where:

A=1.813 (σm/ΔσA) 2;

σm=design primary membrane stress;

ΔσA=(allowable dynamic membrane stress for double amplitude at probability level Q=10−8) 53.9 MPa (7821 psi) for ferritic and martensitic steels and 24.5 MPa (3555 psi) for 5083-0 aluminum;

C=a characteristic tank dimension that is the greatest of h, 0.75b, or 0.45 l;

where:

h=the height of the tank or the dimension in the vessel's vertical direction, in meters;

b=the width of the tank or the dimension in the vessel's transverse direction; in meters; and

l=the length of the tank or the dimension in the vessel's longitudinal direction, in meters; and

ρ=the specific gravity of the cargo.