Question re: "Voyaging Under Power"

Greetings all,

I just finished reading "Voyaging Under Power" and have a question regarding the math the author uses, particularly that found in the "Mathematical Supplement" in Chapter 5.

He introduces two factors, F1 and F2. F1 is a function of Displacement in long tons, and F2 is (I think) a function of S/L. F1 x F2 = the shaft horsepower at a given speed.

My question is: what are these two factors? The book tells us to use the graphs provided, where the factor is on the Y axis and given term is on the X, but it would seem easier (and certainly more accurate) to use the actual equations to determine the factors.

I would appreciate any guidance you might have to offer. Also, I am looking for some books on basic naval architecture. Any suggestions would be greatly appreciated.

Thanks.

Craig

 

"but it would seem easier (and certainly more accurate) to use the actual equations to determine the factors."

If you read the publication date you will see it was before computers made difficult calculations easy.

(First edition ,,,second edition is a bastardized edition to sell Krogens)

The adverage lay person only needs the RESULTS of the graph , hardly the math behind the formula.

FAST FRED