Anti-torpedo boat gun of the late 1800s. Some of these were converted to AA guns during World War I. None appear to have survived long enough to serve during World War II.
| Designation | 12-pdr [3"/50 (7.62 cm)] 18cwt QF Mark I |
|---|---|
| Ship Class Used On | Battleships: King Edward VII (last three units), Lord Nelson and Dreadnought classes 1 Cruisers: Minotaur class Monitors: Abercrombie, Lord Clive, Marshal Ney and Erebus classes, plus M15 through M28 |
| Date Of Design | N/A |
| Date In Service | N/A |
| Gun Weight | 0.9 tons (1.0 mt) |
| Gun Length oa | 154.7 in (3.929 m) |
| Bore Length | about 150 in (3.810 m) |
| Rifling Length | N/A |
| Grooves | N/A |
| Lands | N/A |
| Twist | N/A |
| Chamber Volume | N/A |
| Rate Of Fire | 15 rounds per minute |
- ^This gun or a close copy was also used on HMS Agincourt (ex-Rio de Janeiro).
| Type | Separate |
|---|---|
| Weight of Complete Round | N/A |
| Projectile Types and Weights | HE 2crh: 12.5 lbs. (5.67 kg) |
| Bursting Charge | N/A |
| Projectile Length | N/A |
| Propellant Charge | 2.75 lbs. (1.25 kg) MD |
| Muzzle Velocity | 2,600 fps (792 mps) |
| Working Pressure | N/A |
| Approximate Barrel Life | 1,200 rounds |
| Ammunition stowage per gun | Monitors: 300 rounds
Lord Nelson: 230 rounds Dreadnought: 300 rounds Others: N/A |
| Elevation | Distance |
|---|---|
| 20 degrees | 9,300 yards (8,500 m) |
| Designation | Single Pedestal Mounting
Battleships: Africa (14), Britannia (14), Hibernia (14), Lord Nelson (24) 1a, Dreadnought (28) 2a and Agincourt (10) Cruisers: Minotaur (18): PIV Monitors: Generally had 1 or 2 guns |
|---|---|
| Weight | 1.71 tons (1.74 mt) |
| Elevation | -10 / +20 degrees |
| Elevation Rate | Manually operated, only |
| Train | 360 degrees |
| Train Rate | Manually operated, only |
| Gun recoil | N/A |
- ^The Lord Nelson class was reduced to 18 guns during the war with the removed guns used on other warships.
- ^HMS Dreadnought completed with 28 guns but this was increased to 31 by fitting additional guns to the roofs of the centerline turrets.
- Some guns were later converted for HA use. From the Australian War Memorial picture H18888 noted above, these appeared to have used very simple, extemporized mountings.
"British Battleships of World War One" by R.A. Burt
"Big Gun Monitors: The History of the Design, Construction and Operation of the Royal Navy's Monitors" by Ian Buxton
"British Battleships: 1860 - 1950" by Oscar Parkes
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Special help from Rod Butcher
28 December 2008 - Benchmark
04 February 2014 - Added ammunition stowage and number of guns
21 May 2014 - Added ammunition stowage for Lord Nelson class
29 November 2015 - Changed Vickers Photographic Archive links to point at Wayback Archive
22 July 2025 - Converted to HTML 5 format, added mention of HMS Agincourt