Introduced to the Royal Navy in March of 1915 as a large-caliber AA MG. Generally similar to the later 2-pdr Mark VIII including using the same water-cooled barrel, but the automatic mechanism was lighter and less robust. First models used a 25-round fabric belts, the later Mark II*C used a 14-round steel-link belt. Used only in single mountings. Britain produced a total of 795 guns of which 577 were still available in 1939.
The original Mark II design was prone to faults and the later Mark II* was a modified version which improved reliability. Stoppages and jams were still frequent in these models, as the rounds slipped out of their holders and the fabric belts often stretched and tore.
Actual bore length was 39.37 calibers.
Some fifty of these guns were sold to the Italian Navy. They were then manufactured under license by Terni (Italy) until the early 1930s. The Terni version used a 50 round ammunition box.
Russia ordered a number of these guns from Vickers during World War I and by 1916 forty of them were on hand in the Russian Navy (20 each in the Baltic and Black Sea fleets). In 1916 the Russian Navy ordered sixty additional guns from the Obukhov factory with at least twelve of them being delivered by 1917. All of these weapons used 25 round belts.
There was also an earlier Mark I version, but I lack details as to what were the differences between it and the Mark II.
The data that follows is for the British version except where otherwise noted.
|Designation||British: Vickers 2-pdr QF Mark II
Italian: 40 mm/39 Vickers-Terni 1915/1917
Russian: 40 mm/39 Vickers Automatic Model 1914
|Ship Class Used On||Many|
|Date Of Design||about 1914|
|Date In Service||British: 1915
Italian: about 1917
|Gun Weight||British and Italian: 550 lbs. (249 kg) including cooling water
Russian: 504.9 lbs. (229 kg) (probably does not include water)
|Gun Length oa||96.0 in (2.438 m)|
|Bore Length||62.0 in (1.575 m)|
|Rifling Length||54.84 in (1.293 m)|
|Grooves||(12) 0.0141 in deep x 0.322 (0.358 x 8.18 mm)|
|Lands||0.894 in (2.271 mm)|
|Twist||Uniform RH 1 in 30|
|Chamber Volume||9.98 in3 (0.165 dm3)|
|Rate Of Fire||200 rounds per minute cyclical
about 50 - 75 rounds per minute practical
|Weight of Complete Round||HE: 2.95 lbs. (1.34 kg)|
|Projectile Types and Weights
|HE: 2.0 lbs. (0.9 kg)|
|Bursting Charge||0.21 lbs. (0.1 kg)|
Complete round: 11.995 in (30.47 cm)
|Propellant Charge||0.243 lbs. (0.11 kg) HSCT/K 134-055|
|Muzzle Velocity||British: 1,920 fps (585 mps)
Italian: 2,000 fps (610 mps)
Russian: 1,972 fps (601 mps)
|Working Pressure||15.5 tons / in2 (2,440 kg / cm2)|
|Approximate Barrel Life||5,000 rounds|
|Ammunition stowage per gun||
|Empty body||1.45 lbs. (0.66 kg)|
|Driving band||0.875 oz (0.025 kg)|
|Paint||0.125 oz (0.0035 kg)|
|Bursting charge||2.5 oz (0.071 kg)|
|Fuze No 131||5.25 oz (0.15 kg)|
|Total filled||2 lbs. (0.9 kg)|
|Elevation||-5 / +80 degrees|
|Elevation Rate||Manually operated, only|
|Train Rate||Manually operated, only|
- ^Mark XV was a powered mounting similar to the Mark XVI mounting for the the 2-pdr. Mark VIII. Twenty-eight were produced during World War II and the surviving twenty-three were scrapped in early 1944.
- "The Italian Navigatori Class, 1926" article by Elio Andò in "Warship Special 2: Super Destroyers" edited by Antony Preston
- "Big Gun Monitors: The History of the Design, Construction and Operation of the Royal Navy's Monitors" by Ian Buxton
- "Naval Weapons of World War Two" by John Campbell
- "L'artiglieria Italiana nella Grande Guerra" (Italian Artillery of the Great War) by Andrea Curami and Alessandro Massignani
- "British Cruisers of World War Two" by Alan Raven and John Roberts
- "Entsiklopedia Otechestvennoi Artillerii" (Encyclopedia of Fatherland (Russian) Artillery) by A.V. Shirokorad
- "Q.F. High Explosive 2 pdr Mark II N Shell - Forged Steel with Fixing Screw. Design." No. 21,071.c.(1) / A.D.G.S/3/164 dated 24 February 1916
Special help from Vladimir Yakubov, Caspar Vermeulen and Anthony G. Williams