From: fldcmput@kgv1.bems.boeing.com
Subject: Re: Light Tanks in Bosnia
Keywords: Sheridan, 82nd Abn, Light Tanks
Date: Sat, 16 Dec 1995 22:24:11 GMT

In article <DJI4J9.77t@ranger.daytonoh.attgis.com> Jaeger <wjohnson@io.com> writes:

>Some one with 1st person experience could give you a 
>better evaluation...

I served with that unit about 15 years ago, and have kept up with
developments since.

>To the best of my knowledge the M-551 Sheridan Tanks are still in service 
>with the 82nd ABN.... Unit size I believe is a battalion.

That is correct.  Depending on the exact TO&E, they will have
either 54 or 58 Sheridans.


>They mount a 155 smooth bore gun that can fire either 
>missles or standard tank rounds.

The cannon is a 152mm rifled tube.  The "standard" rounds
are 152mm HEAT rounds.  The recoil from firing one of
those things is enough to lift two roadwheels clear
of the ground (because the tank is so light).  The driver
gets quite a ride.

The missile does not engage the riflings, and is not
spun.  The gun tube has a keyway slot which the missile
engages to keep it from spinning.  The missile has an
effective range of about 3000 meters and carries a single
stage shaped charge.

>The design is very old it is the only US tank to use 
>the Christie suspension system.

The design dates back to Vietnam, mid '60s.  There have
been a number of updates since, including significant
improvements in the automotives, installation of laser
range finders and thermal sights.  Reliability was
(in my subjective experience) in line with other heavilly
used tracked systems of similar complexity.

There is a lot of mis-information about a "Christie"
suspension.  Walter Christie designed a suspension
consisting of large road wheels, no support rollers,
with a specific type of spring-shock absorbing
design.  It is common to refer to any vehicle that
has no return rollers (M113, Sheridan, most pre-T72
Soviet armor, etc) as having a "Christie" suspension.
In reality, all of  these vehicles use torsion bar
suspensions.

>I have heard some not very good reviews about them, 
>armor to light if you air drop them the 
>missle sighting system gets thrown off, and they ride like a hell over 
>rough terrain.

The standard way to air-drop Sheridans is by Low
Altitude Parachute Extraction System (LAPES) whereby
a set of drag chutes pulls the vehicle out of a low
flying C-130 (low meaning about 6-10 feet) and the
vehicle (lashed to a pallet) drops to the ground at
130 knots horizontal speed and skids to a stop.  We did
this frequently at Ft Bragg, and usually had little or no
problems with the vehicles.  The missile fire control
alignment procedure is routine maintenance and takes
a few minutes.. and any fire control system should
be checked after that kind of shock.  As far as the
ride was concerned, I didn't find them any better or
worse than other vehicles of that era.  (The M1 and
other new generation vehicles are excluded from that
assessment.)  If you want a rough ride, take an M60A3
across a plowed field. :(

Hope this helps.