Page:United States Statutes at Large Volume 47 Part 2.djvu/694

 2298 Strenrth deot. Draught. INTERNATIONAL LOAD LINE CONVENTION. JULY 5, 1930. Strength Deck.- The strength deck is the uppel'Inost deck which is incorporated into and forms an integral part of the longitudinal girder within the half-length amidships. Depth f.o Strength Deck (Ds).- · The depth to strength deck is the vertical distance in feet amidships from the top of the keel to the top of the strength deck beam at side. Draught (d).- The draught is the vertical distance in feet amidships from the top of the keel to the centre of the disc. Longitudinal modn· Longitudinal Mod'lllus.-The longitudinal modulus y!. is the moment Ius. of inertia I of the midship section about the neutral axis divided by the distance y measured from the ne1.Jtral axis to the top of the strength deck beam at side, calculated in way of openings but without deduc- tions for rivet holes. Areas are measured in squarG inches and dis- tances in feet. Below the strength deck, all continuous longitudinal members other than such parts of under deck girders as are required entirely for supporting purposes, are included. Above the strength deck, the gun- wale angle bar and the extension of the sheerstrake are the only members included. ThA required longitudinal modulus for effective material is expressed by f.d.B ., where f is the factor obtained from the following table:- L. f. L. f. 100 1.80 360 9.40 120 2.00 380 10.30 140 2.35 400 11.20 160 2.70 420 12.15 180 3.15 440 13.10 200 3.60 460 14.15 220 4:20 480 15.15 240 4.80 500 16.25 260 5.45 520 17.35 280 6.20 540 18.45 300 6.95 560 19.60 320 7.70 580 20.80 340 8.55 600 22.00