Austrian troops stand with a captured Obice 305/17 howitzer.

Austrian troops stand with a captured Obice 305/17 howitzer. These 305 mm pieces were fitted into the enormous carriage you see here, which has a very odd shape. They could be fired and transported from within this 3 meter tall carriage.
Obice da 305/17
bice 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 defense gun but was later adapted to a mobile siege artillery role. A number also served during World War II.

In 1908 the Italian coastal artillery analyzed reports from the Russo-Japanese War of the performance of their Armstrong 280 mm (11 in) howitzers that they had supplied to Japan and found them unsatisfactory. They then turned to the companies Armstrong, Krupp, Schneider, St Chamond and Vickers-Terni for proposals for a 305 mm (12 in) howitzer. The Inspector General of Artillery chose the design from Armstrong-Pozzuoli, with modifications to the ammunition, and loading system.

World War I
Although the majority of combatants had heavy field artillery prior to the outbreak of the First World War, none had adequate numbers of heavy guns in service, nor had they foreseen the growing importance of heavy artillery once the Italian Front stagnated and trench warfare set in. Fortresses, armories, coastal fortifications, and museums were scoured for heavy artillery and sent to the front. Suitable field and rail carriages were built for these guns in an effort to give their forces the heavy field artillery needed to overcome trenches and hardened concrete fortifications. Indirect fire, interdiction and counter-battery fire emphasized the importance of long-range heavy artillery. In order to address the Italian Army's lack of long-range heavy artillery 254B, 254/40, 305/17, 305/40, and 305/46 Naval Guns were converted to land use.

The first howitzers entered service with units of the coastal artillery in 1914, with 12 at La Spezia, 4 at La Maddalena and 4 at Messina. In October 1917, 38 pieces were available in the three versions. A number of guns were disassembled and redeployed to the Alpine front to act as siege artillery. After the loss of 9 guns following the Battle of Caporetto, another 18 were produced between 1 July 1918 and 30 June 1919, thus reaching the total of 44 guns, of which 8 were in reserve.

Spanish Civil War
In 1937, 5 pieces were delivered to the Nationalists during the Spanish Civil War.

World War II
In 1939, 10 Modello 16 and 17 Modello 17's were in service. These armed the 540th battery of the 22nd Artillery Group of the Guardia alla Frontiera (G.a.F.), a battery of the XXIX and one of the XXXI Group of the 24th artillery Regiment G.a.F. and the 4th Army Army Artillery Grouping. These were used in the French Campaign, the defense of Naples and in the defense of the Sicilian coast. Another 16 guns on a shielded coastal mount were supplied to 4 coastal batteries of the Regia Marina, manned by MILMART personnel. Some guns remained in service in the post-war period and were retired in 1959.