Re: Electric Drive and COGAD

On Mon, 29 Dec 2008 14:55:51 -0000, "Keith Willshaw"
<keith@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:


<Alexander Lanson> wrote in message
news:v34fl41rqbr46ful6u9l9koa7ukmfff1ni@xxxxxxxxxx
In message <Xns9B72F4132C45EtsalagiNOSPAMasusnet@xxxxxxxxxxx>, Dennis
<tsalagi18NOSPAM@xxxxxxxxxxx> writes
What are the problems with using electric drive on a surface ship?

Most new large civillian ships are fully electric (diesel generators
powering electric motors).

No they arent, most large civilian ships use direct drive low speed
diesel engines.

They are very good for cruising at 22 knots
but can't provide enough power for high speed sprints.


Wrong again. The relatively few ships that have electric drive
tend to be passenger ships and vehicle ferries and one of the advantages
of that electric drive is the ability to use modular engine installations to
boost power when needed. High and medium speed diesels are quite
capable of powering fast ships, see the WW2 Panzerschiffe for an
example.


Weren't all the panzerschiffe rendered useless by one kind of
machinery failure or another? (Graff Spee's by her fuel prep
system being shot away in 1939, so that one's iffy)

There are many ships in the 25 knot class driven by direct drive
diesels, but not too many much faster than that that I'm aware
of.

Peter Skelton
.

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