Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!att!cbnews!cbnews!military
From: ron@hpfcso.fc.hp.com (Ron Miller)
Newsgroups: sci.military
Subject: Re: re: Electric warship propulsion
Message-ID: <1991Jan7.051427.8642@cbnews.att.com>
Date: 7 Jan 91 05:14:27 GMT
References: <1990Dec17.051438.29694@cbnews.att.com>
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From: ron@hpfcso.fc.hp.com (Ron Miller)

> 
> From: sun!portal!cup.portal.com!Eric_S_Klien
> The nuke subs have no electric batteries and we have no diesel subs.
                ^^^^^^^^^^^^^^^^^^^^^^^^^^ 
>                                                           Eric Klien

This is flat wrong if you are referring to US submarines. ("we" who?)

Nuke boats DO have a very large lead-acid battery. Picture about 
148 cells  1'x1'x6' in series. It is essentially the same as
one half of a WWII diesel boats battery. (It is primarily an emergency/auxiliary
power source to be used for reactor startup or to ride out delays 
while getting a diesel generator online.)


It is correct to say, however, that MAIN propulsion is not via the
battery. However, that does not exclude other auxiliary forms of 
propulsion. 


I am not certain if there are any diesel boats left in commission. Rumors
in the early '80's were that there were a few used for SEAL training.


If you still doubt the battery, I have some "battery well T shirts"
left I can show you-- big acid holes :-))


In general though, electric drive still requires a turbine generator to
produce electricity on a nuke boat. One could suppose that electric
drive might be more "efficient" but it might not be as light or as
reliable as reduction gears from the steam turbine. Indeed, if one is
operating a nuclear power plant, it is hard to be as quiet as a
diesel boat on the battery unless the reactor is totally shutdown,
cooled down, depressurized and one is DIW (dead in the water) that is. 

Ron Miller
ex-Lt USN USS CINCINNATTI SSN-693
(former electrical officer, DCA, EMO, QA officer, Reactor Controls officer etc)