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From: swilliam@dtoa1.dt.navy.mil (Williams)
Newsgroups: sci.military
Subject: Re: Disposition of American Battleships
Message-ID: <1990Oct23.190910.7532@cbnews.att.com>
Date: 23 Oct 90 19:09:10 GMT
References: <1990Oct5.034136.546@cbnews.att.com> <1990Oct18.020858.5946@cbnews.att.com>
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From: swilliam@dtoa1.dt.navy.mil (Williams)

In article <1990Oct18.020858.5946@cbnews.att.com> someone writes:
>From: texbell!letni!digi!digi.lonestar.org!user1 ("USER1")
>
>What did we do, put atomic devices on old ships and set them off?
>If so why?  I know it was testing, but how about some detail.

The primary reason for these atomic tests was to see the effects of
nuclear weapons on naval ships.  By seeing the results, the Navy could
design future ships to better withstand the effects of nuclear explosions.

The following information is from "The Effects of Nuclear Weapons,"
by the United States Department of Defense and United States Deparment
of Energy, 1977.

Damage to ships from an air or surface burst is due primarily to the
air blast, since little pressure is transmitted through the water.
At closer ranges, air blast can cause hull rutpure resulting in flooding
and sinking.  Such rupture appears likely to begin near the waterline
on the side facing the burst.  Since the main hull generally is stronger
than the superstructure, structures and equipment exposed above the
waterline may be damaged at ranges well beyond that at which hull rupture
might occur.  Masts, spars, radar antennas, stacks, electric equipment,
and other light objects are especially sensitive to air blast.  Air
blast may also roll and possibly capsize the ship.  Blast pressure penetrating
through openings of ventilation systems and stack-uptake systems can
cause damage to interior equipment and compartments, and also to boilers.

This book did not give much information about the ABLE test, but it
did give some about the Bikini BAKER test.

The aircraft carrier SARATOGA was anchored in Bikini lagoon almost broadside
on to the explosion with its stern 400 years from surface zero.  The
"island" structure was not affected by the air blast, but later the
central part of the structure was observed to be folded down on the
deck of the carrier.  Shortly after rising on the first wave crest,
when the stern was over 43 feet above its previous position, the SARATOGA
fell into the succeeding trough.  It appears probable that the vessel
was then struck by the second wave crest which caused the damage to
the island structure.

Maximum Heights (Crest to Trough) and Arrival Times of Water Waves at
Bikini BAKKER Test:

Distance (yards)      300   660  1,330  2,000  2,700  3,300  4,000
Wave height (feet)    94     47     24     16     13     11      9
Time (seconds)        11     23     48     74    101    127    154


Some 70 ships of various types were anchored around the point of burst
in the shallow, underwater BAKER test.  The BAKER test involved a
20-kiloton explosion.