The U.S. Model 1918M1 155mm Gun, more commonly known as the "G.P.F.", was a French heavy artillery piece manufactured in the U.S. for use by the U.S. Army during World War I. Due to the gun's mobility and hitting power, it was used during the 1920's and 1930's as a coast defense weapon. By 1944, the M1918M1 gun and the M1918AA carriage with its solid rubber tires were no longer in front line service and had been relegated to a support role. During World War II, Battery F of the 50th Coast Artillery Regiment manned two M1918M1 GPF guns (Nos. 176 and 802) at Fort Morgan, initially in field emplacements and later on "Panama" mounts on top of the fort.
Weight of Gun and Carriage: 19,860 pounds
Weight of Projectile: 95 pounds
Muzzle Velocity: 2,360 feet per second
Range: 20,000 yards
Rate of Fire: 4 rounds per minute