A Vickers design which, according to "The Big Gun," was quite different from other VSM or EOC weapons of this caliber. However, no details are given as to what were the differences. From an examination of photographs, it would appear that at least one of the differences was in the design of the breech mechanism. At least 24 guns were purchased between 1912 and 1920.
When España was wrecked after running aground in August 1923, her guns were removed and then used in coastal batteries. When Jaimie I was scrapped in 1939, her guns were also then used in coastal batteries. As of 2006, some of these still survive.
| Designation | 30.5 cm/50 (12") VSM Mark H |
|---|---|
| Ship Class Used On | España Class |
| Date Of Design | about 1910 |
| Date In Service | 1913 |
| Gun Weight | 65 tons (66 mt) |
| Gun Length oa | 616.5 in (15.658 m) |
| Bore Length | 569.3 in (14.461 m) |
| Rifling Length | N/A |
| Grooves | 72 |
| Lands | N/A |
| Twist | RH, details not available |
| Chamber Volume | N/A |
| Rate Of Fire | about 1.5 rounds per minute 1 |
- ^
The Rate of Fire figure given above is found in references for British guns of this caliber, but "Warrior to Dreadnought: Warship Development 1860-1905" quotes Jellicoe's 1906 figures for rates of fire for these guns in gunlayers' tests and in battle practice and notes that the latter figures corresponded well to those actually attained by the Japanese at Tsushima:
Gunlayers Test 2 rounds per minute Battle Practice 1 round per minute
| Type | Bag |
|---|---|
| Projectile Types and Weights 1a | APC Mark VI (2crh): 850 lbs. (386 kg) CPC Mark VIIa: 850 lbs. (386 kg) HE Mark IIa: 850 lbs. (386 kg) HE Aerodynamic 2: 867.7 lbs. (393.6 kg) |
| Bursting Charge | APC Mark VI: 25.7 lbs. (11.7 kg) CPC Mark VIIa: 80 lbs. (36.3 kg) HE Mark IIa: 106.5 lbs. (48.3 kg) HE Aerodynamic: 81.3 lbs. (36.9 kg) |
| Projectile Length | APC Mark VI: 39.7 in (100.8 cm) CPC Mark VIIa: 48.4 in (122.9 cm) HE Mark IIa: 48.3 in (122.7 cm) HE Aerodynamic: N/A |
| Propellant Charge | 287 lbs. (130 kg) |
| Muzzle Velocity | 2,933 fps (894 mps) |
| Working Pressure | N/A |
| Approximate Barrel Life | N/A |
| Ammunition stowage per gun | N/A |
- ^The projectile weights and types given above are mainly those for British 12" (30.5 cm) shells of the early World War I period. I am assuming that the same or similar shells would have been provided to Spain, but that no late-war projectiles such as the "Greenboys" would have been supplied.
Note that the breech engraving is repeated both top and bottom. Engraving reads as follows:
| Engraving | Explanation |
|---|---|
| 30.5 c/m Armstrong Vickers Marca.H. | 30.5 cm (12") gun built by Armstrong Vickers as Mark H |
| E.O.C. 1912 No. 16573 | Built at the Elswick Ordnance Company in 1912 Serial Number 16,573 |
| Peso 65700 KG | Gun weight of 65,700 kg (144,842 lbs.) |
| No. DE. 0.17025 2 | Not certain, possibly a Spanish acquisition serial number |
| Cañon de la Derecha | Cannon of the right (the right hand gun in the twin turret) |
- The Vickers Photographic Archive
- See 30.5cm, 6457 and 6476
Data from:
- "Battleships of the World: 1905-1970" by Siegfried Breyer
- "Warrior to Dreadnought: Warship Development 1860-1905" by D.K. Brown
- "The Big Gun: Battleship Main Armament 1860-1945" by Peter Hodges
- "Battleships of World War I" by Peter Hore
- "A Concentrated Effort: Royal Navy Gunnery Exercises at the End of the Great War" article by William Schleihauf in "Warship International" No. 2, 1998
Other:
- ADM 186/169
Special help from Neil Stirling, Javier Villarroya del Real and Caspar Vermeulen
- 21 July 2007
- Benchmark
- 18 February 2012
- Updated to latest template
- 02 December 2015
- Changed Vickers Photographic Archive links to point at Wayback Archive