0000.tank9ItalianWW1

This pic was among others showing tanks. I'm not sure if it's SP.

The image is of a 305/17 gun in travelling position showing its castering rear wheels.

Obice da 305/17 was an Italian howitzer (sometimes classified as mortar) used during World War I. Produced by the Armstrong works in Italy between 1914 and 1917, approximately 30-44 were built. Originally the Obice da 305/17 Modello 15 was a stationary coastal defence gun but was later adapted to a mobile siege artillery role. A number also served during World War II.

Obice da 305/17 G Modello 1917 - The Modello 1917 was also a mobile version designed to disassembled and used in a siege artillery role. A gun battery consisted of two howitzers with 8 wagons, 2 machine guns for defense, a utility wagon, and 5 artillery tractors. The wagons could be towed at 6–8 km/h (4–5 mph) and set up time remained 24 hours.
Obice da 305/17 D.S. - These guns were mounted on the same "De Stefano" carriage for land use and the resulting guns were classified by their size in millimeters 305, their length in calibers 17 and lastly by their carriage type DS which stood for De Stefano. The De Stefano carriage was a clever, but strange looking monstrosity which looked something like a child's 4-wheeled toy-horse when the gun barrel was elevated. The carriage was a large 4-wheeled box-trail design with two non-steerable wheels on the front and two castering wheels at the rear. The wheels were fitted with detachable grousers designed by major Crispino Bonagente for traction on soft ground and were towed in one piece by a Pavesi-Tolotti artillery tractor. When not on the move the grousers were removed and the steel wheels rode on an inclined set of steel rails when in firing position. The steel rails were mounted on a firing platform made of wooden beams which allowed the gun 360°of traverse. When the gun fired recoil which was not absorbed by the recoil mechanism was transmitted to the wheels and the carriage rolled up the inclined rails and then rolled back into firing position. The box trail carriage was tall and wide enough that the breech of the gun was accessible at high angles of elevation without a pit being dug and the gun crew had a bucket and hoist for ammunition handling