| Is Artillery: | yes |
| Obice da 305/17 | |
| Origin: | Kingdom of Italy |
| Used By: | Kingdom of Italy Nationalist Spain |
| Wars: | World War I Spanish Civil War World War II |
| Designer: | Armstrong-Pozzuoli |
| Design Date: | 1908 |
| Manufacturer: | Armstrong-Pozzuoli Vickers-Terni |
| Production Date: | 1914-1917 |
| Service: | 1914–1959 |
| Number: | 30-44 |
| Weight: | Combat: 33.7t |
| Part Length: | 5.80NaN0 L/17 |
| Crew: | 10 |
| Cartridge: | Separate loading bagged charge and projectile |
| Cartridge Weight: | NaNkg (-2,147,483,648lb) |
| Caliber: | 3050NaN0 |
| Rate: | Maximum: 1 round every 5 minutes Sustained: 1 round every 12 minutes |
| Velocity: | 545m/s |
| Max Range: | 17.60NaN0 |
| Recoil: | Hydro-pneumatic |
| Breech: | Interrupted screw |
| Carriage: | Box trail |
| Elevation: | -20° to +65° |
| Traverse: | 360° |
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 defense gun but was later adapted to a mobile siege artillery role.[1] 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 280mm 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 3050NaN0 howitzer. The Inspector General of Artillery chose the design from Armstrong-Pozzuoli, with modifications to the ammunition, and loading system.
The 5.8m (19feet) long barrel of the 305/17 was made of steel and was rifled with 60 left-hand constant twist grooves. Although the overall length of the barrel and breech was 19 calibers, the Italians designated their artillery by the length of the barrel only which was 17 calibers. The barrel was then inserted into a ring cradle which housed two cylinders of the hydraulic recoil mechanism and the pneumatic recuperator cylinder located above the barrel. The barrel was mounted on trunnions towards the middle and the wedge-shaped box trail carriage had a large open space behind the breech to allow for recoil, high angles of elevation and reloading. The weight of the barrel and breech was 12.79t. The 305/17 had an interrupted screw breech and used separate loading bagged charges and projectiles.[2]
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.[4] 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.[5] 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.
In 1937, 5 pieces were delivered to the Nationalists during the Spanish Civil War.[6]
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.[7]