types of surface vessels would be
in the neighborhood of 1,200 to
1,800 feet, from surface zero, cen-
breakage, would occur for a distance up to four miles.
This means that if the bomb were
ter of damage on the surface, for
detonated under water more than
Some ships would probably be sunk
out to 2,700 feet, but others in this
range would suffer considerable
tural damage on land would not be
burst of a nominal atomic bomb.
structural damage.
Serious loss of efficiency is to be
anticipated within a radius of 3,600
feet from surface zero. Even at
this distance the peak pressure of
the underwater shock wave would
be over 500 pounds per square
inch. Submerged submarines would
probably be lost out to 2,700 feet
from the explosion.
A not inconsiderable amount of
the shock from a shallow underwater explosion is transmitted as
a shock wave in the air. The data
obtained at Bikini indicate that the
one
mile
from shore,
the
struc-
‘serious.
At one mile from surface zero at
Bikini, the maximum height of the
wave formed in the water, from
trough to crest, was about twenty
feet. Even at a distance of two
miles, the wave height reached a
maximum of ten feet. The water
at Bikini was moderately deep, so
that for an explosion in shallow
water the waves at the same
distance would he twice as high.
Such waves breaking over the
shore could do serious harm to port
facilities and warehouses.
The general type of damage en-
suing
from
a
deep
underwater
energy of the air shock for a nominal atomic bomb is roughly equivalent to 4,000 tons of TNT. Such a
shock would, of course, be capable
burst would approximate those following from a shallow one, since
the effects would be from the shock
wave
transmitted
through
the
The data indicate that a shallow
underwater atomic bomb burst
within something like half a mile
from shore would cause serious
damage to harbor facilities and to
warehouses and other structures
near the water. Partial damage
would extend to somewhat over
one mile. Light damage, mainly
cracking of plaster and window
in ships, resulting in immobilization, would extend to 4,500 feet.
Apart from damage caused by
waves, it is believed that, with the
possible exception of piers and
breakwaters, little harm would result to harbor and shore installations as a consequence of a deep
underwater explosion of an atomic
bomb.
of producing extensive destruction.
water. Shock damage to machinery
Damage From an Atomic Bomb
Following is a table of the air-blast damage of an atomic
bomb as charted from the explosion at Hiroshima and Nagasaki:
0 Feet (“Ground Zero,’ Center of Damage)
Air burst of an atomic bomb.
1,000 Feet
Decks of steel plate girder bridge shift laterally.
2,000 Feet
Limit of severe structural damage to earthquake-resistant reinforced concrete buildings.
Reinforced concrete buildings collapse, 10-inch walis,
6-inch floors.
Mass distortion of heavy steel frame buildings.
Loss of roofs and panels.
3,000 Feet
Virtually complete destruction of all buildings, other
than reinforced concrete aseismic design.
4,000 Feet
Reinforced concrete smoke stack with 8-inch walis overturned.
Roof tiles bubbled (melted by heat).
Fighteen-inch brick walls completely destroyed.
5,000 Feet
Twelve-inch brick walls severely cracked.
Steel frame building destroyed
frame).
(mass destruction of
Light concrete buildings collapse.
6,000 Feet
Severe damage to entire area.
Severe structural damage to steel frame building.
Nine-inch brick walls moderately cracked.
Electrical installations and trolley cars destroyed.
Multi-story brick buildings completely destroyed.
7,000 Feet
Structural damage to multi-story brick buildings.
8,000 Feet
Severe damage to homes, heavy damage to window
frames and doors, foliage scorched by radiant heat.
9,000 Feet
Heavy plaster damage.
Moderate damage to area.
10,000 Feet
Blast damage to majority of homes.
Severe fire damage expected.
Flash ignition of dry combustible materials.
11,000 Feet
Flash charring of telegraph poles.
Roof and wall covering on steel frame building damaged.
Partial damage to structures in area.
12,000 Feet
Light damage to window frames and doors, moderate
plaster damage, complete window damage.
8 Miles
Limit of light damage.
23