Since it is probable that the German army may be using illuminating
projectiles of the type manufactured in the Italian government arsenal at Capua
prior to the capture of that city by Allied forces, information concerning these
projectiles is presented herewith.
In firing tests of some of the shells which came into the possession of
Allied ordnance units, the burning of flares at approximately 400 yards above the
target gave excellent illumination according to observers who were about 3,500
yards away from the target area.
Tactically the illuminating projectile has certain desirable capabilities, a
few of which are:
(l) Controlled night observation. Selected night targets or areas can be
illuminated for checking before firing concentrations.
(2) During night attacks the shells may be fired to momentarily blind,
confuse, or demoralize the enemy.
(3) The flare may be used as a means for keeping ground troops in the
proper direction to their objective during night attack.
(4) Two or more incendiary containers for starting fires on the ground
could be used with the flares.
The illuminating projectile was made by the Italians in various calibers,
from 75 mm to 149 mm. Externally the shell resembles the U.S. shrapnel shells.
The Italian shell casing is thin-walled. It was designed especially for
maximum carrying capacity. It is closed at the base by a steel plug and at the
forward end by a short, threaded nose. A lead gas-seal for closing off gun flash
gases from the inside of the projectile is fitted between the base plug and casing.
Securing the base plug to the shell are four copper shear pins, set 90 degrees apart
and extending through the shell casing into the base plug.
A copper rotating band is provided near the base of the shell to insure
rotation for stability in flight. A time fuze is screwed into the forward end of the
projectile and setting of this fuze for time of flight is obtained by turning the
movable portion of the fuze head.
Directly underneath the fuze and through the metal nose of the projectile
there is a bored flash hole which extends down to the top center of the black
powder explosion charge. This charge is securely sealed within a hardwood ogive
block. (Note: The 75-mm shell uses an aluminum block instead of a wood block.)
The block, whether of wood or aluminum, is shaped to fit snugly within the
projectile nose over the flare mixture. Three flash channels are bored through the
block to insure ignition of the flare mixture.
This mixture is contained in a metal cup and consists of four layers; first,
compressed fine black powder for ignition; second, a priming layer; third, the
first burning layer; fourth, base burning layer.
A metal parachute connector is bolted to the top of the flare cup This
connector provides for the attachment of the parachute cords, which are either silk
The parachutes are made of either Japanese silk or fine cotton cloth and
vary in diameter from 20 to 48 inches, depending on the caliber of the projectile.
In shell assembly, the parachute and cords are packed in a split cylindrical steel
container in the base of the shell. This container serves primarily the purpose
of transferring shell bursting pressure from flare cup to base plug. To obtain
uniform rupture of the shell base, the base plug is longitudinally split on an angle
in such a manner that the pressure of the black powder bursting charge will be
transmitted equally to all four shear pins.
Firing is accomplished by increasing the gun target range of sight
sufficiently to put the projectile at the desired height above the target. The time
fuze is set at gun target range. When the projectile arrives at a point over the
target, the black powder bursting charge ruptures the shell base, ignites the
flare and forces the parachute and flare out of the base of the shell to illuminate
the target area.
Illumination periods range from 20 seconds to four minutes, depending on
the caliber of the shell. The light is brilliant, and is whitish to yellow. Areas of
from approximately 1,000 to 2,000 yards in diameter may be illuminated.