Code of Federal Regulations Title 46. Shipping § 46.172.090 Intact transverse stability

(a) Except as provided in paragraph (b) of this section, each tank barge must be shown by design calculations to have a righting arm curve with the following characteristics:

(b) If the vertical center of gravity of the cargo is below the weather deck at the side of the tank barge amidships, it must be shown by design calculations that the barge has at least the following metacentric height (GM) in feet (meters) in each condition of loading and operation:

where—

K=0.3 for river service.

K=0.4 for lakes, bays and sounds and Great Lakes summer service.

K=0.5 for ocean and Great Lakes winter service.

B=beam in feet (meters).

fe=effective freeboard in feet (meters).

(c) The effective freeboard is given by—

where—

f=the freeboard to the deck edge amidships in feet (meters).

fa=(1.25)(a/L)((2b/B)–1)(h);  or

fa=h, whichever is less.

where—

a=trunk length in feet (meters).

L=LOA in feet (meters)

b=breadth of a watertight trunk in feet (meters).

B=beam of the barge in feet (meters).

h=height of a watertight trunk in feet (meters).

d=draft of the barge in feet (meters).

(d) For the purpose of this section, downflooding angle means the static angle from the intersection of the vessel's centerline and waterline in calm water to the first opening that does not close watertight automatically.