damage

A reference to the various photographs depicting damage
shows that although most of the buildings within the
effective limits of the blast were totally destroyed or severely
damaged, a large number of chimneys even close to
X were left standing, apparently uninjured by the concussion.
One explanation is that concrete chimneys are approximately
cylindrical in shape and consequently offer
much less wind resistance than flat surfaces such as buildings.
Another explanation is that since the cities were subject
to typhoons the more modern chimneys were probably
designed to withstand winds of high velocity. It is also
probable that most of the recently constructed chimneys
as well as the more modern buildings were constructed to
withstand the acceleration of rather severe earthquakes.
Since the bombs were exploded high in the air, chimneys
relatively close to X were subjected to more of a downward
than a lateral pressure, and consequently the overturning
moment was much less than might have been anticipated.
Although the blast damaged many bridges to some extent,
bridge damage was on the whole slight in comparison
to that suffered by buildings. The damage varied from only
damaged railings to complete destruction of the superstructure.
Some of the bridges were wrecked and the spans were
shoved off their piers and into the river bed below by the
force of the blast. Others, particularly steel plate girder
bridges, were badly buckled by the blast pressure. None of
the failures observed could be attributed to inadequate
design or structural weaknesses.
The roads, and railroad and street railway trackage sustained
practically no primary damage as a result of the explosion.
Most of the damage to railroads occurred from
secondary causes, such as fires and damage to bridges or
other structures. Rolling stock, as well as automobiles, trolleys,
and buses were destroyed and burned up to a considerable
distance from X. Streets were impassable for awhile

because of the debris, but they were not damaged. The
height of the bomb explosion probably explains the absence
of direct damage to railroads and roads.
A large part of the electric supply was interrupted by the
bomb blast chiefly through damage to electric substations
and overhead transmission systems. Both gas works in
Nagasaki were severely damaged by the bomb. These works
would have required 6-7 months to get into operation. In
addition to the damage sustained by the electrical and gas
systems, severe damage to the water supply system was
reported by the Japanese government; the chief damage
was a number of breaks in the large water mains and in
almost all of the distributing pipes in the areas which were
affected by the blast. Nagasaki was still suffering from a
water shortage inside the city six weeks after the atomic
attack.
The Nagasaki Prefectural report describes vividly the effects
of the bomb on the city and its inhabitants:
“Within a radius of 1 kilometer from X, men and animals
died almost instantaneously and outside a radius of 1 kilometer
and within a radius of 2 kilometers from X, some
men and animals died instantly from the great blast and
heat but the great majority were seriously or superficially
injured. Houses and other structures were completely destroyed
while fires broke out everywhere. Trees were uprooted
and withered by the heat.