QF 15-pounder Mark I gun

• Name — Ordnance QF 15-pounder Mk I • Origin — German Empire • Type — Light field gun • Is Artillery — yes • Is Ranged — yes • Is Explosive — yes • Is Uk — yes • Service — 1901–1916 • Used By — United Kingdom • Wars — World War I • Designer — Heinrich Ehrhardt • Manufacturer — Rheinische Metallwaren und Maschinenfabrik • Number — 108 • Weight — Barrel & breech 737 lb; Total 2272 lb • Part Length — Bore 7 ft; Total 7 ft • Crew — 10 • Cartridge — 76.2 x 169mm.R Separate loading QF. Shrapnel, 14 lb • Caliber — 3 in • Rate — 20 rds/min • Velocity — 1674 ft/s • Max Range — 7000 yd? (percussion fuze) 6600 yd (time fuze) • Breech — single motion, tapered block with interrupted collars • Recoil — Hydro-spring, constant, 48 in • Carriage — wheeled, pole trail • Elevation — -5° – 16° • Traverse — 3° L & R

The gun's original design and supply to Britain included no shield, all-steel wheels, axle-tree seats, and a sprung telescoping trail to help with recoil control. The British found the trail unsatisfactory in service, so they permanently pinned it in the closed position. The British also immediately replaced the original all-steel wheels with standard British wooden spoked wheels. It replaced the obsolete BL 12-pounder 6 cwt gun in Royal Horse Artillery service until the QF 13-pounder became available from 1904. When the Territorial Force was formed in 1908, the guns were assigned to its cavalry units, known as Yeomanry. The axle-tree seats were removed as unnecessary because the gunners rode horses, and gun shields were added. The modified carriage was designated Mk I+. This gun is the "15-pounder" to which writers are referring in World War I if they are referring to Royal Horse Artillery (RHA) batteries of the Territorial Force, or Yeomanry. The other "15-pounder", the BLC 15-pounder, was an unrelated gun used by Royal Field Artillery (RFA) batteries of the Territorial Force, although it was also issued to some second line RHA batteries raised in 1914.

• Illustration — A QF 15-pounder of B Battery, Honourable Artillery Company, at Sheik Othman, Aden. The gun was used by Royal Horse Artillery batteries of Territorial Force cavalry (Yeomanry) formations early in World War I, most notably in the campaign in Egypt against the Senussi by 1/A Battery, Honourable Artillery Company and the 1/1st Nottinghamshire Royal Horse Artillery. B Battery, Honourable Artillery Company and Berkshire RHA were in action with these guns in the recapture of Sheikh Othman from the Turks on 20 July 1915, part of the Aden campaign. From 1916, the QF 15-pounder was replaced by the modern 13-pounders and 18-pounders.

54,000 complete rounds (i.e. shell, fuze, cartridge) of German design and manufacture were originally supplied with the guns. These were replaced by British manufactures when used up. The following diagrams show British-made ammunition available in World War I. • — — — — • Mk III Cartridge — Mk VI Shrapnel shell (1 inch G.S. fuze) — No. 65A Fuze (1 inch G.S. gauge) — Mk V Case shot — Mk I high-explosive shell with No. 101 fuze.