Fort Sill, OK
Field Artillery Museum
Lat : 34.65680 / Long : -98.37730
General comments on this surviving gun :
Identical items in the same location :
Items covered by this file :
Historic context :
Inspired by the Russia - Japan wer experience, where new techniques of siege war had been improvised, Germany was clever to develop from 1909 a modern family of 3 small mortars, equipped with recoil recuperators, with calibers 25cm, 17cm and 7.5cm.
The 175 mm caliber of the '17 cm mMW (a/A)' made by RheinMetall ('mMW' = 'mittlere MinenWerfer' = medium mine launcher) was the intermediate one. It was tested in 1912 and introduced in the army units in 1913, two years after the 25cm sMW a/A heavy mortar.
Compared to the heavy mortar that was designed as an offensive weapon for the pionneers assaulting fortresses from short distance, thus needing high destructive power, the medium mortar as at the contrary designed for the fortresses defence against heavy mortars (supposed to be developped too by the ennemy). This weapon mission was therefore to send explosive charges a bit lighter (50 kg instead of 100 kg) at longer range (800 m instead of 560 m).
The shells had a copper belt pre-engraved with 6 guiding grooves, and were introduced in the rifle bore from the muzzle, over a propulsive load competed depending on the target. Le firing was started by a friction starter (later electric) threaded in the barrel base.
116 such mortars of the original version (later named 'a/A' = alte Art = old version) were available in August 1914 in the pionners units, and participated to the siege of the Belgian fortress of Antwerp. Just as the 25cm heavy mortar, the medium mortar was found particularly well adapted to the trench warfare from the end of 1914, in first line or close to it, in defensive positions destruction missions.
As a proof of this success, the number of mMW climbed to 475 a little more than one year later (end of 1915) and continued to increase throughaout the war. An improvement was introduced in 1916 with an elongated tube for an increased range.
Technical data :
- Complete description : 17cm Middle trench mortar old mark
- Design year : 1913
- Calibre : 175.00 mm
- Weight in firing position : 525 kg
- Weight for transportation : 819 kg (with the 204 kg platform and the wheels)
- Tube length in calibres : 3.80
- Grooves : 6 width 30mm, 7 degrees angle
- Projectile weight : 54 kg
- Initial speed : 87 m/s
- Fire rate :
- Range : 768 m
- Elevation range : 45 to 75 degrees
- Direction range : 20 degrees total range (360 degrees mounted on the 'rundbettung' platform)