BunkerCal
cul
ati
ons
Bunkeral
socal
cul
atef
orknowi
nghowmuchdai
l
yconsumpt
ionsofengi
ne.
Fuelconsumpti
onsorbunkertakenisalway
sinMet
ricTonne(MT)onshi
p.Act
uall
yFuel
Consumpt i
onsI
sHowMuchf uelisconsumedandi
tiscal
culat
edi
nMTnotinKil
ograms(KG)
.
WhyWet
akeBunkeri
nMet
ri
cTonne?
I
tistakeninMet r
ictonnebecauseVol
umeofthefuel
usedonshipchangeswithchangein
temperat
ure.AndItisnotpossibl
etomeasur
etheweightoff
uel
usedphy si
cal
l
y .That
’swhywe
usedmetrictonneforfuel
oil
.
Bunker
ingCal
cul
ati
onsFor
mul
a
Act
uall
y,wear
emeasur
ingi
tswei
ght
.so,
basi
cfor
mul
aweknowi
s,Mass(
kg)=Vol
ume(
m^3)
/Densi
ty(Kg/
m^3)
so,
Mass=Vol
ume/Densi
ty
Uni
tforMass=kg,
vol
ume+m^
3anddensi
ty=kg/
m^3
Asi
havealr
eadytol
dy ouwhywetakebunkeri
nMT.So,
for
mul
aforcal
cul
ati
onsi
s,Mass(i
n
MT)=Volume(inm^ 3)/Densi
ty(tonne/m^3)
Mass=Vol
ume/densi
ty(
v/d)
.
Uni
tsar
e,Massi
nmet
ri
ctonne,
vol
umei
nm^
3anddensi
tyi
nMt
/m^
3
Not
e:-Densi
tyusedforf
uel i
scall
edcorr
ecteddensi
ty.Asweknowt
hedensi
tyoff
uel
change
wi
thchangeoftemperat
ure.so,
densit
yisatthatt
emper at
ure.
Cor
rect
eddensi
ty:
-Iti
sdensi
tyoff
uel
oil
att
het
emper
atur
eoft
ankorbar
ge.
Not
e:-uni
tofdensi
tyi
skg/
m^3andMT=1000kg.
wi
thf
ormul
amassv
olume*densi
tyi
nki
l
ogr
am andwheni
tisdi
vi
dedwegeti
tinMet
ri
cTonne
(MT).
HowToConv
ertMTI
ntoM^
3
Vol
ume(
m^3)=Mass(
MT)/Densi
ty
Uset
heabov
efor
mul
atoconv
ertMTi
ntoM^
3.
Cor
rect
edDensi
ty
Whati
scor
rect
eddensi
ty?
Cor
rect
eddensi
tyoff
uel
oil
att
het
emper
atur
eoft
ankorbar
ge.
WhatI
sTheFor
mul
aOfCor
rect
edDensi
ty?
Cor
rectedDensi
tyatt
1temper
atur
e=Densi
tyoff
uel
oil
at15Degr
eecel
cius*[1-{t
1-
15)
*0.00064}
]
Densi
tyoff
uel
oil
at15degr
eecel
ciusi
sment
ioni
nbunkerdel
i
ver
ynot
es(
BDN)
.
Tst
andsf
ort
het
emp.ofoi
li
nthebunkert
anki
nthedegr
eecel
cius.
0.
00064i
nthef
ormul
aisbunkercor
rect
ionf
act
or.
v
olumeofoi
li
nnm^
3.
HowToCal
cul
ateTheVol
ume(
M^3)
Vol
umeoffuel
oil
kepti
nat
anki
scal
cul
atedbyabookcal
l
edsoundi
ngBookwhi
chi
sav
ail
abl
e
i
nEngi
neroom.
I
nsoundi
ngbook, v
olumeoffuel
ismenti
onaccor
dingtohei
ghtfr
om bot
tom .Tofi
ndHeight
(CM )
wetakesoundingoft
ankwit
hthehel
pofsoundingt
ape.So,wegetthevol
umeoffueloi
l.
Forapar
ti
cul
art
ank,
asoundi
ngt
abl
eispr
ovi
dedCal
cul
atet
hev
olumebyI
ncl
udi
ngt
ri
m.
I
nsoundingtabl
e,atparti
cul
arsoundi
ngdept
hincm v
olumeoff
uel
oil
isment
ionev
enkeel
,
tri
m byaheadandt r
im byaster
n.
I
nsoundingt
abl
ether
eisdepthgapof5cmsandyougett
hesoundi
ngi
nbet
weent
het
wo
dept
h,t
hentocal
cul
atesoundi
nguseuni
tar
ymeyt
hods.
BunkerCal
cul
ati
onsPr
ocedur
eSt
epBySt
ep
Letust
akeaexampl
eint
erm off
uel
oil
consumpt
ionssot
haty
oucaneasi
l
ycal
cul
atebunker
.
Iam pr
ovi
dingaf
igur
eofsoundi
ngt
abl
ebel
ow.
Assumei t
akeasoundi
ngofheav
yfueloi
lwitht
hehel
pofsoundi
ngtabl
eorgetaheighton
soundingt
ape894cmsandyourshi
pistr
im by0.
5meter
sbyasternatt
emperat
ureof50
degreecel
cius.
Seet
hef
igur
e,y
ougetadensi
tyoff
uel
in294.
35cubi
cmet
ersatshi
p0.
5tr
im byast
ern.
Now,
wehav
evol
umeoff
uel
oil
=294.
35cm^
3
Densi
tyoff
uel
at50degr
eecel
i
us=cor
rect
eddensi
tyoff
uel
at50degr
ee?
uset
hef
ormul
aforofcor
rect
eddensi
ty.
cor
rect
eddensi
ty=Densi
tyoff
uel
oil
at15Degr
eecel
cius*[1-{t
1-15)
*0.
00064}
]
Densi
tyat15degr
eecel
ciusi
sment
ioni
nbunkerdel
i
ver
ynot
es.l
etus,
Densi
tyat15degr
eecel
cius=0.
9909
Temeper
atur
eoff
uel
=50degr
eecel
cius
Now,
Cor
rect
eddensi
tyoff
uel
at50degr
eecel
cius=0.
9909[1-
0.00064(
50-
15)
}
=0.
9909[
1-0.
00064(
50-
15)
]
=0.
9682
Mass=v
olume*densi
ty
=294.
35*
0.9682
=284.
98967kg
=284.
98967/
1000=0.
28498967MT
Thi
sisdet
ail
sexpl
ainsofbunkercal
cul
ati
ons.
BunkerCal
cul
ati
onsAnot
herExampl
e.
Consi
derwehav
etotake285MTofDi
esel
Oil
inat
ank1.Capaci
tyoft
anki
s400m^
3att
ri
m of
0.
50m.Tankisful
l
yempty.
NowwegetdensityofDiesel
oilat15degr
eecelci
usf
rom bunkerdel
i
ver
ynot
es.l
etusassume,
densi
tyofdi
esel
oilat15degreecelci
us=0.9909.
Temper
atur
eofdi
esel
moi
latt
het
imeofpumpi
ng=n50degr
eecel
cius.
Now,
Cor
rect
edDensi
tyat50degr
eecel
cius=Dat15degr
ee[1–0.
000645(T-
15)
]
Put
ti
ngal
lthei
nfor
mat
ion,
youwi
l
lget
,
=0.
9682kg/m^
3
Vol
ume=mass/cor
rect
eddensi
ty
=285/0.
9682
=294.
35m^
3
asment
ionedabov
e,v
olumeoft
ank=400m^
3.
Asi havet
otake285MTofdieseloi
landthei
rvol
umeweget=294.
35m^
3andcapaci
tyof
tankis400m^3.so,
wecantakeinthetank.
Not
e:-I
ftheTanktherei
ssomef uelassume100m^ 3.Asweknowf uelinthet
ankfi
ll
edupto
85%ofcapaci
ty.I
nthiscondi
ti
ons,wef i
l
lnotf
il
ltheal
ldiesel
inonetank.Whentankgetf
il
led
85%thenwehav etoopenthefi
ll
i
ngv al
veofanothert
ank.
85%of400m^
3=340m^
3
Them 340m^3–294.35m^3=45.
65m^ 3offuelneedtot
ransf
eri
nanot
hert
ank.Foranot
her
tankwehavet
ofol
lowthesamepr
oceduret
of i
ndv ol
umeoffuel
.
Summar
yOfBunkerCal
cul
ati
ons
1.
Findv
olumeoff
uel
oil
byusi
ngsoundi
ngt
abl
einm^
3
2.
Cal
cul
ateCor
rect
eddensi
tyatPar
ti
cul
arTemper
atur
e.Uni
tofDensi
tyi
sKg/M^
3.
3.
Cal
cul
ateMassbyusi
ngf
ormul
amass=densi
ty*v
olume.
Not
e:-Youwi
l
lgett
hismassi
nkg.Di
vi
dei
tby1000,
youwi
l
lgeti
nMet
ri
cTonne(
MT)
Thi
sisaboutcal
cul
ati
ngQuant
it
yoff
uel
inmet
ri
cav
ail
abl
eint
ank
