Sec. 5S.7 



RUNNING-ATTITUDE DIAGRAMS 



331 



appreciable until the water depth approaches or 

 is less than the beam of the planing form. In 

 view of the known performance of displacement- 

 type vessels under similar circumstances it is 

 not surprising that the drag and the trimming 

 moment about the trailing edge of the planing 

 form also increase with diminishing depth of 

 water. Other features accompanying these changes 

 are described by K. W. Christopher [NACA 

 Tech. Note 3642, Apr 1956]. 



58.7 References to Published Data. As is 

 the case with quantitative experimental or ob- 

 served resistance data in shallow water, the 

 greater part of the pubhshed information appears 

 in the older technical literature. However, all of 

 it together by no means covers the needs of the 

 marine architect and ship operator of today 

 (1955). Some of the available references follow: 



(1) Yarrow, A. F., "Past Torpedo Boats," Cassier's 



Mag., Jul 1897, Vol. XII, p. 294 



(2) Anderson, M. A., and Gillmor, H. G., U. S. torpedo- 



boats Talhot and Gwin (both old), ASNE, May 

 1898, Vol. X, pp. 493-501. These vessels were 

 99.5 ft long by 12 ft wide by 3.81 ft mean draft 

 (2.1 ft forward and 5.54 ft aft). The change of 

 trim at speeds of about 21 kt "amounted to about 

 41 inches (3.41 ft)." This corresponded to a T, of 

 21/V'9a5 = 2.10, Fn = 0.625, and a trim by 

 the stern of about 1.95 deg. 



The displacement was 45.75 tons and the dis- 

 placement-length quotient 46.4. Cb was 0.413, 

 Cx was 0.743, and Cw 0.659. From these data, 

 Cp was 0.556. 



(3) Gillmor, H. G., and Anderson, M. A., "The U. S. 



Torpedo Boat Morris (old)," ASNE, May 1898, 



Vol. X, pp. .'502-508. For this ve.sael, L„l was 

 138.5 ft, Bx was 15.0 ft, and H (mean) was 4.25 ft 

 (2.75 ft forward and 5.75 ft aft). The trial displace- 

 ment was 98 tons, with a displacement-length 

 quotient of 36.88. Cb was 0.425, Cx was 0.755, and 

 CwL was 0.687. Cp , from the foregoing, was 0.563. 



At a speed of 24 lit the change of trim was about 

 5 inch es, or 4.17 ft. At this speed, T, = 24/ 

 V138.5 = 2.04; F„ = 0.608. The trim by the 

 stern was about 1.72 deg. 



On page 507 of the reference it says of the Morris 

 that "she traveled on the back slope of a wave 

 with a normal disturbance of the surface of the 

 water." 



(4) White, Sir W. H., MNA, 1900, pp. 466-467, 475-477. 



For the Yarrow 80-ft torpedoboat mentioned in 

 this reference, at a T, of 2.07, F„ of 0.616, the 

 trim by the stern was about 2.5 deg. 



(5) Durand, W. F., RPS, 1903, pp. 121-123 



(6) Saunders, H. E., and Pitre, A. S., "FuU-Scale Trials 



on a Destroyer," SNAME, 1933. Table 6 on p. 251 

 gives the trim data for the U. S. destroyer Hamilton 

 (DD 141) for a range of speeds from 20 to 35.6 kt. 



(7) Davidson, K. S. M., PNA, 1939, Vol. II, pp. 107-108 



(8) Havelock, T. H., "Note on the Sinkage of a Ship at 



Low Speeds," Zeit. fiir Ang. Math. Mech., Aug 

 1939, pp. 202-205 



(9) Taylor, D. W., S and P, 1943, Figs. 21-25, p. 24; 



Figs. 84-93, p. 73 



(10) Van Lammeren, W. P. A., Troost, L., and Koning, 



J. G., RPSS, 1948, p. 88 



(11) Sund, E., "On the Effects of Different Turbulence- 



Exciters on B.S.R.A. 0.75 Block Models Made to 

 Various Scales," Norwegian Ship Model Basin 

 Rep. 11, Aug 1951, esp. pp. 3, 4, 12, 13, and Fig. 

 12 on p. 23 



(12) Davies, D. G., "Changes in Draft in Shoal Water," 



SNAME, Great Lakes Sect., Apr 1955; abstracted 

 in SNAME Bull., Jul 1955, Vol. X, No. 2, p. 39. 



