A German document gives details regarding a series of experiments designed to
test the use of what is believed to be irritant smoke at close quarters
against tanks. It should be remembered that an irritant smoke is a
harassing, rather than a lethal, agent. When inhaled, irritant smoke agents
cause sneezing, intense irritation of the nose, headache, nervous
depression, and nausea.
a. First Experiment
The tank was stationary, with hatches closed and engine running. One
smoke hand grenade was set off in the immediate neighborhood of the tank.
A high concentration of smoke was built up in the tank, both by
suction of the engine fans and by penetration through leaks in the forward
entrance hatch, the mantlet of the hull machine gun, the turret ring, and the
turret ventilators. Opening the hatches was not sufficient to ventilate the tank.
Under the conditions set forth above, the crew would be forced to
evacuate the tank after a short period. The driver and hull machine-gunner* would
have suffered most from the effects of the smoke.
b. Second Experiment
As in the first experiment, but with the engine not running.
Similar to those of the first experiment.
Evacuation would have become necessary only after several minutes, and then
probably only for the driver.**
c. Third Experiment
Tank moving; hatches closed. Smoke grenades were thrown at the tank but
did not lodge on it.
There was little reduction in the fighting capacity of the crew, who were
affected more by limitation of vision than by actual penetration of the
smoke into the tank.
d. Fourth Experiment
Tank moving, hatches closed. Two smoke hand grenades, one tied to each end
of a 6 1/2-foot cable, were thrown across the barrel of the
Evacuation of the tank was inevitable within 30 seconds. All possibilities of
observation were eliminated.
If the crew show sufficient presence of mind to put on their gas-masks and rotate
the turret through 180° it is possible to avoid the effects sufficiently to
enable the tank to be brought to safety. In any case, however, the fighting
capacity of the crew would be greatly diminished.
Comment: There is insufficient detail to identify the type of tank upon
which these trials were carried out, but the experiments do show, as the
document points out, that smoke can become an important weapon in combatting
The type of grenade used is not indicated. Much of the effect produced within
the tank is described as being physiological (choking, and vomiting which
is characteristic of irritant smokes) and therefore also depends on the speed
with which the crews adjust their gas-masks.
The German document states that this method of engaging tanks will be
practiced, and preparations made for its use in battle.
* Probably because they are nearer the ground, where the concentration of the smoke cloud is greatest.
** Here, the suction of the engine fan is lacking, and the vision ports of the
driver would provide the principal leakage points.