BL 15-inch howitzer

• Name — BL 15-inch howitzer Mk I • Origin — United Kingdom • Type — Heavy siege howitzer • Is Artillery — yes • Is Uk — yes • Service — 1915–1918 • Used By — British Empire • Wars — World War I • Designer — Coventry Ordnance Works • Design Date — 1914 • Manufacturer — Coventry Ordnance Works • Number — 12 • Variants — Mk I • Weight — 94 tons • Cartridge — HE 1450 lb • Caliber — 15 in • Velocity — 1117 ft/s • Max Range — 10800 yd • Breech — Welin interrupted screw • Recoil — Hydro-spring 31 inch constant • Carriage — siege carriage

The weapon was operated by Royal Marine Artillery detachments of the Naval Brigade, with one gun per battery. One gun was sent to Gallipoli but not used there. They were later transferred to the British Army. It was used at the Battle of the Somme in September 1916 and at the Battle of Passchendaele, also known as the Third Battle of Ypres, in October 1917. It operated successfully where it was needed to destroy deep fortifications on the Western Front, but was limited by its relatively short range compared to other modern siege howitzers. The size and weight made it difficult to move and emplace. No further development occurred after the first batch of twelve, and instead Britain continued to develop and produce the 12-inch howitzer and 12-inch railway howitzer.

• Illustration — Rolling shell along rails, Englebelmer Wood, Battle of the Somme, September 1916 • Illustration — German soldier posing with unexploded shell • Illustration — Shell at Royal Artillery Museum, Woolwich, London • Illustration — "Granny" in action during the Third Battle of Ypres, 4 October 1917 • Illustration — Howitzer inspected by a British delegation in 1916 • Illustration — A 15-inch Howitzer being set up

• Škoda 380 mm Model 1916 howitzer Austro-Hungarian equivalent

The following is established of the heading itself. Classified as a BL 15 inch gun or siege artillery. Associated with United Kingdom of Great Britain and Ireland.