Alexandria University

Faculty of engineering

Naval Architecture & Marine engineering department

3rd year

Supervisor:
Dr. Adel Banawan Eng. Mina

Edited by:
Mahmoud gamal soliman odah

Sec (3)

No (77)

Summary:
 Resistance is a force which faces the ship during her motion, so to
allow the ship to move we must overcome this force. So it is important to calculate
this force to make it possible to calculate the effective power which is required to
choose the suitable power plant to push the ship in the water.

Ship total resistance may be classified into; underwater resistance, and above water
resistance.

The above water resistance is the resistance forces of wind acting on the above water
part of the ship. So its magnitude depends on the wind speed and direction, as well as
the shape of the above water area. So its value is very small and amounting to about
1-2% of the resistance.

The underwater resistance may be classified into still water resistance and rough
water resistance.

Acknowledgments:
In preparing this paper, I owe to my friends Ahmed Abdelhakim, Ahmed Shawky,
and, Ahmed Elsaid, I owe to my supervisor. Dr. Adel Banawan, eng. Mina. I owe also
to my university. They have challenged my advice, revised it, and made it more
precise.

Contents:
1. Over view
2. Main dimensions
3. Ratios
4. Coefficients
5. other parameters
6. Still water resistance
 At low speeds
 At high speeds
7. Rough water resistance
8. Shallow water resistance
9. Calculating residuary resistance using Guldhammer and
Harvald method:

Over view:
 Still water resistance

Frictional Residuary
resistance resistance

Wave making
resistance

Eddy making
resistance
Fig 1 shows the classification of still water resistance

Main dimensions:
Lwl T B LCB ∆ ∇ Rudder AM A℘ A BT
aft area
m m m m tons M3 M2 M2 M2 M2
173.76 7.993 24.8 2.524 21099.9 20585.268 32.3 194.1089 3139.019 5.9463

Ratios:
B L L3
L B ∇
0.1427 7 254.855

Coefficients:
Cb CM C℘ CP
0.59 0.9792 0.7284 0.6103

Other parameters:
V MAX rb hB d ν
Knots m m M 2 /S
38.91 1.3758 2.67 -0.9 1.16*10−6
Still water resistance:

C t=( 1+ k ) C f +C A +C w

Rt =0.5 ρS V 2∗C t

B A
(
Sbare =L ( 2T +B ) √ C M 0.453+ 0.4425C b−0.2862C M −0.003467
T )
+ 0.3696 C℘ +2.38 BT =4877.386 M 2
Cb

S= Sbare +rudder area=4909.686 M 2

Cb∗B 2
k =19( )
L

k =0.134729088

C A=0.006( LWL +100)−0.16−0.00205

C A=¿ 0.000394

0.075
Cf = 2
( log10 Rn −2 )
V ∗L
Rn =
ν

V
FN =
√ gL
At low speeds:
F N ≤ 0.4
λ
d
m2 (cos 2
)
m1 F N FN
Rw =ΔC 1 C 2 C 3 e e
1.0796
T
C 1=2223105C 4 3.7861 ( )
B
( 90−I E )−1.3757

B
C 4=
L

C 4=0.1427
 3
B 6.8 ( T A−T F )
I E =125.67 −162.25 C P2 +234.32C P3 +0.1551 LCB+
L T ( )
I E =¿11.1551

C 1=¿1.012158692
0.5
A BT ∗r b

C 2=e
−1.89
[ BT (rb +i) ]
i=T F −h B−0.4464 r b

i=4.70884288

C 2=0.8558539505

0.8 A BT
C 3=1−
BT C M

C 3=¿0.9754922239
3
L ∇ B
m1=0.01404 −1.7525 √ −4.7932 −C5
T L L

C 5=8.0798 C P−13.8673 C P2 +6.9844 C P3

C 5=1.353669183

m 1=-3.179625477

m 2=0.4 C 6 e−0.034 F N −3.29

C 6=-1.69385

L
λ=1.446 C P−0.03
B

λ =0.6723002516

At intermediate speeds:
0.4 < F N <0.55

R wF =0.55−R wF =0.4
Rw =R wF =0.4 + ( 10 F N −4 ) (
N N
)
N
1.5

F N =0.55
 λ
d
m2 (cos 2
)
m1 F N FN
Rw =ΔC 1 C 2 C 3 e e

∇ 2.0098 L 1.4069
−1.3346
C 1=6919.3 C M ( ) ( −2)
L3 B

C 1=1.000567791

B 0.3269 T 0.6054
m 1=−7.2035( ) ( )
L B

m 1=-1.920656481

m2=0.4 C 6 e−0.034 F N −3.29

m 2=-0.0247733528

Rw F N =0.4=12.77813224KN Rw F N =0.55=666.9388566KN

V Rn FN m2 Rw Cw Cf Rt Ct
1 1.5E+08 0.024220 -0.0252202 9.12E-36 3.62419E-39 0.00196661 6.606494062 0.002625569
9
2 3E+08 0.048441 -0.0251994 1.58E-17 1.57445E-21 0.001788042 24.38657027 0.002422943
8
3 4.49E+08 0.072662 -0.0251787 4.28E-11 1.88863E-15 0.001694637 52.469573 0.002316954
8
4 5.99E+08 0.096883 -0.025158 9.42E-08 2.34012E-12 0.001632735 90.45130709 0.002246711
7
5 7.49E+08 0.121104 -0.0251373 1.05E-05 1.67158E-10 0.001587025 138.0674314 0.002194844
6
6 8.99E+08 0.145325 -0.0251166 0.000255 2.81115E-09 0.001551088 195.1234304 0.002154068
5
7 1.05E+09 0.169546 -0.0250959 0.002709 2.19708E-08 0.001521648 261.4681162 0.00212068
4
8 1.2E+09 0.193767 -0.0250752 0.015733 9.76986E-08 0.001496817 336.9842181 0.00209258
3
9 1.35E+09 0.217988 -0.0250546 0.064808 3.17976E-07 0.001475416 421.5911013 0.002068516
3
1 1.5E+09 0.242209 -0.025034 0.198953 7.90683E-07 0.001456659 515.2461869 0.002047704
0 2
1 1.65E+09 0.266430 -0.0250134 0.526227 1.72838E-06 0.001439998 617.9771302 0.002029735
1 1
1 1.8E+09 0.290651 -0.0249928 1.131041 3.12154E-06 0.001425035 729.79682 0.00201415
2
1 1.95E+09 0.314871 -0.0249722 2.16101 5.08186E-06 0.001411476 850.7885574 0.002000725
3 9
1 2.1E+09 0.339092 -0.0249516 3.858761 7.82428E-06 0.001399094 981.1366139 0.001989417
4 8
1 2.25E+09 0.363313 -0.0249311 6.490623 1.14645E-05 0.001387713 1121.053966 0.001980142
5 8
1 2.4E+09 0.387534 -0.0249106 10.29598 1.59838E-05 0.001377191 1270.730899 0.001972723
6 7
1 2.55E+09 0.411755 64.04514 8.80726E-05 0.001367416 1478.892299 0.00203372
7 6
1 2.7E+09 0.435976 169.6743 0.000208125 0.001358296 1747.432093 0.002143422
8 5
1 2.85E+09 0.460197 275.3034 0.00030308 0.001349752 2024.430831 0.002228682
9 4
2 3E+09 0.484418 380.9326 0.000378478 0.00134172 2309.851516 0.002294967
0 4

2500

2000

1500

1000

500

0
0 5 10 15 20 25

Fig 2 shows the total still water resistance variation with respect to the ship's velocity

Rough water resistance:

This is due to the sea waves encountered by the ship. Its value depends on the
conditions of the sea and may amount to 25-35% for service in the north Atlantic, and
about 15-20% for service in the Mediterranean Sea.

Shallow water resistance:

When the ship moves through shallow water, she will be affected by two main effects;
back flow effect, and wave retardation effect.

h
Shallow water effects become pronounced when ≤ 3.
T

So we will consider that the depth of water which we will make calculations is h=3T

√ A m =0.581
h
1.72
( 1+k )shallow=( 1+ k )deep +0.644 ( T )
h
 ( 1+k )shallow=1.232056978

V Lw Fnh Vi / V Vi Vh Rf Ra Rw Rt
1 0.640 0.0652 1 1 0.960123 4.58784 0.91389 9.12E-36 6.566388
2 2 8 8
2 2.560 0.13040 1 2 1.920252 16.6807 3.65561 1.58E-17 24.20723
7 1 5 3 5
3 5.761 0.19560 1 3 2.880378 35.5659 8.22513 4.28E-11 52.04436
5 1 8 4
4 10.24 0.26080 1 4 3.840505 60.9126 14.6224 9.42E-08 89.67032
3 1 5 6
5 16.00 0.32600 0.999999993 4.99999996 4.800631 92.5047 22.8476 1.05E-05 136.8187
4 2 6 2 1
6 23.04 0.39120 0.999997889 5.99998733 5.760745 130.182 32.9004 0.00025 193.2926
6 2 7 3 2 5
7 31.36 0.45640 0.999932367 6.99952657 6.720429 173.799 44.7752 0.00270 258.9088
8 2 2 2 5 3 9
8 40.97 0.52160 0.999358296 7.99486636 7.676081 223.049 58.4148 0.01573 333.24
3 6 1 3 3
9 51.85 0.58680 0.997001804 8.97301624 8.615228 277.019 73.5829 0.06480 414.9518
3 3 4 6 9 8
1 64.01 0.65200 0.990987796 9.90987795 9.514734 333.824 89.7505 0.19895 501.2399
0 6 4 8 2 5 3
1 77.46 0.71720 0.979722647 10.7769491 10.34723 390.806 106.143 0.52622 588.1647
1 4 2 2 2 7
1 92.18 0.78240 0.962584136 11.5510096 11.09042 445.223 121.938 1.13104 671.6101
2 3 4 3 8 5 4 1
1 108.1 0.84760 0.939995721 12.2199443 11.73268 494.926 136.470 2.16101 748.4089
3 9 5 7 9 2 6
1 125.4 0.91280 0.913075843 12.7830618 12.27335 538.678 149.338 3.85876 816.8787
4 7 5 3 1
1 144.0 0.97800 0.883201325 13.2480198 12.71977 576.113 160.399 6.49062 876.6948
5 4 5 7 2 7 3 3
1 163.8 1.04320 0.851685656 13.6269704 13.08361 607.497 169.706 10.2959 928.4746
6 8 6 9 2 8 8 8
1 185.0 1.10840 0.819614633 13.9334487 13.37787 633.451 177.426 64.0451 1021.92
7 1 6 6 8 2 4
1 207.4 1.17360 0.787801401 14.1804252 13.61499 654.738 183.771 169.674 1160.121
8 1 6 2 8 1 9 3
1 231.1 1.23880 0.756807759 14.3793474 13.80598 672.123 188.963 275.303 1292.361
9 7 3 9 1 9 4
2 256.0 1.30400 0.726991681 14.5398336 13.96007 686.305 193.205 380.932 1419.705
0 7 7 1 6 1 4 6
2500

2000

1500

1000

500

0
0 5 10 15 20 25

Rt Rf Rt shallow
Fig 3 shows the total ship resistance in shallow water variation with respect to ship's
velocity.

Calculating residuary resistance using Guldhammer and Harvald

method:
L
1 =6.34
∇ 3

B
=3.1
T

δ 103 C r B
3

T
3
10 Cr =10 Cr ↓ B +
=2.5
δ
B T
−2.5 ( )
T

δ 103 Cr
=0.16
B
δ
T

3 3 δ 103 Cr
10 Cr =10 Cr ↓ LCB standard + ( LCB−LCB standard )
δLCB

Fn 103 Cr ↓ B 103 Cr ↓ B LCB standard δ 103 Cr 103 Cr

=2.5
T T
δLCB
0.145326 0.4 0.0384
0.169546 0.5 0.048
0.193767 0.6 0.0576 1.4 0 0.0576
0.217988 0.75 0.072 0.5 0.02 0.11248
0.242209 0.9 0.0864 1 0.12 0.26928
0.26643 1 0.096
0.290651 1.8 0.1728
0.314872 2.2 0.2112
0.339093 2.4 0.2304
0.363314 3 0.288
0.387535 3.8 0.3648
0.411756 6.2 0.5952
0.435977 8.2 0.7872
0.460197
0.484418