Sec. 61.22 



PREDICTED BEHAVIOR IN CONFINED WATERS 



415 



shallow and restricted waters upon ship perform- 

 ance, as described and explained in Chaps. 18 

 and 35 of Volume I and in the preceding sections 

 of this chapter, the following items appear in 

 qualitative terms: 



(a) The draft below the still-water surface is 

 increased because of the deeper sinkage of the 

 ship in the intensified Bernoulli contour system 



(b) The changes of trim are augmented because 

 of the intensified Velox-wave system 



(c) The overall sinkage and trim is a function 

 of the position and slope of the ship on the surface 

 of a solitary wave of translation which may be 

 traveling near the ship 



(d) The pressure drag or resistance is increased 

 because of the constrictions imposed on the ship 

 velocity and pressure fields by the rigid boundaries 



(e) The slope drag or slope thrust encountered 

 is a function of the slope and the position of the 

 ship with respect to the solitary wave of trans- 

 lation 



(f) The slope drag may be sufficient, when it 

 changes sign and becomes a slope thrust, to 

 cause a decrease in total drag with an increase 

 in speed, at a point just above the critical speed 



(g) The friction drag is increased, partly by the 

 augmented rearward motion of the water past 

 the ship and partly by the thinning of the bound- 

 ary layer, with consequent increase in velocity 

 gradient in the laminar sublayer, when the clear- 

 ances between the ship and the rigid boundaries 

 become small 



(h) The ship vibration is generally intensified 

 and magnified in shallow water. 



61.22 Partial Bibliography on the Effects of 

 Confined Waters on Models and Ships. A 

 partial list of references follows on shallow- and 

 restricted-water effects and on the behavior of 

 ships in confined waters: 



(1) White, Sir William H., "Notes on Recent Experience 



with Some of H. M. Ships," INA, 1892, pp. 160-186 



(2) Rasmussen, A., "The Influence of the Depth of 



Water upon the Speed of Ships," Engineering, 

 London, 7 Sep 1894. This article is reprinted in 

 (5) following, pp. 18-20. 



(3) Laubeuf, M., "Influence de la Profondeur de I'Eau 



sur la Vitesse des Navires (Influence of the Depth 

 of Water on the Speed of Ships)," ATMA, 1897, 

 Vol. 8, pp. 207-213. A partial translation is avail- 

 able at the DTMB. 



(4) Paulus, Naval Constr., "Versuche zur Ermittlung des 



Einflusses der Wassertiefe auf die Geschwindigkeit 

 der Torpedoboote (Tests of the Effect of Water 



Depth on the Speed of Torpedoboats)," Zeit. der 

 Ver. Deutsch. Ing., 10 Dec 1904, pp. 1870-1878. 

 This paper contains records of trials of the German 

 torpcdoboat SI 19, including wave-prolile and 

 change-of-trim diagrams for a series of speeds. 



(5) Rasmussen, A., "Some Steam Trials of Danish 

 Ships," INA, 1899, pp. 12-26 and PI. V, describing 

 tests on the Danish torpedoboats Makrelen and 

 Sobjornen 



(0) Rota, G., "On the Influence of Depth of Water on 

 the Resistance of Ships," INA, 1900, pp. 239-248, 

 giving the results of tests on Italian torpedoboat 

 models 



(7) White, Sir William H., MNA, 1900, pp. 469-470 



(8) Haack, M., "Nouvelles Recherches sur la Resistance 



des Carenes et le jFonctionnement des Bateaux 

 (New Investigations on the Resistance of Hulls 

 and the Functioning of Ships)," ATMA, 1900, 

 Vol. 11, pp. 41-48. This is a discussion of shallow- 

 water performance, based upon the published data 

 of Captain Rasmussen and General Rota, in INA 

 for 1899 and 1900, respectively. 



(9) Schiitte, J., "Neuere Versuche fiber Schiffswider- 



stand in freiem Wasser (New Experiments on Ship 

 Resistance in Open Water)," Proc. Ninth Int. 

 Shipping Congr., Diisseldorf, 1902 



(10) Durand, W. F., RPS, 1903, pp. 110-119. Covers the 



"Increase of Resistance Due to Shallow Water or 

 to the Influence of Banks and Shoals." 



(11) Popper, S., INA, 1905, Part I, pp. 199-201 and Pis. 



L-LIII 



(12) Yarrow, H.; report on the trials of a Yarrow-built 



destroyer, INA, 1905, Part II, pp. 339-343, 

 349-358, and Pis. LXXIX-LXXXI 



(13) Marriner, W. W., INA, 1905, Part II, pp. 344-358 



and Pis. LXXXII, LXXXIII 



(14) Watts, Sir Philip, INA, 1908, pp. 69-70 



(15) Watts, Sir PhiUp, INA, 1909, pp. 176-178 and Pis. 



XV and XVI, reporting on trials of the British 

 destroyer Cossack. The pertinent data for the two 

 measured-mile courses on which this vessel was 

 run are: 



(a) Skelmorlie mile, depth h = 240 ft, critical 

 wave speed = 87.8 ft per sec or about 52 kt 



(b) Maplins mile, depth h = 45 ft, critical wave 

 speed = 38.05 ft per sec or about 22.5 kt. 



(16) Sadler, H. C, "The Resistance of Some Merchant 



Ship Types in Shallow Water," SNAME, 1911, 

 pp. 83-86 



(17) Baker, G. S., and Kent, J. L., "Effect of Form and 



Size on the Resistance of Ships," INA, 1913, 

 Part II, pp. 37-60 and Pis. Ill, IV. Fig. 5 on PI. 

 IV shows a 2-diml ship-shaped forebody in a 

 uniform stream parallel to the longitudinal axis, 

 and gives streamlines for the flow of the water 

 around this forebody and between two parallel 

 boundaries. The forebody was "shaped" by com- 

 bining 2-diml line sources and sinks with a uniform 

 stream parallel to the ship axis. 



(18) Taylor, D. W., "Relative Resistances of Some 



Models with Block Coefficient Constant and Other 

 Coefficients Varied," SNAME, 1913, pp. 1-8, 



