Path: utzoo!utgpu!watserv1!watmath!att!cbnews!military
From: terryr@ogicse.ogi.edu (Terry Rooker)
Newsgroups: sci.military
Subject: Re: RoRo's and Invasion Support
Message-ID: <1990Aug12.214648.3115@cbnews.att.com>
Date: 12 Aug 90 21:46:48 GMT
References: <1990Aug8.030526.26015@cbnews.att.com>
Sender: military@cbnews.att.com (William B. Thacker)
Organization: Oregon Graduate Institute (formerly OGC), Beaverton, OR
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Approved: military@att.att.com



From: terryr@ogicse.ogi.edu (Terry Rooker)
In article <1990Aug8.030526.26015@cbnews.att.com> lanham@aristotle.ils.nwu.edu (Ryan Lanham) writes:
>
>What are current Roll On Roll Off support capabilities of the fleet in the
>unlikely event of moving large numbers of tanks to a port of limited 
>capabilities?  How many RoRo's does the Navy own, how many Abrams can fit
>on one, and how fast do they go?
>
First, it is a matter of moving more than just tanks.  A division has 
numerous other vehicles that are also required, not to mention other
supplies.  Granted the tanks are the heaviest and most problematic.
The Marines use maritime pre-positioning ships to hold the equipment
of a Marine Expeditionary Brigade.  I believe it takes 6 such ships to
hold the equipment for 1 brigade,  In the context of the current
crisis, I believe the MP squadron in Diego Garcia is enroute to the
Persian Gulf.  A MEB is much larger than an army brigade, and includes
organic air assets.  On the other hand, the Marines do not have as
many heavy vehicles as the Army, so 6 ships per brigade is probably a
safe figure.

The Navy has 13 MP ships, all of which are earmarked for the Marines.
After they have off-loaded the first batch, they could always come
back for more.  There are 9 RoRo ships active, of which 8 are
converted SL-7's with a top speed of 33 kts.  Combat Fleets credits
them with holding 183 (!) M-1 tanks.  They are roughly the size of the
MP ships.  In addition there are 13 RoRos in the Ready Reserve, but
they would take 5-30 days to reactivate.  In addition, crews would
have to be found, an increasingly difficult proposition as the
American merchant marine declines.  The problem with most RoRo is that
they need special port facilties to off-load.  That is one of the
biggest objections to using them.  You just can't park them at any
berth and drive the tanks off.  Not to mention the weight of the tanks
exceeding the load limits of the pier or wharf.  Nevertheless, they
can obviously move a lot of equipment quickly.

Finally there are the ultimate RoRos, although not usually considered
as such; the LSTs.  These vessels are designed to drive up to the
beach or causeway and discharge the vehicles directly onto the shore.
They can also carry causeway sections if the beach gradient is too
shallow.  There are 20 of them, and each can carry 20 tanks.  That
isn't many but they have to be beachable, and they are designed to
support the initial assault, and tanks are not much good below the
high-tide line :-)

The final answer to how many tanks can be lifted relies on how many of
these vessels are in service and available.  For a fleet there are
usually 30-50% of the vessels not available immediately.  As a rough
guestimate, using the RoRo's ONLY for the heavy vehicles, break-bulk or
container ships for the lighter vehicles and cargo, and moving the
personnel primarily by plane, there might be enough in-Navy lift for 2
divisions.  That would entail a complete stop to the normal oprations of
these ships which may not be possible.  The Persian Gulf is a small
body of water, and these ships would make tempting targets.  Sinking
just a couple could remove the teeth from an armored division.
Assuming such protection could be arranged, the Navy could probably
lift 1-2 divisions in a pinch.


-- 
Terry Rooker
terryr@cse.ogi.edu