
Through Rail testing
For For ‘D’ Marked
Non ‘D’ Rails on a
Marked Rails double line &
60% height on double line all rails on a
from 12mm ø single line
Dia. hole in Any transverse
rail head 25 defect in the rail
mm from rail i) H ≥ 30% i) H ≥ 0 IMR
XXX head at the Para 6.3
70° top ii) V ≥ 20% ii) V≥ 20%
Central following Annexure-IIA
(Additional location*
2 MHz Sr. No. 2 & 3
gain of 10db Rail head i) H≥50% i) H≥50% IMR
for D marked ii) V≥60% ii) V≥20% XXX Any transverse
rails or all
i) 30%≤H<50% i) H< 50% defect in the rail
rails on Single
ii) V≥20% or ii) V≥20% OBS head other than
line section. X
i) H≥50% above
ii) 20%≤V<60%
Railhead Any transverse
60% Height on gauge defect in the rail
70° head on gauge Para 6.3
2 MHz from 5 mm ø face side i) H≥ 15% IMR
GF & NGF XXX face side/non- Annexure-
flat bottom & non- ii) V≥ 20%
side gauge face at IIA Sr. No. 4
hole gauge the following
face side location*
 Probe Location USFD
Sensitivity Rejection criteria Classification Type of defect Manual
Used & setting of (Flaw Peak Pattern) to be Detected
Freq. testing para
Through Rail testing
Railhead i) H ≥ 30% IMR
70° 60% Height on gauge ii) V ≥ 60% XXX Any transverse
Para 6.3
2 MHz from 5 mm ø face side i) 15% ≤ H < 30% OBS defect in the
GF & NGF Annexure-
flat bottom & non- ii) V ≥ 20% X rail head other
side IIA Sr. No. 4
hole gauge i) H ≥ 30% OBS than above
face side ii) 20% ≤ V < 60% X
Any transverse
100% with defect in the
respect to Rail head Loss of signal height equal to IMR
rail head, at
45° reflecting with or more than 20% XXX the following Para 6.3
Two probes signal scabs, locations*
(One Pair) wheel Annexure-
received Loss of signal height equal to IMR
mounted in from the burn on Any transverse IIA
or more than 80% XXX
the Test Rig opposite the top defect in the Sr. No. 5
face of the surface Loss of signal height equal to OBS Rail head other
rail head or more than 20% but less
than 80% X than above
Web, Any defect
37° 60% Height head-web Any moving signal observed Para 6.3
IMR originating from
2MHz from 5mm junction in web region (i.e. beyond 2.3 Annexure-
Centre div in horizontal scale) other XXX bolt holes and
saw cut on and than standard peak from bolt IIA
Probe progressing at an
bolt hole web- foot hole, bond wire hole etc. Sr. No. 6
junction. angle

Any sweeping signal on a horizontal baseline that does not extend Any transverse Note of
beyond 25% (i.e. 2.5 Div) from the left edge of the screen or vice versa GCC defect in rail head Annexure- IIA
 Probe Location USFD
Sensitivity Rejection criteria Classification Type of defect Manual
Used & setting of (Flaw Peak Pattern) to be Detected
Freq. testing para
Through Rail testing (Weld Defects)
Any horizontal
defect
progressing at an
No back echo with flaw echo, IMRW angle in a vertical
shifting or without shifting plane in the weld
100 % XXX
back wall at the following Para 6.5.1
0° signal location* Annexure- IIB
height Weld
4 MHz Sr. No. 1
from Rail Any horizontal
bottom defect
No back echo with flaw echo, OBSW progressing
shifting or without shifting transversely in
X the weld other
than above
i) H≥ 30% IMRW Any transverse
ii) V≥ 20% XXX defect
60% progressing at an
height from angle in a vertical
12mm Ø hole i) H≥ 50% IMRW Para 6.5.1
70° XXX plane in the weld
in Rail head at Weld ii) V≥ 60% Annexure- IIB
Centre 25mm depth Head at the following
2 MHz location* Sr. No. 2
from Rail top
i) 30%≤H<50% Any horizontal
ii) V≥20% or OBSW defect in the
i) H≥ 50% X weld head other
ii) 20%≤V<60% than above
 Probe Location USFD
Sensitivity Rejection criteria Classification Type of defect Manual
Used & setting of (Flaw Peak Pattern) to be Detected
Freq. testing para
Through Rail testing
Any transverse
defect progressing
60% height Weld at an angle in a
from 5 mm Head i) H≥ 15% IMRW
70° XXX vertical plane in
on the ii) V≥ 20%
2MHz Flat bottom weld at following
gauge Para 6.5.1
GF & hole location*
face Annexure-IIB
NGF side i) H≥ 30% IMRW
side ii) V≥ 60% XXX Any transverse Sr. No. 3
60% height Weld i) 15% ≤ H < 30% OBSW defect in the
from 5 mm Head on ii) V ≥ 20% X weld head other
Flat bottom the gauge i) H ≥ 30% OBSW than above
hole face side ii) 20% ≤ V < 60% X
SEJ Stock / Tongue testing
Any defects
45% height Web &
45° originating from
from 5x3mm Foot of Para
2 MHz V > 20% IMR bolt hole and
Hand
Cut in the Stock/
XXX machined edge of
11.8.4.4
bottom of tongue rail
probe SEJ Stock/ tongue
SEJ’s stock rail of SEJ
rail bottom
60% height Any transverse
70° from 5 mm ø Head of defect in the SEJ
2MHz
IMR Para
hole in rail SEJ Stock/ V > 20% XXX Stock/ tongue rail
Hand probe head at depth tongue rail head and gap 11.8.5.4
25 mm avoiding rail
Head, web
Any horizontal
0° 60 % height of and web- Any flaw peak of V > 20%
IMR defects in head,
4MHz Double back wall signal foot or
web and web-foot
Para
Crystal from Rail junction of Partial/complete loss of backwall XXX 11.8.6.4
junction of
Hand probe bottom SEJ Stock/ echo shall be classified as IMR.
stock/tongue rail
tongue rail
CHART SHOWING THE CODE OF PROCEDURE FOR AT WELD TESTING
Probe Type of USFD
Sensitivity Location Rejection criteria
Used & Classification defect to be Manual
setting of testing (Flaw Peak Pattern)
Freq. Detected para
Initial Weld Testing
i) 30% ≤ V from head region. DFWN
ii) 20% ≤ V from web or foot region. XXN
60% height
0° Porosity, Blow
from 3 mm Weld head & Periodical Weld Testing
2 MHz hole, Slag Para
dia. hole in up to neutral
Hand i) 40% ≤ V ≤ 60% from head region. inclusion in head 8.5.4
weld head 25 axis in Web
probe DFWO and up to mid of
mm from rail ii) 20% ≤ V ≤ 40% from the web or O the AT Weld
top foot.
i) V > 60% from weld head region DFWR
ii) V > 40% from the web or foot XX

Initial Weld Testing

i) V > 30% (Moving signal) DFWN Lack of fusion,
60% height XXN
70° ii) V > 10% (A bunch of Moving signal) porosity, blow
from 3 mm Para
2 MHz hole, slag
dia. hole in Weld head Periodical Weld Testing 8.6.2,
Hand inclusion and
weld head 25 8.6.4
Probe i) On vertical scale : Moving signal of DFWO crack in head of
mm from rail
40% or more and up to 60% O the AT weld
top
i) V > 60% (Moving signal ) DFWR
ii) A bunch of moving signal V >10% XX
Probe Type of USFD
Sensitivity Location Rejection criteria
Used & Classification defect to be Manual
setting of testing (Flaw Peak Pattern)
Freq. Detected para
Initial Weld Testing
DFWN Lack of fusion,
60% height V > 30% (Moving signal)
70° XXN porosity, blow
from 3 mm dia. Para
2 MHz hole, slag
hole in middle Weld flange Periodical Weld Testing 8.6.2,
Hand inclusion and
of the weld 8.6.4
Probe DFWO crack in foot of
flange 40% ≤ V ≤ 60% (Moving signal)
O the AT weld
DFWR
V > 60% (Moving signal)
XX
Initial Weld Testing Clustered
V ≥ 20% from bottom of the DFWN defects, micro
45°
Bottom weld foot XXN porosities and
2 MHz Para
Hand 60% height of the Periodical Weld Testing Halfmoon
8.7.1.4
from weld foot V ≥ 20% from bottom of the DFWR shaped defect at
probe
10x5x2 mm weld foot XX the bottom of
Halfmoon weld foot
cut in Initial Weld Testing Halfmoon
Pair of
bottom of V ≥ 20% from bottom of the DFWN shaped
70° Bottom
the weld weld foot XXN transverse Para
2 MHz of the
Periodical Weld Testing defects at the 8.8.4
side weld foot
V ≥ 20% from bottom of the DFWR bottom of
looking
weld foot XX weld
 Probe Type of USFD
Sensitivity Location Rejection criteria
Used & Classification defect to be Manual
setting of testing (Flaw Peak Pattern)
Freq. Detected para
Initial Weld Testing Vertically
100% with Head–web oriented defects
DFWN
Pair of 45° respect to junction, V ≥ 30% like lack of fusion
XXN
2 MHz signal complete located at head Para
(Tandem received web & up Periodical Weld Testing web junction, 8.7.2.4
rig) from bottom to web-foot DFWR complete web
of rail + 10 dB junction V ≥ 40% and upto web
XX
foot junction.

CHART SHOWING THE CODE OF PROCEDURE FOR FB WELD TESTING

Lack of fusion
Pair of 45° 60% height
Defective and oxide Para
2MHz (T/R from 5 mm ø Head of On vertical scale : Any flaw signal
weld inclusion in head 9.5.1.2
method) hole in head FBW
portion
Discontinuities
60% height
due to lack of
70° Hand from 5 mm Web and Defective Para
On vertical scale : Any flaw signal fusion and oxide
probe dia. hole in foot of weld 9.6.4
inclusions in web
web FBW
and foot portion
* Vulnerable Locations-
(i) Tunnel and tunnel approaches (100 m either side)
(ii) Major bridge and its approaches (100 m either side)
(iii) In the vicinity of hole near the weld (50 mm for old AT weld and 75 mm for new AT weld from the centre of
weld on either side of weld)
Note:
(i) Any defect or defects at any location which is detected by two or more probes and are considered to be classified as
OBS/OBSW based on peak pattern of individual probe, should be classified as IMR/IMRW and action shall be taken
accordingly as per para 6.4.
(ii) In case two or more OBS/OBSW defects are located within a distance of 4.0 meter from each other, such OBS/OBSW
defect shall be classified as IMR/IMRW and action shall be taken accordingly as per Para 6.4.

ACTION AFTER DETECTION OF DEFECTS:

Sr. Painting on both
Classification Interim action
No. faces of web/ head
XXX SSE/JE (P.way)/USFD shall impose a speed restriction of 30 Kmph or stricter
1 IMR/IMRW Three cross with immediately and to be continued till the flawed rail/weld is replaced.
red paint in web
X SSE/JE (P.way)/USFD to advise sectional SSE/JE (P.way) within 24 Hrs about the
2 OBS/OBSW One cross with flaw location. Keyman to watch during daily patrolling till it is joggled fish
red paint in web plated and joggled fish plate clamped within three days.
XXN SSE/JE/P.way shall protect the DFWN defect by joggle fish plate with two tight
3 DFWN Two Stars with N clamps immediately along with support on wooden block.
with red paint in web DFWN defect shall be removed within 1 month of detection.
SSE/JE (P.way)/USFD shall impose a speed restriction of 30 Kmph or stricter
immediately and communicate to sectional SSE/JE about the flaw location, who
shall ensure the following:
O
4 DFWO Protection of defective weld by joggled fish plates using a minimum of two tight
One circle with red
clamps immediately with a speed restriction of 30 Kmph. Speed restriction can
paint in head
be relaxed to normal after the protection of DFWO weld by joggled fish plates
with 2 far-end tight bolts (one on each side) with chamfering of holes, within 3
days. The joint is to be kept under observation.
 Sr. Painting on both
Classification Interim action
No. faces of web/ head
SSE/JE (P.way) USFD shall impose a speed restriction of 30Kmph or stricter
immediately and communicate to sectional SSE/JE about the flaw location who
will ensure the following: -
Protection of DFWR weld by joggled fish plates using a minimum of two tight
clamps immediately. SR of 30 Kmph can be relaxed to normal after providing
joggled fish plates with two far-end tight bolts one on each side with
champhering of holes. The DFWR weld shall be replaced within three months
of detection.
XX Adequate traffic block should be granted for the removal of DFWR welds. In
Two cross with case of non-removal within three months, a speed restriction of 75 Kmph for
5 DFWR
red paint in loaded goods trains and 100Kmph for passenger trains should be imposed.
head In case of the defective weld (DFWO/DFWR) on major bridges & bridge
approaches (100m on either side) and tunnel & on tunnel approaches (100m
on either side), the following action will be taken:
a) SSE/JE (P.way)/USFD shall impose a speed restriction of Kmph or stricter
immediately and to be continued till the defective weld is replaced. He should
communicate to sectional SSE/JE (P.way) about the flaw location who shall
ensure the following: -
i) Protection of defective weld using clamped joggled fish plate within 24 Hrs.
ii) The defective weld shall be replaced within 3 days of detection.

Note: A thermit welding done in situ shall be joggled fish plated with two clamps and supported on a
wooden block 300 to 450mm length until tested as good by USFD.
Frequency of Rail testing based on the need-based concept:
Testing frequency once in
Main line BG on CC+8+2t
Routes routes, falling in temp.
Route
having All Main line Zone IV and Zone III on track
GMT Routes structure with 52 kg
(90 UTS) rail
<2.5 5 years --
ALL MG Routes 2.5-5 3 years --
>5 2 years --
≤5 2 years 18 months
>5≤8 12 months 09 months
> 8 ≤ 12 9 months 6½ months
All BG Routes
(rail head centre > 12 ≤ 16 6 months 4½ months
and gauge face > 16 ≤ 24
corer/ non gauge 4 months 3 months
face corner > 24 ≤ 40 3 months 2½ months
testing) > 40 ≤ 60 2 months 1½ months
> 60 ≤ 80 1½ moths 1 months
>80 1 month 20 days
Reduced frequency period for rail testing:
I) For the rails rolled before April 99 – 15% of stipulate service life in terms of GMT
II) For the rails rolled in April 99 and later- 25% of stipulated service life in terms of GMT
Rail Assessed GMT service Assessed GMT service life
Gauge
Section life for T-12 72 UTS rails for T-12 90 UTS rails
800
60 kg 550
*(1000 for routes covered by rail grinding)
B.G.
52 kg 350 525
90 R 250 375
75 R 150 -
M.G.
60R 125 -
*For reduced frequency testing period, 800 GMT service life shall be considered for
60 kg (90 UTS) and 60 kg (R260) grade rails.
Note:
i) During reduced frequency period, rails are to be tested at passage of 40 GMT or
Eight (08) years, whichever is earlier.
ii)For other sections Principal Chief Engineer of the Railway may adopt a frequency
at his discretion.
Frequency of Weld testing In Main line of BG & MG routes based:
Sr.
No. Type of welds Type of testing Testing schedule
1 Conventional Every 40 GMT or 5 years
AT weld Periodic test whichever is earlier
2 Acceptance test Immediately after welding
(Within 1 Month)
3 20 GMT or 1 year whichever
Fist periodic test is earlier
5 Further tests Routes having
based on route GMT Frequency
GMT
6 >80 1 year
7 >60 ≤80 1½ years
8 SKV weld >45 ≤60 2 years
9 >30 ≤45 3 years
10 >15 ≤30 4 years
11 0-15 5 years

Note:
i. In case of welds on major bridges and bridge approaches (100 m either side)
and in tunnels and on tunnel approaches (100 m either side), the minimum
frequency of testing shall be once in a year.
ii. Due to unusually high weld failure or other abnormal development in some
sections, Principal Chief Engineer may order testing of welds early, as per need.
iii. Testing interval of USFD testing of defective welds should be reduced by 50%
of normal testing interval of AT welds as provided in the table above to avoid
fracture of defective welds.

Frequency of Weld testing for Loop lines:

Sr. No. Type of testing Testing schedule
1 Acceptance test Immediately after welding.
(Within 1 Month)
2 First periodic test After one year.
3 Further subsequent test Once in every five years for
passenger running loops.
Note:
(i) Not to be carried out for non-passenger running loops.
(ii) Due to unusually high weld failure or other abnormal development in some
sections, Principal Chief Engineer may order testing of AT weld for loop lines
early, as per need.