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"Italian Illuminating Projectile" from Tactical and Technical Trends

The following U.S. army report on the Italian illuminating projectiles was originally published in Tactical and Technical Trends, No. 46, May 1, 1944.

[DISCLAIMER: The following text is taken from the U.S. War Department publication Tactical and Technical Trends. As with all wartime intelligence information, data may be incomplete or inaccurate. No attempt has been made to update or correct the text. Any views or opinions expressed do not necessarily represent those of the website.]


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 or metal.

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.


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