Self-Propelled Mortar Carriers II

SdKfz 251/2 Mortar Carrier

The SdKfz 251 was developed into a range of different purposes, from ambulance duties to anti-tank roles. By late 1944, around 16,000 vehicles had been built to serve in no fewer than twenty-three different roles. Depending on the role, each version had a different length of service life, but if they were capable of continuing to operate they remained in use. In fact, examples were still in operation right until the last days of the war at a time when fuel was extremely scarce. One of the earliest variants to be produced was the Sdkfz 251/2, which was the mortar-carrying version, weighing 8.64 tons and equipped to carry the 8cm GrW34 mortar. Being open-topped, the weapon could be fired from within the vehicle, firing forward, and a separate baseplate allowed it to be dismounted for use from prepared positions. The vehicle in this role was operated by a crew of eight, available in the heavy platoon and known as Great 892 (Equipment 892). It carried sixty-six rounds of ammunition ready to use and was supported in turn by the SdKfz 251/4 version, which could carry resupplies of ammunition or even tow the heavy GrW42 12cm mortar.

The other half-track vehicle developed into a mortar carrier was the SdKfz 250, which was built by the company of Bussing-NAG, which developed the armoured body, and several other manufacturers including Weg-mann and Deutsche Werke. Although the design had been thoroughly tested in the field throughout 1939, there were insufficient numbers ready to enter full operational service on the outbreak of war. In fact, the SdKfz 250, originally referred to as Leichte Gepanzerte Kraftwagen, did not enter service with the German Army properly until 1940, by which time it was known as the Leichte Schutzenpanzerwagen (light infantry armoured vehicle). Although it was not in service for the Polish campaign, there were sufficient numbers in service to be used during the attack against Holland, Belgium and France, where they were used in roles such as reconnaissance, command and communications. After this initial battle-proving deployment, the SdKfz 250 went on to see service on all fronts during the war, including North Africa, Italy and Russia.

The basic model was an armoured personnel carrier designated as the SdKfz 250/1, operated by a crew of two (driver and commander). In this role it was capable of carrying four fully-equipped troops with support weapons, such as crew for mortars or machine guns. This version was armed with two machine guns, such as the MG42, for which some 2,000 rounds of ammunition were carried. The basic version SdKfz 250 was almost 15ft in length, 6.4ft in width, but the height varied according to the role in which it was serving and the armament carried. The standard version had a combat weight of 5.5 tons, but, again, this varied according to armament and other equipment, such as the mortar carrier which weighed 5.61 tons. The armour thickness was from 8mm minimum to 15mm maximum.

The vehicle in all its variants was powered by a Maybach HL42 TR KM six-cylinder water-cooled inline petrol engine, which developed 100hp at 2,800rpm and gave a top speed of just over 40mph on roads. The vehicle had an operational range of over 180 miles on roads and it could negotiate vertical obstacles up to 15in, ford water obstacles shallower than 27in and scale gradients of 40 degrees. The front wheels were not ‘driven’, being used for steering purposes only. The automotive power was to the front drive sprockets on the tracks and the suspension was of the FAMO type, and whilst the vehicle was itself efficient it was somewhat complicated to maintain. This was a telling point in the sub-zero conditions on the Russian Front after 1941. In total, twelve variants were developed from the basic version and included an antitank gun version, specialist engineer versions, signals vehicles, ammunition carrier with ordnance troops and was even used by the Luftwaffe. Most, but not all, versions of the SdKfz 250 were open-topped, which was perfect to allow fire support weapons such as the GrW34 8cm mortar to be mounted and create a variant known as the SdKfz 201/7 or Great 897 (Equipment 897). These were operated by a crew of five and available to the fourth platoon of the Leichter Panzer Aufklarungs, or light armoured reconnaissance vehicles. A total of forty-two rounds of ammunition were carried on the vehicle ready to use and the mortar could be dismounted to be used to provide fire support in prepared positions. It was supported by a version termed munitionsfahrzeug (ammunition vehicle), which was operated by four men and carried sixty-six rounds of ammunition to resupply the mortar carrier. It was armed with two machine guns for self-defence with 2,000 rounds of ammunition.

In addition to using its own standard mortar-carrying vehicles, the German Army also converted a number of captured French armoured vehicles to the role of self-propelled mortar carriers. These they armed with either German service 8cm sGrW34 mortars or captured French-built Brandt weapons. French tanks such as the AMR35 had their turrets removed and the chassis converted to other roles such as self-propelled guns and mortar carriers. In May 1940, the French Army had about 200 AMR35 tanks in service, mostly armed with a 37mm gun in a fully traversing turret, but there were also other variants. After the French surrender, all surviving examples and variants captured by the Germans were converted into other uses, which included carrier vehicles for the standard German Army 8cm sGrW34 mortar. In this role they were designated as 8cm schwere Granatewerfer 34 auf Panzerspahwagen AMR35(f), which identified it as a heavy armoured self-propelled mortar carrier.

The conversion was achieved by first removing the upper superstructure including the engine covering, and this was replaced by an open-topped fighting compartment into which was mounted an 8cm GrW34 mortar fitted on a race-ring mounting to allow it to be fired in any direction without having to manoeuvre the vehicle. The rear of the compartment was open but could be closed off with a door to protect the crew. The conversion gave it a larger profile than the original design but the engine and all other automotive parts and road wheel layout remained unchanged. This gave the vehicle a road speed of 31mph and an operational range of 120 miles. It was operated by a crew of four, which included the driver, and a secondary armament of a single 7.92mm calibre MG34 machine gun was fitted for self-defence. A supply of ready-to-use ammunition was carried on the vehicle and resupply vehicles would have brought forward replenishment stocks. Records show that around 200 such vehicles were converted to this role and used only in France, where they could be deployed in response to threats. The conversion would have been completed at workshops in France, but it is not clear if any of these vehicles participated in the fighting after the Allied landings in Normandy from 6 June 1944 onwards.

It would seem likely these would almost certainly have been deployed at some point against the Allies because it would make no sense to develop such weapon systems and not use them. It may be that some of these self-propelled mortar vehicles were used in the fighting during the Normandy campaign, but due to the low production numbers they have been overlooked in favour of the more widely-used vehicles such as the true self-propelled guns and tanks. The person responsible for developing these systems and other selfpropelled weapons was Major Alfred Becker, who was a professional soldier, having served in the First World War. He was an engineer who excelled in developing hybrid systems such as these, using captured stocks of enemy equipment. He commanded the Sturmgeschutz-Abt 200, equipped with selfpropelled guns of his design, as part of the 21st Panzer Division, seeing much action in Normandy. He served with distinction and developed other systems until his capture in December 1944.

One of the most unusual conversions to serve as a mortar carrier was based on the French SOMUA MCL half-track personnel carrier, which became known as the Mittlerer Schutsenpanzerwagen S307(f), work on which began in 1943. The vehicle was modified to its new role by mounting two rows of eight barrels of 81mm captured French Army mortars stacked on a mounting to the rear of the vehicle. The tubes were pre-loaded and could be fired simultaneously to produce an instant bombardment. Reloading the tubes would have taken time and rate of fire would have been a lot slower than using a conventional mortar firing from a prepared position. In total some sixteen of these vehicles were available in 1944, but their fate is not known. A heavier version was produced, also based on the SOMUA MCL, which mounted twenty barrels of 81mm Brandt mortars in a similar array, and this was known as the Schwerer Reihenwerfer auf SPW SOMUA S303(f). These vehicles served in France, but, again, it is not known conclusively if they were deployed in action against the Allies after June 1944.

Captured armoured vehicles were dispatched to various theatres of operations, including Finland and Norway. Others such as the French Char B-1 bis, known in service with the German Army as the Panzerkampfwagen B-2 740(f), were sent to the Channel Islands and the Eastern Front, which represented the opposite extreme edges of the territory under German occupation. In the Channel Islands, some French tanks had their turrets removed to be incorporated into defence plans. Other vehicles which could have been converted to use as mortar carriers included the UE630, which the French Army used as a transport vehicle for supplies, and the Unic-Kègresse half-track, yet despite their suitability neither these nor apparently any other French vehicles were armed to serve as self-propelled mortars carriers.

The French Army had never deemed it necessary to develop a self-propelled mortar system using any of the weapons in service; after all they had good artillery and armoured units. The Italian Army did not develop a selfpropelled mortar system and relied on artillery and the mortars used by the infantry units. After 1943, when Italy capitulated to the Allies, the German Army seized many armoured vehicles and took these into service. Unlike the French vehicles which they converted to other uses, the Italian vehicles were used in their primary roles. The Soviet Red Army did not develop a selfpropelled mortar system either and relied on self-propelled guns and vehicles which towed the heavy calibre mortars on wheeled carriages. The Japanese Army did experiment with self-propelled mortars for a while and developed the Type 4 Ha To. This used a Type 4 Chi-To medium tank which was converted to allow a 300mm calibre Type 3 heavy mortar to be mounted to fire forward. It could fire a 374lbs HE bomb out to ranges of 3,300 yards, but the design was unstable and the vehicle proved liable to toppling over due to its height. In the end only three prototypes of the Ha To were produced and these never saw combat service.

Type 4 Ha To

British and Commonwealth forces did not show much interest in developing a self-propelled mortar version based on an armoured vehicle design. Some feasibility experiments were conducted to examine the viability of producing such a variant, but ultimately the research did not lead to the introduction of a vehicle-mounted mortar in the same way as used by the American and German armies. One experiment which did lead to the production of a self-propelled version of the British 3in mortar was based on the Universal Bren Gun Carrier. This was developed by the Australian Army, which had already modified some Universal Carriers to mount 2-pdr anti-tank guns, and using this as a starting point they fitted a 3in mortar to the vehicle. The weapon could be fired directly from the vehicle or dismounted and used from a prepared defensive position. The mortar had a full 360-degree traverse capability if required, which meant the vehicle did not have to manoeuvre to alter the range of traverse beyond the angles which could be achieved in the bipod mounting. In terms of range, this configuration was comparable to the standard infantry mortar and fired the same bombs. In the end it was never taken into service with the Australian Army, but around 400 examples are understood to have been produced and these were sent as part of the military aid to support the Nationalist Chinese Forces of Chiang Kai Shek in the fighting against the Japanese.

It seems strange that the British Army should not pursue the development of a self-propelled mortar vehicle, especially when it developed a range of specialist vehicles for other roles to clear minefields and close support tanks armed with large calibre guns. These were developed in the build-up for the invasion of Europe to support the landings. They were known as ‘Hobart’s Funnies’, after Major General Percy Hobart who thought up some of the designs. Hobart was a military engineer who had served in the First World War, seeing action in France. During the 1920s, he developed an interest in tank designs and armoured warfare tactics. He retired in 1940 under duress, following a conflict of opinions concerning his designs for armoured vehicles and their role. Hobart initially joined his local Home Guard unit, but in 1941 he was re-instated and given the job of training the 11th Armoured Division. Further positions followed and in 1942 he was given the role of training the newly-created 79th Armoured Division. After the disastrous failure of Operation Jubilee, the Allied attack against Dieppe on 19 August 1942, where none of the tanks were able to get off the beach, he set about developing a series of specialist armoured vehicles designed to support future amphibious landings. What Hobart developed included bridge-laying vehicles, flails to breech minefields and flame throwers. These were to prove vital during the D-Day landings and campaigns across Europe. For some reason self-propelled mortars were not developed. One can only conclude that with SPGs such as the Sexton, with its 25-pdr field gun, and the M7 ‘Priest’, with its 105mm gun, Hobart did not feel it necessary to build a design around the British 3in mortar.