| 16"/50 caliber Mark 2 Gun | |
|---|---|
 16"/50 Mark 2 gun on display at the Washington Navy Yard. | |
| Type | |
| Place of origin | United States |
| Service history | |
| In service | 1924–47 as coastal defense gun |
| Used by | |
| Wars | World War II |
| Production history | |
| Designed | 1916 |
| Manufacturer |
|
| Produced | 1917–22 |
| No. built | 71 |
| Variants | Marks 2 and 3 Mods 0 and 1 |
| Specifications | |
| Mass | 284,000 pounds (129,000 kg) |
| Length | 68 feet 0 inches (20.73 m) (without breech) |
| Barrel length | 66 feet 8 inches (20.32 m) bore (50 calibers) |
| Shell |
|
| Caliber | 16-inch (410 mm) |
| Recoil | 49-inch (120 cm) |
| Elevation |
|
| Traverse |
|
| Rate of fire | 2 rounds per minute |
| Muzzle velocity |
|
| Effective firing range | 45,100 yd (41,200 m) at 46° elevation on coast defense mount |
The 16"/50 caliber Mark 2 gun and the near-identical Mark 3 were guns originally designed and built for the United States Navy as the main armament for the South Dakota-class battleships and Lexington-class battlecruisers. The successors to the 16"/45 caliber gun Mark I gun, they were at the time among the heaviest guns built for use as naval artillery.[2]
As part of the Washington Naval Treaty of 1922, both of these ship classes were cancelled part way through construction, rendering surplus about 70 examples of the 16-inch/50 which had already been built. Twenty were released to the United States Army, between 1922 and 1924, for use by the Coast Artillery Corps, the rest were kept in storage for future naval use. Only ten of the twenty available guns were deployed (in five two-gun batteries) prior to 1940.[1][2]
When the design of the Iowa-class battleship began in 1938, it was initially assumed these ships would use the surplus guns. However, due to a miscommunication between the two Navy departments involved in the design, the ships required a lighter gun than the Mark 2/Mark 3, resulting, ultimately, in the design of the 267,900 lb (121,500 kg) 16"/50 caliber Mark 7 gun. In January 1941 all but three of the remaining fifty Mark 2 and Mark 3 guns were released to the Army. They were the primary armament of 21 two-gun batteries built in the United States and its territories during World War II.[2][3] However, none of these were fired in battle.