Sec. 48.14 



WIND-WAVE AND SHIP-WAVE DATA 



177 



Wove Lenqth Lw, ft 



Fig. 48.J Graph Indicating Characteristics of the Zimmermann Wave 



Department in Washington. Incidentally, these 

 instructions extend the Beaufort scale numbers 

 through 17, as follows: 



Wind Force 15, Velocity 90 through 99 kt 



16 100 through 108 kt 



17 109 through 118 kt. 



A most useful supplementary table, partly 

 pictorial, is published in "All Hands," Bureau of 

 Naval Personnel Information Bulletin, July 1954, 

 pp. 32-33. However, the wind-velocity values for 

 Beaufort-scale numbers do not correspond with 

 those mentioned in the preceding paragraph. 



48.14 Wind- Wave Patterns and Profiles by 

 Modem Methods. Modern techniques of photo- 

 grammetry render the plotting and sectioning of 

 wave contours and profiles a vastly less laborious 

 and much quicker process than was the case 



two decades ago, when the stereoscopic wave 

 photographs taken on the German M.S. San Fran- 

 cisco were analyzed [Weinblum, G., and Block, 

 W., "Stereophotogrammetrische Wellenaufnah- 

 men (Stereophotogrammetric Wave Photo- 

 graphs)," STG, 1936, Vol. 37, pp. 214-250 and 

 259-276; TMB Transl. 204, Nov 1949]. For 

 information, Fig. 48. K shows profiles through 

 waves that were photographed and analyzed as a 

 part of the open-sea test project on this vessel. 



One modern method involves two synchronized 

 cameras which are mounted on a large ship with 

 theii" optical axes in transverse planes parallel to 

 each other and parallel to the baseplane of the 

 ship. Their lenses are equidistant from the plane 

 of sj^mmetrj^ so that their negatives lie in a given 

 plane parallel to the ship centerplane. The camera 

 axes are far enough apart, in a fore-and-aft direc- 

 tion, so that good stereoscopic vision is obtained 



