14-inch M1920 railway gun

The 14-inch M1920 railway gun was the last large caliber railway gun to be deployed by the U.S. Army. It was an upgrade of the Navy 14"/50 caliber railway gun. This was meant to build a better railway gun, from past mistakes.

14-inch M1920 railway gun
Class Vehicle
Type Towed Artillery
Manufacturer Watervliet Arsenal
Origin United States of America
Country Name Origin Year
United States of America 1925
Country Name Operational Year Retirement Year
United States of America 1925 1946 View
ManufacturerName Production From Production To Quantity
Watervliet Arsenal 1925 4 View

After the close of World War I, the US Army wanted to incorporate the lessons learned from other railway gun mounts and fulfill coastal artillery requirements for hitting a moving target. An effort to design a more universal mount for the Navy's Mk. IV 14"/50 caliber gun was undertaken.

The primary difference from the earlier Navy versions lies in the M1920 carriage, which could be raised and lowered. Prepositioned fixed mounts were installed at the forts, and the gun's rail trucks could be taken out from under the frame. After the removal of the rail trucks, the gun was lowered and bolted onto a pivot point for 360 degree movement. The M1920 carriage made the gun much more flexible. It allowed for the standard practice of using a curved piece of rail to traverse the gun, and it enabled the gun to be used in a fixed position.

Two guns were deployed to Fort MacArthur. The remaining two guns were deployed to Fort Grant and Fort Randolph in the Panama Canal Zone. The two guns deployed to the Panama Canal Zone could be moved to either coast on the Panama Canal Railway.

Type Railway gun
Place of origin United States
Service history
In service 1925 to 1946
Used by  USA
Wars World War II
Production history
Designed 1920
Manufacturer Watervliet Arsenal
Produced 1925
Number built 4
Weight Tube and recoil band- 230,000 Lbs
Length (18.1 m) 59 feet 6 inches
Shell separate loading, HE, and AP
Caliber 14-inch (355.6 mm)
Breech Interrupted thread, (step-cut)
Recoil hydropneumatic
Carriage railway truck, 14 axles
Elevation 50° fixed, 19° on track
Traverse 7° on track, 360° fixed
Rate of fire 1 rpm
Muzzle velocity 2,650 feet per second (808 m/s)
Effective firing range 22,092 m (48,220 yd)
Feed system hand

End notes