High Speed Boats. Center of Gravity

HSB Center of Gravity.

TAD,
Many thanks for you interesting additional support. I will use and try all your suggestions to see the best way to solve my doubts and concerns.
mvd535

 

The real problem is how to reach the l.c.g. position in a power boat...
Installing piercing devices or waterjets the l.c.g. will be far behind the l.w.l./2, only with submerged prop's it would be possible to have a marge in shiftimg weights.
For high speeed boats, + 40 knots, the l.c.g. is located btw. 34/36% of l.w.l.
The F.O. tanks are located near the l.c.g. in way to not modify the running trim when you have less fuel.
My own experience in designing high speed boats is that it is not always possible to reach the opt. l.c.g.......

 

HSB Center of Gravity.

To Ranchi Otto
This percentage between 34% to 36% of LWL, is measured:
1.- At rest LWL (static) ?
2.- Measured from aft (Transom) ?

 

Normally you have 2 l.w.l., one for the fully loaded condition and one for the half load. For this reason I calculate my l.c.g. taking as starting and reference point the ord.#0. The differences are very small and if the transom angle is o deg. there is no difference at all.

 

See this year's SNAME annual meeting. Some of the papers are on line.

 

Ranchi Otto - can you give further details on where you derived this from..."Hatch"....

Thanks

 

I posted a question regarding LCG here

http://www.boatdesign.net/forums/showthread.php?t=18198

Part of my question was as follows -

Any help would be much appreciated