Balloon Bomb - Smithsonian Institution Libraries

The threat of an unheralded explosion with attendant
death and destruction could panic the nation. There was
no way of knowing the possible extent or duration of
balloon launchings. In the dry season, widespread
scattering of incendiary bombs could literally burn out
the vast forests of the Pacific Coast. This was Japan's
intended purpose along with the associated psychological
effect upon the American people. Then, there
was the possibility of using balloons to spread germ
warfare—a far greater menace. 1 The threat to the nation
was more frightening than the military or other government
agencies dared reveal to the public, and so the
situation was played down as much as possible.
For Hie Japanese, this was not a simple air operation.
It took two years of testing and preparation before the
first bomb-carrying balloon was launched from Japan.
But mey drew upon a technology that dated back much
further.
Early Balloon
Programs
At the siege of Venice when no position could be
found for siege guns, it was decided to use balloons for
bombardments. This was during the Italian War of
Independence, 1848-1849, when Austrian Lieutenant
Uchatius undertook the technical development of such
a means of attack. Hot air balloons of thin paper were
used. These balloons could carry bombs weighing thirtythree
pounds for a half hour, and were dropped by
means of a time fuse. The point of departure of the
balloons was determined by the direction of the wind.
No great material damage was done to the enemy,
though one of the charges burst in St. Mark's Square. An
unexpected shift of the wind drove some of the
balloons back to the besiegers and their use was
abandoned.
The Japanese idea of a balloon bomb originated in
1933, when Lieutenant General Reikichi Tada, of the
Japanese Military Scientific Laboratory, was assigned to
the head the "Proposed Airborne Carrier Research and
Development Program" which was to investigate and
develop new war weapons. Several revolutionary
weapons were already under consideration. The "I-Go-
Weapon" was a small wire-controlled, manless tank
which could attack enemy pillboxes and wire entanglements.
The "Ro-Go-Weapon" was a project to develop a
rocket propellant. Still another was a "death-ray"
weapon which could kill enemy soldiers at close range
with a charge of electricity.
Though possible, the Japanese did not consider this aspect.
Figure 3. Japanese paper bombing balloon (A 37180C).
Of all the items under consideration in this series, the
"Fu-Go-Weapon" seemed to offer the most promise. The
idea was based on small, four-meter-diameter (13.1 feet),
constant-altitude balloons capable of carrying explosives.
The wind was to carry the balloons approximately
seventy miles to enemy positions, where the bomb load
would be released by a time fuse. It was hoped that the
results would approximate in range and accuracy those
of the heavy guns used by the Germans against Paris in
World War I. This project appears to have been stopped
in 1935 and never completed.