28 cm SK L/40 Large spanner or key for the Amiens Gun

Large, heavy steel spanner or key to fit a circular object 16 1/2 inches in diameter, the spanner is marked C 100 [as 10092]. Found at Harbonnieres.

This large spanner forms part of the maintenance equipment captured with the 28 cm SK L/40 German Railway Gun ("Amiens Gun") at Harbonnieres on 8 August 1918.

The Germans employed the railway gun, better known as the 'Amiens Gun', to shell the railway marshalling yards at Amiens with the intention to disrupt the flow of men and materials to the front lines. Lieutenant (Observer) Alec Stewart Paterson, No. 3 Squadron, Australian Flying Corps (AFC), while on patrol with Captain (flight commander) J R Duigan on 22 April 1918, is credited with being the first to detect this German railway gun that was shelling Amiens from Harbonnieres. The HE shell fied by this gun weighs approximately 320 kilos.

The gun was captured by 31 Battalion AIF on 8 August 1918 along the Villers-Bretonneux front. After the gun was captured by Australian forces it was briefly displayed in Paris before being shipped to Australia per SS Dongarra in October 1919. When the gun arrived in Australia, it was displayed at Central Railway Station in Sydney, before being moved to a special railway siding in Canberra from 1923 to 1942.

During the Second World War, the gun carriage was used by the Australian Army for munitions and barrel trials for 8 inch naval guns at the artillery proof range in Port Wakefield, South Australia. The gun mounting was operational for proofing 8 inch guns from 1943 to 1947. The gun mounting and railway bogies were scrapped in the early 1960s, the barrel being the only sizeable relic left intact.

The design of this barrel dates back to 1901 when it was originally mounted in the Deutschland and the Braunschweig class pre-dreadnought battleships. During 1914 the gun design was modified for coastal artillery and later formed the basis of a series of 28 cm railway gun artillery pieces.