Sec. 7r,.4 



DESIGN OF SPECIAL-PURPOSE CRAFT 



75b 



Arrow, designed by C. D. Moshei', reached the 

 unprecedented speed of 45 kt a few years later. 

 For displacement-type vessels to reach T, values 

 of 3.4 and 4.5 was remarkable, and still is, but 

 the useful loads carried by each were extremely 

 small. 



An early form of the German schnellboote (fast 

 boat), a displacement- type craft intended to 

 maintain high speed on the high seas in heavy 

 weather, is described and illustrated in Schiffbau 

 [26 Oct-2 Nov 1921, pp. 112-116]. A set of small- 

 scale lines of this round-bottom craft is included 

 in the article. During World War II the Germans 

 built and operated a considerable number of these 

 so-called S-boats of a later version [Rupp, L. A., 

 NavTechMisEu Rep. 338-45 of 23 Aug 1945; 

 Biiller, K., Handbuch der Werften, 1952, pp. 

 37-42]. The David Taylor Model Basin made 

 numerous tests following World War II of TMB 

 model 3993 representing some of these craft 

 [TMB Rep. 628 of Jan 1948 and other reports]. 



Although by no means cargo carriers in the 

 accepted sense of the term these craft did carry 

 an appreciable useful load, and they performed 

 admirably in such rough-water areas as the English 

 Channel and the North Sea. They may well 

 serve as the starting point for the development of 

 larger and faster versions, carrying larger pro- 

 portions of useful weight. 



76.4 Long, Narrow, Blunt-Ended Vessels; 

 Great Lakes Cargo Carriers. Limitations on 

 beam and draft imposed by canal locks, drydocks, 

 pier facilities at loading and unloading ports, and 

 shallow water along the route produce a ship form 

 that is abnormally elongated, especially if the 

 carrying capacity is high. The result is a series of 

 widely varying types, among which may be hsted 

 the American (freight) car float, the self-propelled 

 cargo-carrier of the Erie and other American 

 canals, the river steamer and its towed barges of 

 the large European rivers, and the bulk-cargo 

 carrier of the American Great Lakes. Only the 

 self-propelled craft are considered here; the others 

 are discussed in Part 5 of Volume III. 



In the past, these limitations have produced 

 box-like or block-shaped vessels, with the ends 

 whittled off just enough to make them manageable 

 in the confined waters in which they operated or 

 to enable them to be self-propelled with some 

 reasonable degree of efficiency. The Great Lakes 

 freighter has benefited from a great deal of 

 attention, devoted both to its construction as 

 well as its design. It is perhaps not strange, in 



view of the low speeds at which these vessels 

 formerly traveled, that the emphasis has been on 

 capacity and cargo handling rather than on hydro- 

 dynamics. R. Curr gives the lines of a Great Lakes 

 bulk ore carrier of a half-century ago [SNAME, 

 1908, PI. 87]. Fig. 76.A shows the fines of a World 

 War II design of some 40 years later, similar 

 to the design covered by SNAME Resistance 

 Data sheet 90. 



J. J. Henry gives a considerable amount of 

 statistical and other data on Great Lakes bulk 

 ore vessels in his paper "Modern Ore Carriers" 

 [SNAME, 1955, pp. 92-95], but here again the 

 emphasis is on features other than hydrodynamics. 

 Table 76. d lists five more vessel types and supplies 

 supplementary information on hull proportions 

 and features and form coefficients. Discrepancies 

 between the two tables are due generally to lack 

 of precise definition of the terms listed. 



The bibliography of 24 items at the end of the 

 Henry paper, a number of which apply to ocean- 

 going vessels with few draft and beam limitations, 

 is supplemented by the references which follow: 



(1) Babcock, W. I., "Longitudinal Bending Moments of 



Certain Lake Steamers," SNAME, 1905, pp. 187- 

 207 and Pis. 119-133. This paper, although 

 primarily structural, gives principal dimensions of 

 the Victory and the Elbert H. Gary. 



(2) Sadler, H. C, and Lindblad, A., "Stresses on Vessels 



of the Great Lakes Due to Waves of Varying 

 Lengths and Heights," SNAME, 1922, pp. 77-82. 

 The text and PI. 13 contain some data relating to 

 hydrodj'namio design. 



(3) Lindblad, A. F., "Some Features Affecting the 



Economy of the Lake Freighters," SNAME, 1923, 

 pp. 37-49 and PI. 9 



(4) Cross, A. W., SNAME, 1928, pp. 51-62 and Pis. 



41-51. The paper is built around a description of 

 the steamer Harry Coulby, having an Lb^l oi 

 615.2 ft, a S of 65 ft, a displacement of 19,092 long 

 tons and a speed of 11.3 kt. 



(5) Fisher, C. R., and Kennedy, A., Jr., "Turbine 



Electric Drive as Applied on the Great Lakes 

 Cargo Ships," SNAME, 1928, pp. 235-248 and 

 Pis. 135-138. This paper on propelling machinery 

 gives a considerable amount of hull design and ship 

 performance data on the steamer Carl D. Bradley. 



(6) Workman, J. C, "Shipping on the Great Lakes," 



SNAME, HT, 1943, pp. 363-376 



(7) Baier, L. A., "The Great Lakes Bulk Cargo Carrier; 



Design and Power," SNAME, Great Lakes Sect., 

 1947, Vol. 55, pp. 385-390. On p. 390 of this paper 

 the author gives a list of 25 references pertaining 

 to the Great Lakes bulk cargo carrier. 



(8) Mathews, S. T., "Resistance and Propulsion Tests on 



a Model of a Lake Freighter," Div. Mech. Eng., 

 Nat. Res. Council, Ottawa, Rep. MB-137, 3 Jul 

 1951 



