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3-inch M1902 seacoast gun

3-inch gun M1898, M1902, M1903
M1903 3 inch Gun.png
3-inch gun M1903
Type Rapid-fire seacoast gun
Place of origin United States
Service history
In service 1899–1945
Used by United States Army Coast Artillery Corps
Wars World War I and World War II
Production history
Designed
  • M1898: 1898
  • M1902: 1902
  • M1903: 1903
Manufacturer
Variants
  • M1898, M1898M1
  • M1902
  • M1903, M1903MI
Specifications
Weight
  • M1898: gun & breech 1,782 lb (808 kg)
  • M1902: gun & breech 1,950 lb (885 kg)
  • M1903: gun & breech 2,690 lb (1,220 kg)
Length
  • M1898: 155 in (394 cm)
  • M1902: 159 in (404 cm)
  • M1903: 175 in (444 cm)
Barrel length
  • M1898 & M1902: 50 calibers (150 in (381 cm))
  • M1903: 55 calibers (165 in (419 cm))
Crew
  • 15 (wartime),
  • 12 (peacetime),
  • 3 to operate the gun, remainder to handle ammunition

Shell Fixed ammunition, 15 lb (6.8 kg) shell
Caliber 3-inch (76.2 mm)
Action Hand operated
Breech interrupted screw, De Bange type
Recoil hydrospring, 45 inches (114 cm)
Carriage

M1898: masking parapet (retractable)

M1902 & M1903: pedestal
Elevation -5° – +16° (+15° for M1898 and M1902)
Traverse 360° (limited by emplacement in most cases)
Rate of fire 12 rounds/minute (up to 30 rounds/minute maximum)
Muzzle velocity 2,800 ft/s (850 m/s)
Effective firing range

M1902: 10,988 yd (10,047 m)
at 15° elevation

M1903: 11,328 yd (10,358 m)
at 16° elevation
Maximum firing range 12,000 yd (11,000 m) approx.
Feed system Manual
Sights Telescopic

M1898: masking parapet (retractable)

M1902: 10,988 yd (10,047 m)
at 15° elevation

The 3-inch gun M1903 and its predecessors the M1898 and M1902 were rapid fire breech-loading artillery guns with a 360-degree traverse. In some references they are called "15-pounders" due to their projectile weight. They were originally emplaced from 1899 to 1917 and served until shortly after World War II. These 3-inch guns were placed to provide fire to protect underwater mines and nets against minesweepers, and also to protect against motor torpedo boats. In some documentation they are called "mine defense guns". The 3-inch guns were mounted on pedestal mounts (or a retractable "masking parapet" mount for the M1898) that bolted into a concrete emplacement that provided cover and safety for the gun's crew.

The 3-inch mine defense guns were part of a comprehensive plan of new fortifications specified by the Endicott Board of 1885. The new forts included guns up to 12-inch (305 mm) on disappearing carriages, to conceal the fort from observation from the sea. The 3-inch guns were the smallest of these guns, intended to protect remotely controlled minefields against minesweepers. For most of their service they were operated by the United States Army Coast Artillery Corps.

The M1898 was the first of the new 3-inch guns developed. It was manufactured by Driggs-Seabury and was on an M1898 "masking parapet" retractable carriage, conceptually similar to the disappearing carriages of the larger guns. 111 of these weapons were emplaced 1899–1905. The carriage could only be retracted when the gun was at a particular train angle (in most installations 90° off the emplacement axis in either direction), thus it provided no concealment in action. Eventually the retraction feature was disabled, with the modified carriage designated M1898MI. The weapon was in any case small enough that the risk of observation from the sea was minimal. Most or all of the M1898 guns and carriages were removed from service in 1920 due to obsolescence and probably the manufacturer's bankruptcy.


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Wikipedia

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