928 



HYDRODYNAMICS IN SHIP DESIGN 



Sec. X4.3 



TABLE X4.C — Correspondinq Values of Taylor or Speed-Length Quotient and Froude Number 

 For this tabulation the corresponding values have been taken as V/y/^ = 0.2978F/v'i and V/y/L = 3.S5SV/\/gL 



number of values in the past, varying from 6080 

 to 6080.3 ft. Only recently a new international 

 ratio has been adopted, to be given presently. 

 Still another example is the ratio between speed 

 in knots and speed in miles per hour; the latter 

 value is still used for motorboats in many quarters. 

 In 1954 a new International Nautical Mile was 

 adopted by the Defense Department of the 

 United States. This has a length of 6,076.10333 ft 

 or 1,852 meters, indicating a conversion ratio of 

 3.280833 ft per meter, or 39.3699996 in per meter. 

 The U. S. legal conversion ratio is 39.370000 in 

 per meter. A speed of 1 International Nautical 

 Mile per hour is equivalent to a speed of 1.6878 

 ft per sec, 1.15077 geographical or statute mi 

 per hr, and 0.51444 meter per sec. 



However, when the calculations embodied in 

 the text of Volume II of the present book were 

 made, prior to 1954, the nautical mile approved 

 for use in the U. S. Navy had a length of 6,080.20 

 ft. This corresponds to a speed of 1.6889 ft per 

 sec, 0.51478 meter per sec, and 1.1516 mi per hr. 

 These values were used throughout Parts 3 and 4, 

 expecially in the conversion diagrams of Figs. 

 X4.A through X4.F of Sec. X4.4. Other ratios 

 between English units of measurement are 

 indicated on those diagrams. 



A list of corresponding values of speeds, in ft 

 per sec, meters per sec, kt, and mi per hr, from 1 

 through 100 kt, is given in Table X4.b. These 

 figures, carried to only two significant figures 

 beyond the decimal point, were kindly furnished 



Fig. X4.A Conversion Factors for Length, 

 Adapted from O. W. Eshbach 



Fig. X4.B Conversion Factors for Volume 



