Page:United States Statutes at Large Volume 47 Part 2.djvu/696

 2300 Frame. Frame modulus. INTERNATIONAL LOAD LINE CONVENTION. JULY 5, 1930. For intermediate lengths, the value of f is determined by inter- polation. This formula applies where L does not exceed 600 feet; B is between ~+5 and ~+20, both inclusive, andi;sis betwean 10 and 13.5, both inclusive. Frame. - For the purpose of the frame modulus, the frame is regarded as composed of a frame angle and a reverse angle each of the same size and thickness. Frame Mod'lllus. -The modulus~of the midship frame below the lowest tier of beams is the moment of inertia. I of the frame section about tho neutral axis divided by the distance y measured from the neutral axia to the extremity of the frame section, calculated without deduction for rivet and bolt holes. The modulus is measured in inch units. The required frame modulus is expressed by s(d -l?~O+ f,), where- 8 is the frame spacing in inches. t is the vertical distance in feet measured at amidships from the top of the keel to a point midway between the top of the inner bottom at side and the top of the heel bracket (see Figure 2); where there is no double bottom, t is measured to a point midway between the top of the Hoor at centre and the top of the Hoor at side. fl is a coefficient depending on H, which, in ships fitted with double bottoms, is the vertical distance in feet from the middle of the beam bracket of the lowest tier of beams at side to a point midway between the top of the inner bottom at side and the top of the heel bracket (see Figure 2). Where there is no double bottom, H is measured to a point midway between the top of the Hoor at centre and the top of the Hoor at side. Where the frame obtains additional strength from the form of the ship, due allowance is made in the value of fl'