| From: | Paul J. Adam Paul@********.demon.co.uk |
|---|---|
| Subject: | Submarines (was RE: Shipping (was Re: the value of education)) |
| Date: | Fri, 16 Jul 1999 17:47:42 +0100 |
Graht <Graht@**********.worldnet.att.net> writes
>Not quite. Small craft (up to and including yachts) have a sharp prow.
So do most warships.
>However, most big ships have a blunted "probe-like" extension below the
>surface, shaped almost exactly like the front end of a sub. Since it's
>under water it looks like the large boat has a sharp prow, but in fact it
>doesn't. I don't know about the physics of it, but large ships don't have
>a sharp prow in general.
Merchant ships are designed to run at one speed and do so for most of
their lives. The bulbous forefoot you describe is used to create a second
bow wave, out of phase with that made by the hull, and so reduce the
wavemaking resistance of the ship. The effect is highly speed-specific.
Warships have to operate over a much greater range of speeds and so do
not use bulbous bows.
--
Paul J. Adam
