by Erik Ettrup

The M19 was a very advanced fully-automatic 5cm mortar. Due to it's size it was only used in bunkers, mainly in the Atlanticwall.

History
The production of the first M19 probably started in 1937-38. The first known examples were installed in the Westwall, in the so-called "B-werke". They were the German answer to the French automatic-mortar mle1935 on the Maginot-line. Only some 30 mortars were built for use in the Westwall. During the construction of the Alantikwall, the M19 were put back to production. Due to the high production cost and time, only the most important areas, like submarine bases and large coastal batteries were equipped with the M19. A very few examples were mounted in the Ostwall defenceline in Poland, 1944.
In the years between 1937 and 1945, only 98 of these incredible weapons were made.

Description
The M19 was mounted inside armoured copulars. Only a few cm's of the barrel was visible from the outside. The whole weapon-platform could be lowered 50 Cm's, an a hatch could seal the opening for the barrel. A retractable periscope could also be used when the weapon was lowered. The copular which had a inside diameter of only 2 meters, were usually manned by 3 soldiers. One of them controlled the weapon alone. With his right hand, he could turn the weapon-platform 360 degrees. With his left hand, he adjusted the elevation. His left foot was used to lock the platform, while the trigger was on his right foot. the 2 others worked with the loading system.
The loading system could be manually operated, or it could be switched to electrical loading. Inside the ammunition room below the copular, several men worked with refilling clips for the mortar. They were placed in an elevator which brought them up to the platform. At manual mode, he loader would place a clip in the weapon, when it was empty, the second loader would remove it, and place the empty clip in the "return elevator". If the weapon was switched to automatic, a 5KVA generator would replace the loaders in the copular. This however, would use all ammunition within minutes, and the weapon would suffer from enormous strain.
The automatic fire was only used in emergencies

The R-633
The bunker type R-633, was the only standarized regelbau for the M19. It had 6 rooms, 3 of them for the M19 equipment, and 3 for the personell. A R-633 was manned by 14 persons, half of them manning the M19.
Standard ammunition storeage inside a R-633, was 3944 rounds. There were a few different copulars used. In the R-633, the 424p1 was used.

Technical data - weapon
Weight: 220 Kg
Calibre: 50 mm
Ammunition: Same as the 900G. LeGrW36 werfer.
V/o: 44-83 M/sec.
Range: 50-750 Meters
Rate of fire (manual) max 60 Grenades pr minute
Rate of fire (electrical) 30-120 grenades pr minute (adjustable on the weapon)
Power consumption: 5KVA

Technical data - platform
Traverse: 360 degrees (11 degrees pr. second)
weapon Elevation: +48 / +87 degrees
Platform elevation: 50 CM

Technical data - Copular 424p1
Height: 3,4 M
Weight: 39000 Kg
Inside diam.: 1,7-2 M
Armour: 250 mm

Examples of places where M19 was used
3 x R-633 Placed at MKB11/504 (Coastal battery with the "B-turret" from Gneisenau), Norway
1 x SK placed at the Submarinebunker belonging to 6th & 7th U-Flotille in St-Nazaire,France.
2 x R-633 in the harbour of Oostende, Belgium.
1 x R-633 in "Infanterie-stützpunkt Agger-Dorf" Denmark.
2 x R-633 in "Festung Oder warthe Bogen", Poland.

M19 at the Wehrtechnische Studiensammlung, Koblenz


.