Page 366 - Practical Ship Design

Freeboard and Subdivision 323

(a) 0.3
=
Jmax 48 I Ls with
max value of 0.24
0.2
at Ls < 200 in
J,,
J I Jmex has max value
0.1 of 4.167 for Ls < 200
0
0 100 200 300 400 500
Ls in metres

Approximate number of compartments
Formulae:
6 If y < 1, F1 = f - (Y)~ I3
and F2 = (y)'- (y)'I 12
5 These formulae generally
apply to single
compartments
F1 4
and
If y > or = 1, F1 = y - 1/3
F2 3 andF2=(y)Z12-y/2+1/12
These formulae generally
apply to two or more
compartments

0 1 2 3 4
damaged compartment length
y = J I J,,=
rule maximum damage

1.5 E = 2 x non-dimensional distance from amidships
on Ls to centre of compartment
a=12+08E max12
F = 04 + 025 E(l 2 +a)

J' = J - E if E is positive (in the fore body)
- 2(LS/2-X1)
--
Ls
-1 0 +I J' = J + E if E is positive (in the aft body)
amidships ford
E - 2(LSI2-X2)
Ls
Fig. 11.5. Probabilistic subdivision of cargo ships. (a) J,,, versus L,. (b) F, and F2 versus J/J,,,,,.
(c) Factors a and F versus E.