OCIMF_Mooring_Equipment_Guidelines_(Second_Edition)

Appendix D

Example oj Force Predictions jor Use

with Hand Calculation Procedures

Problem:

Determine wind and current force predictions for use witb the hand calculation procedure for a

250,000 dwt tanker for the conditions listed below.

Wind load calculations

Step 1: Determine the vessel's characteristics.

Vessel particulars for a 250 kdwl tanker in a fully loaded condition are

AI. (Longitudinal or Bro adside Wind Area) = .)l r rn'

Ar(Transverse or Head-on Wind Area) = 818 m^1

Step 2: Obtain wind coefficient at Ow = 1500

Cx", = -0. 73 Figure 2.4

C YA •. = + 0.19 Figure 2.3

C YF" = + 0.13 Figure 2.3

Slep 3: Compute wind forces from equations

where:

FrAW

Pw

= Cxw(~) V~Ar

7600

= C~w(7~~) V~AL

v w = 60 knots

= (_ 0.73)(1.223)(60)1(818)

7600

-346 kN

FyAw = (+0.19)(~·:n(60)"(3225) +346 kN

Fyp." = (+0.13)(~-:)(60)2(3225) = +243 kN