17 re 15 14 13 IE II 10 9 8 7 6 5 4 



Fig. 6S.C Non-Dimensional Sheer Lines for Five Classes op Vessel 



broken lines for the tankers, provided the free- 

 board and the pitching depths forward and aft, 

 described in Part 6 of Volume III, are adequate. 



A factor to be considered on all craft which 

 are required to travel in waves in ballast condi- 

 tion, when trimmed well by the stern, is that 

 there should still be some residual sheer with 

 respect to the at-rest water surface when in this 

 attitude. Changes of trim due to loading alone 

 may at times reach 3 deg, corresponding to a 

 slope of 0.0524. 



68.5 Design of Abovewater Section Shapes; 

 Tumble Home; Compound Flare. The shape of 

 the abovewater sections of a seagoing ship is 

 governed partly by functional and utilitarian 

 reasons and partly by wavegoing requirements. 

 Design details pertaining to the latter are given 

 in Part 6 of Volume III. Factors of importance 

 in the former are: 



(a) Large deck area at the ends as well as amid- 



ships, for carrying bulky cargo items such as 

 miscellaneous vehicles, trucks and trailers, air- 

 planes being ferried, small yachts, boats, and the 

 hke 



(b) Large abovewater volume within the hull, 

 for accommodating passengers or for storing low- 

 density cargo or supplies 



(c) Small deck area and small abovewater volume, 

 for reducing top weights and lowering the CG 



(d) Recessed or tumble-home sides, for clearing 

 the abovewater portions of docks and other ships, 

 especially when the ship is subject to roll from 

 low swells or list from cargo handling and when 

 adequate facilities are not available for keeping 

 the ship breasted off. 



The combination of continuously curved surface 

 and near-surface waterlines with parallel level 

 lines in way of the passenger accommodations 

 well above the DWL is embodied to an almost 

 exaggerated extent in the Netherlands passenger 



