moms
III.
POSITIONING OF WEAPONS BARGE FOR SURFACE SHOT OVER DEEP WATER W. Thaler, et al
The plans for placing and mooring the weapons berge as presented
by Thaler, Waleh and Fitzpatrick are illustrated in Figs. 1 and 2.
Further description of the proposal and comments made by the group are
noted below.
Because of the information desired on underwater pressures, the
first question considered in working out this proposal was how far
from the reef the barge should be positioned in order to get away from
reflections of the pressure wave off the reef. That is, they wanted
to make sure the arrival time from the bottom refracted ray would not.
distort theapparent shookwave,
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worries do not enterforthefirsttwo stations, but for the third it
turns out that (assuaing a clean pressure shook wave fran the water),
if the targe is positioned in 4000-ftedeep water, the bottom refracted
wave should arrive 16 nsec after the arrival of the initial shook pulse.
On this basis they locked at the submarine geology of the southwestern
portion of Bikini, again using Crossroads data for the profile of the
reef, and the point at which the water is 4000 ft deep is 1-1/2 - 1-3/4
miles offshores
For the stringing out of the shore cable, a calculation was made
to see how many flotation buoys would be needed to support it over the
surface. A 40-float array was firet considered, with a span of 200 ft
between floats, considering the tension required to maintain 20eft sag
in the catenary. As noted in Fig. 1, 1-1/4" diameter wire rope will be
used, with a breaking strength of 108,000 lbs. They then decided a
lesser mumber of floats would be adequate, went to 20.
The total
tension required to maintain this catenary all along is 8315 lbs.
The Wigwam people have considered mooring problems and they find
that for a 15-knot average wind speed the force exerted on a bare barge
4s 800 lbs. Thaler did not know how large the weapon cab will be so
had not caloulated the a dditional force but stated it is a simple
ge
we ewe ne ee em ere en
In the mooring considerations, the barge was assumed to be equivalent to a 500=-ton YC. Ogle stated this is correct on the assumption
that we do not have to worry about getting it anchored and then having
appreciable weather. The subject calculationa have safety factors of
& to 7 and Thaler felt they could take care of a 1000-ton barge without
apy strain, should it be that large..