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2. CALCULATING BERTHING ENERGY (Continued)
b) Container Ships
c) Ore Carriers
d) Tankers
2.4 OTHER FACTORS TO CONSIDER
Now that the fender design has been narrowed down to a couple of
options, the designer must look at a number of other considerations and
decide whether or not they are important in his design.
The following are a few common considerations:
a) Fender Performance Characteristics
Not only must the fender design absorb the required berthing energy, but
the designer must also consider the reaction loads that this system will
impart to the structure. The reaction loads and their location may have a
significant impact on the structure design. Generally the reaction loads are
not a problem with gravity structures, however, with pile supported piers,
the reaction loads may become critical to the design and may influence
such things as batter pile locations and the rebar design.
b) Fender Spacing
Fender spacing along the pier face is an important design consideration.
Here the designer is trying to maximize protective pier coverage while mini-
mizing the fendering costs.
There are three standard methods.
i) Fender spacing of not more than 1/10 the length of the vessel.
ii) Using the vessel's geometry along with the above configuration,
the following formula can be developed:
2l = 2 r 2 - (r - h)2
Where:
r = the bent radius of the ship's hull at the contact line.
h = the compressed height of the fenders at their rated deflection.
Some typical bow bent radius values are shown below. Exact values from
the vessel should be used.
10,000 175 25.6 15.8 9.8 14,030 1.96 15.77
20,000 200 27.3 16.8 10.4 27,940 1.62 25.95
25,000 213 30.1 16.3 10.5 34,860 1.54 30.78
30,000 290 32.0 19.8 10.3 41,740 1.60 38.29
35,000 265 32.8 20.5 11.6 48,600 1.59 44.31
40,000 279 32.5 22.8 11.0 55,430 1.49 47.36
50,000 290 32.4 24.2 11.3 69,000 1.43 56.58
Tonnage(D.W.T.)Length(in meters)Width(in meters)Height(in meters)Loaded Draft(in meters)DisplacementTonnage (DT)Virtual MassCoefficientBerthing Energy(Tonne-M)*
2,500 83 11.9 6.4 5.4 3,290 1.59 3.0
5,000 105 14.9 8.0 6.5 6,570 1.54 5.8
10,000 140 18.5 10.5 8.0 13,100 1.55 11.64
15,000 160 21.0 12.0 9.0 19,600 1.53 17.19
20,000 175 23.5 13.0 9.7 26,090 1.51 22.60
30,000 195 26.6 14.4 10.5 38,970 1.44 32.18
40,000 210 29.7 15.9 11.1 51,740 1.40 41.53
50,000 222 32.5 17.0 11.8 64,390 1.40 51.69
60,000 238 34.0 17.6 12.3 76,940 1.38 60.88
80,000 259 38.0 19.1 13.1 101,690 1.35 78.72
100,000 278 41.0 21.0 15.2 126,000 1.41 101.87
150,000 310 45.5 25.0 17.6 184,840 1.42 150.50
Tonnage(D.W.T.)Length(in meters)Width(in meters)Height(in meters)Loaded Draft(in meters)DisplacementTonnage (DT)Virtual MassCoefficientBerthing Energy(Tonne-M)*
1,000 58 9.4 4.5 4.2 1,360 1.60 1.25
2,500 82 12.0 6.1 55 3,400 1.59 3.10
5,000 102 15.0 7.7 6.5 6,790 1.51 5.88
8,000 126 15.7 9.0 7.4 10,600 1.52 9.24
10,000 140 19.0 9.8 7.9 13,540 1.52 11.80
15,000 163 20.0 11.2 8.6 20,250 1.48 17.19
20,000 175 23.5 12.3 9.6 26,930 1.48 22.85
30,000 195 27.0 14.1 10.7 40,190 1.45 33.41
40,000 213 29.6 15.2 11.8 53,300 1.45 44.31
50,000 224 32.0 16.6 12.3 66,270 1.41 53.58
60,000 236 34.0 17.7 12.7 79,100 1.39 63.04
70,000 248 35.8 18.6 13.5 91,790 1.40 73.69
85,000 260 38.1 18.7 14.0 110,550 1.37 86.84
100,000 285 40.1 21.1 14.8 129,000 1.39 102.820
150,000 300 46.1 24.3 17.0 188,200 1.37 147.84
Tonnage(D.W.T.)Length(in meters)Width(in meters)Height(in meters)Loaded Draft(in meters)DisplacementTonnage (DT)Virtual MassCoefficientBe
rthing Energy
(Tonn
e-M)*
r
D
C B
l
2l
h
E
o
1°
Load line 209 230 240 240
Upper Deck 155 200 360 240
5°
Load line 54 70 85 110
Upper Deck 53 70 100 85
10° Load line 44 60 70 75
Upper Deck 40 65 55 60
ApproachAngle ContactLine General Cargo*10,000 DWTGeneral Cargo*30,000 DWTOre Carrier*35,000 DWTTanker*50,000 DWT
*These values are for general guidelines only.
They should be checked using actual site conditions.
*Units = Meters