870 



HYDRODYNAMICS IN SHIP DESIGN 



Sec. ISA 



(f) Cooling water intake scoop and discharge for 

 main condenser are not to be reproduced. 



The principal dimensions, form coefficients, 

 ratios, and design parameters for the ABC ship, 

 at this stage of the design, are listed for the 

 information and convenience of the Model Basin 

 staff in Table 78. a. A set of drawings ultimately 

 furnished the Model Basin, with their correspond- 

 ing figure numbers, is hsted in Table 78. b. 



A few words of explanation are inserted at this 

 pomt for the benefit of the reader who may have 

 noted shght numerical discrepancies here and 

 there in the tabulated data and in the text. For 

 example, the bare-hull volumes and displacements 

 for the transom-stern and arch-stern ABC 

 designs, as listed in Table 78.a, differ slightly 

 from those in Table 78. c. Any one who has de- 

 signed a ship, or a house, or a machine, appreciates 

 that the design is constantly developing, with 



TABLE 78.a — Principal Dimensions, Ratios, and 

 Coefficients for the ABC Design 

 These data apply to the design at the point where model 

 tests are requested. They are modified slightly in the 

 SNAME RD sheets. The figures given apply to the bare 

 hull, molded, at the stage in the design when they were 

 first furnished to the Taylor Model Basin. 



TABLE 78.b — List of Drawings Furnished to 



THE Model Basin in Connection With the 



Model-Test Program fob the ABC Ship 



Figure 

 in Part 4 



Title 



66. P Body Plan with Single-Skeg Transom Stern 

 66.Q Profile of Transom Stern with Single Skeg 

 67. A Designed Waterlines for Transom Stern and 



Arch Stern 

 67. B After Portions of Afterbody Waterlines for the 



Transom-Stern Hull 

 67.E Bow Profile, Bulb Bow, and Cutwater 

 67. L Afterbody Plan of Arch-Type Stern 

 67. M Afterbody Profile and Partial Fish-Eye View 



of Arch-Type Stem 

 67. W Section- Area Curves for Transom-Stern and 



Arch-Stern Designs 

 73.B Design of Cutwater 

 73. F Layout of Quadruple Strut Arms and Hub for 



the Arch-Stern Ship 

 73. N Structural Layout for RoU-Resisting Keels 

 74.K Details of Aftfoot, Propeller Aperture, Rudder 



Support, and Rudder for Transom-Stern 



Hull 

 74. L Vertical Centerplane Section Through Shaft, 



Propeller, and Strut Bearing Support of 



Arch-Stern Design 

 74. N Arrangement and Details of a Contra-Horn 



and Rudder for Transom-Stern Hull 



almost continual changes in dimensions and 

 characteristics. To make the illustrative examples 

 in Part 4 more realistic, the numerical data are 

 taken directly from the work sheets of the author 

 and his assistant, at appropriate stages in the 

 design. The reader mil, it is hoped, understand if 

 not all these discrepancies are specifically ac- 

 counted for. 



78.4 Use of Stock Model Propellers for First 

 Self-Propulsion Tests. Considerable time is 

 saved, to say nothing of expense, if the first self- 

 propelled tests of a model are conducted with an 

 available model propeller. At the tune of under- 

 taking the tests of the models for the ABC ship 

 (1953), the David Taylor Model Basin had a 

 stock of well over 3,000 propellers suitable for use 

 with ship models of conventional sizes. Other 

 large model basins performing self-propelled tests 

 are similarly equipped. Model propellers, imlike 

 to\ving model hulls, are almost never thrown 

 away. Model basin staff.s have sufficient index 

 information to enable the selection of a model 

 propeller on a basis of diameter, pitch-diameter 

 ratio, number of blades, mean-width ratio, blade- 

 thickness fraction, type of blade section, and so on. 



