USSR naval mines were exposed to the underwater effects of Shot 4: Mk 6-0, Mk 10-9,
Mk 18-0, Mk 25-0, Mk 36-2, Mk 36-3, Mk 39~0, and USSR R-1A.
The statistical validity of the results may be questionable, since only 121 mines of
all typee were expcsed. These results indicated a 95-percent probability that a surfacedetonated 7.0-Mt weapon will neutralize 70 to 93 percent of all Mk 18-0, Mk 25-0,
Mk 36~2, ifk 36-3, and USSR R-1A mines within a radius of 4,500 feet from site zero,
if the mines are in water approximately 180 feet deep. With identical conditions of yield,
height-of-burst, and water depth, results also indicated a 95-perceni probability that
72 to 96 percent of al! Mk 6-0 and Mk 10-9 mines within a radius of 7 000 feet will be
neutralized. For Mk 39-0 mines laid in 180 feet of water, an approx:mate range of
2,800 fect was established as the maximum distance from 2 7.0-Mt surface detonation
at which lethal damage will occur.
Table 4.2 presents 4 summary of the blast effects
of Shot 4 on the minefieid.
The radii of destruction obtained with the 7.0-Mt yield of Shot 4 are impressive: however, for a 20-kt weapon, assuming that cube-root scaling is valid to a first approx:mation, these radii would be only one seventh as large. The limited clearance ranges so
obtained indicate that use of surface-detonated nuclear weapons for navai-minefield
clearance is not feasible.
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