17 cm mittlerer Minenwerfer

• Name — 17 cm mittlerer Minenwerfer • Origin — German Empire • Type — Medium trench mortar • Is Artillery — yes • Is Uk — ff • Service — 1913–1918 • Used By — *German Empire • Latvia • Wars — World War I • Designer — Rheinmetall • Manufacturer — Rheinmetall • Production Date — 1913–1918 • Number — approx. 2361 • Variants — 17 cm mMW n/A • Weight — 483 kg (1,065 lbs) • Part Length — a/A: 64.6 cm L/3.8 n/A: 76.5 cm L/4.5 • Caliber — 170 mm (6.69 in) • Rate — 20 rpm • Velocity — 200 m/s (656 ft/s) • Range — 300 m (325 yards) • Max Range — 1600 m • Sights — panoramic • Recoil — hydro-spring • Carriage — box trail • Elevation — +45° to 90° • Traverse — 25°

The weapon was developed for use by engineer troops after the Siege of Port Arthur during the Russo-Japanese War of 1905, designed to combat heavier mortars by flinging a lighter shell further in defense of a fortress. It was a muzzle-loading, rifled mortar that had a standard hydro-spring recoil system. It fired 50 kilogram (110 lb) HE shells, which contained far more explosive filler than ordinary artillery shells of the same caliber. The low muzzle velocity allowed for thinner shell walls, hence more space for filler. Furthermore, the low velocity allowed for the use of explosives like ammonium nitrate-carbon that were less shock-resistant than TNT, which was in short supply. This caused a large number of premature detonations that made crewing the Minenwerfer riskier than normal artillery pieces. It was also capable of firing 40 kg gas shells. A new version of the weapon, with a longer barrel, was put into production at some point during the war. It was called the 17 cm mMW n/A (neuer Art) or 'new pattern', while the older model was termed the a/A (alter Art) or 'old pattern'. The a/A models were also modified into the 16a & 16b, with the 16a having a barrel extension screwed onto the old barrel, and the b being created by replacing the barrel of the old model with a rifled barrel blank which was 4cm shorter than the new model barrels. In action the mMW was emplaced in a pit, after its wheels were removed, not less than 1.5 meters deep to protect it and its crew. It could be towed short distances by four men or carried by 17. Despite its extremely short range, the mMW proved to be very effective at destroying bunkers and other field fortifications. Consequently, its numbers went from 116 in service when the war broke out to some 2,361 in 1918. Two pieces of 17 cm mMW was also used by SS Heimwehr Danzig troops during the invasion of Poland.

• The Central Museum of The Royal Regiment of Canadian Artillery, Shilo, Manitoba • At the Australian War Memorial, Canberra • Also in Auburn, Massachusetts, an early short barrel model survives at the American Legion Hall • a/A (1917 Rh.MF. Nr.4490) at the Queensland Museum, Brisbane • n/A (1917 Rh.MF. Nr.5988) at the Perth Zoo (entrance), West Australia • n/A (1917 ZWC. Nr.4986) at the War Memorial Garden, Berry, NSW • n/A (1917 Sächsische Maschinen Fabrik Nr 5184) at the Campbeltown Heritage Centre, Scotland • 4980 outside the District Council Service Center, Roxburgh, Otago New Zealand. • Wilbur Avenue, Cranston, Rhode Island • Memorial Hall, Monson, Massachusetts • Falls Park, Pendleton, Indiana USA • Stavely Centennial Park in Stavely, Alberta has a short-barrelled version (serial number 1972) of the mortar on display along with a Spandau machine gun. • The Vytautas the Great War Museum Home • Royal Canadian Legion Branch #15 Harbour Grace • Monuments aux Morts, Saint-Vran, Côtes d'Armor, France • National Museum of the Marine Corps, Quantico, Virginia (2) • Royal Canadian Legion Branch #138 Sydney, Nova Scotia

• Illustration — An early short barreled version on its carriage • Illustration — The a/A model in transport mode, with wheels attached • Illustration — The n/A model (with long barrel), at the Australian War Memorial, Canberra • Illustration — 1917 a/A mMW Nr.5753 at the Queensland Museum, Brisbane • Illustration — The 1917 n/A model Minenwerfer in the grounds of Campbeltown Heritage Centre, Scotland • Illustration — A diagram of a 17 cm chemical shell • Illustration — A diagram of a 17 cm incendiary shell • Illustration — A 17 cm Minenwerfer being assembled