Compton Semiplaning 1986 method - Typo in the article?

[Vincent G]

I am trying to use the paper from Roger H. Compton 'Resistance of a Systematic Series of Semiplaning Transom-Stern Hulls' from Marine Technology Oct. 1986 (and also enclosed on SNAME small-craft CD-ROM). I know, this is corresponding to old fashion hull lines...

Based on model test results, a regression formula is given to compute residuary resistance coefficient Cr in function of Froude number Fn for both round bilge and hard-chine hulls.

An example is given in the article with vessel characteristics and the corresponding EHP from model test and difference with regression computation - showing good agreement - unfortunately, no detail of the computation is given.

Unfortunately, when using the regression method, I find Cr coefficients which are quiet different from what they should be.
I double-checked the maths manually, and my application of the method is correct.
I am now wondering if the regression coefficients given in the article are correct. Does anybody have any experience with this ?

The example model particulars are:
LOA 108.0ft
LPP 101.2ft
Ref draft 6.0ft
BWL 21.4ft
L/B 4.719
Disp. 163.2LT
LCG 4.47ft aft of amidship
WSA 2377ft2
LWL 101.7ft

From these particulars, I computed the following parameters needed by the regression formula:
LPP/BX 4.729 (I supposed that BX=BWL)
DLR 157.46
LCG/LPP .4558
Round Bilge

My results are:
Fn = { .1 .15 .2 .25 .3 .35 .4 .45 .5 .55 .6 }
CR = { .01324346406 .0130523335 .01355796833 .01564463618 .01876070302 .02054304344 .02177314384 .02635984895 .02779758948 .02411864564 .01987043872 }

Can somebody knowing the method check my results?
Do you have any correction that should be applied that I am not aware of?

Best regards

Vincent

[symfoni]

Hi Vincent
Did you find the typo?
I have the same problem…
LCG/LPP = 0.4558 ?????
I’m using LCG/LPP = 0.044, then later multiply it with 100 in the regression equation.

Apart form this we doing the same thing… And I can’t Implement the method in the same way as Compton in Fig.36 and Table 3.

Any Ideas, Anyone…?
/Anders