The following formulae are given as guidance for the components
of acceleration due to ship's motions corresponding to a probability
level of 10-8 in the North Atlantic and apply to ships
with a length exceeding 50 m.Vertical acceleration as defined in 4.3.4.6
Transverse acceleration as defined in 4.3.4.6
Longitudinal acceleration as defined in 4.3.4.6
with:
|
A
|
= |
|
where:
|
L
o
|
= |
length of the ship for determination of scantlings as defined
in Recognized Standards (m) |
|
C
B
|
= |
block coefficient |
|
B
|
= |
greatest
moulded breadth of the ship (m) |
|
x
|
= |
longitudinal
distance (m) from amidships to the centre of gravity of the tank with
contents; x is positive forward of amidships, negative aft of amidships |
|
z
|
= |
vertical
distance (m) from the ship's actual waterline to the centre of gravity
of tank with contents; z is positive above and negative below the
waterline. |
|
a
o
|
= |
 where:
|
|
V
|
= |
service
speed (knots) |
|
K
|
= |
1
in general. For particular loading conditions and hull forms, determination
of K according to the formula below may be necessary.
|
|
K
|
= |
13GM/B,
where K ≥ 1.0 and GM = metacentric height (m).
|
|
a
x, a
y and a
z
|
= |
maximum dimensionless
accelerations (i.e. relative to the acceleration of gravity) in the
respective directions and they are considered as acting separately
for calculation purposes, a
z does not include
the component due to the static weight, a
y includes
the component due to the static weight in the transverse direction
due to rolling and a
x includes the component
due to the static weight in the longitudinal direction due to pitching.
|