155mm GPF Gun

Coast Artillery Corps Weapons

155mm G.P.F. Gun

The 155mm Filloux Gun

The Yanks made this gun famous. The French, who invented it, did not think it at all an exception. The Americans were very enthusiastic about it and accomplished results the French thought impossible with such a gun.

The G.P.F., as it is known is a rifle of 155-millimeter bore, or about six inches. The length of the barrel is 19 feet, 5 inches. The length of the entire piece in traveling position is 28 feet, 6 inches. The piece can be fired with a full charge from 0 to 35 degrees elevation, and possesses a horizontal field of fire of 60 degrees. The maximum range reached with the steel shell is about 16 kilometers or about 10 miles. The shell travels at a speed of 2,700 feet per second; an unbelievable velocity for a shell of this calibre, weighing 96 pounds, to pass through the air. The gun cradled which constitutes the oscillating mass, rests on the top carriage by means of the cradle trunnions. The top carriage is supported by the chassis, on which it turns when the gun is laid for direction. The chassis, on which is mounted the barrel, forms a platform, carried by the gun axle and the two trials. The gun is provided with rubber-tired wheels, constructed to receive Caterpillar Bands. When in firing position trails are opened and anchored in the ground by means of spades attached to the trails. The weight of the chassis rests directly on the gun axle at a single point only, through the agency of the pivot in; this arrangement permits the axle to follow the irregularities of the ground. When in traveling position the trails are closed, locked together, and secured on the limber. The limber is merely a carriage on which rests the rear ends of the trails and is supplied with a rubber tired wheels, and is steered in a similar manner to an automobile. The limber wheels are the same as those of the gun proper. They are intended to receive the Caterpillar Bands if the nature of the ground makes this necessary. The gun wheels are provided with brake drums. The total weight of the rifle in road position, without trail spades or Caterpillar Bands, is 25,740 lbs., or a trifle more than 12 tons.

The gun is classed as Heavy Artillery, but being perfectly balanced and mounted on rubber tired wheels, it can be moved about with considerable rapidity. It is pulled by high-powered Renault trucks or Holt caterpillar tractors.

A gun in road position could make 15 mi. an hour on a level road and this was one of the factors that contributed to its great successes. In beauty the gun has no comparison. A long, graceful barrel; rigidly constructed and attractively designed trails; neat and strong iron wheels with rubber tires; has a very low road clearance and impresses one as a powerful, destructive Greyhound.

Capacity of the Powder Chamber 1329 cu. in.
Type of Powder Bag
Powder Charge, Propelling 26 lbs.
Powder Charge, Bursting (shell) 9.5 lbs
Travel of the projectile in the barrel 185 inches
Max pressure (lbs to Sq. in.) 31,500
Muzzle velocity, feet per second 2,322
Weight of shell 95 lbs.
Max elevation 35 degrees
Loading elevation any
Max Range 18,300 yds
Number of grooves in the barrel 48
Angle of the grooves 6 degrees
Ship tonnage required for gun with limber 40

If you have research comments or additional information on this page e-mail them to: Joe Hartwell

This page was last updated on Sat, Jun 16, 2007

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