Newsgroups: sci.military.moderated
From: Terry Ballinger <ballingt@ne.infi.net>
Subject: Re: Tread Life of a MBT
Date: Thu, 10 Apr 1997 16:37:47 GMT

Craig Lambert wrote:

> I'd heard that M1's originally did not have APU's and that the
> batteries would run down after several hours of use of the
> night-sights and radios to the point where the engine might often fail
> to start.  This led the tankers to use their engines when stopped more
> than might be desireable for concealment and fuel consumption.

Mostly true.  Fortunately, the high frequency whine of the turbine does 
not carry as far as a diesel, and if a scout does hear it at night, it's 
almost impossible to discern an accurate direction to it without getting 
VERY close.  Now, the reason I know this is somewhat embarrasing.  I 
stepped away from my tank in Saudi for some personal relief, and got 
lost in the total darkness.  While I waited to hear some noise, my 
wingman started his tank, and I thought it was mine.  I walked almost 
400m, only to find I was at the wrong tank.  I waited almost two minutes 
before I heard them laugh and say, "We see you, come on up!"  They laid 
their gun towards my tank (using thermals), I borrowed a compass and 
walked back to it.  No I'm NOT an officer (even more embarrassing).  
But, only those who have experienced TOTAL darkness will understand. . .


> I found this somewhat incredible, but the guy telling me was an M1
> platoon cmdr in the California NG at the time.  He told me the M1's
> gas turbine does not do 'idle' and uses great amounts of fuel &
> produces a big heat signature when running just for the purpose of
> supplying electrical juice. Has this issue been addressed?

Yes.  There are three approaches to the solution.  Some units (mostly 
training tanks at various schools) have had an APU fashioned from the 
"little joe" on the M88.  It hangs off of the right rear corner of the 
tank.  Lately, there have been some APUs mounted in the left side of the 
turret bustle.  These are known as External APU's or EAPU's.  The EAPUs 
have been issued to various units in the Army and the Marine Corp.  The 
Army is trying to fund an Under Armor APU (UAAPU) that is a smaller gas 
turbine that will fit in the left rear sponson, displacing about 50 
gallons of fuel.  This "integrated" approach is the most desireable, but 
is very costly.

Hope I've helped.
-- 
Terry Ballinger
President, DTech Consulting

"Death flees the bayonet of the brave."  -  Suverov