11-inch gun M1877

In the coastal defense role, the M1877 was mounted on a garrison mount which sat on a concrete slab behind a parapet. The mount consisted of a rectangular steel firing platform with a pivot at the front and two wheels at the front and rear to give 120° of traverse. The recoil system for the M1877 consisted of a U shaped gun cradle which held the trunnioned barrel and a slightly inclined firing platform with a hydro-gravity recoil system. When the gun fired the hydraulic buffers under the rear slowed the recoil of the cradle which slid up a set of inclined rails on the firing platform and then returned the gun to position by the combined action of the buffers and gravity. Due to its limited angle of elevation 20°, the M1877 was a low-angle direct fire weapon instead of a high-angle indirect-fire coastal defense mortar like many of its contemporaries.[2]

In the fortress and siege gun roles, the M1877 used the same type of garrison mount as in the coastal defense role. Due to their weight, the guns were not designed to be mobile. After a string of Russian defeats in the first two years of the war, a number of M1877's were captured by the Germans. In 1916 the Germans transferred four M1877's to the Western Front where they were assigned to heavy artillery battalions of the army. Details of their employment are unknown and all are believed to have been withdrawn before 1918. However, since they didn't have very good range and they weren't capable of high angle fire they may have been used in their original coastal defense role instead of in a siege artillery role. In German service the guns had better range due to more efficient smokeless powder and more aerodynamic German projectiles.[2]