Krupp Räumer S
One of the most bizarre vehicles created during the Second World War is the Räumer S, a massive 130-ton machine built by the German company Krupp. It is comprised of two separate halves, connected in the centre and able to articulate, each end is powered by its own engine.
Germany’s rapid re-armament from 1934 onwards focused mainly on ground warfare capabilities, along with a well-equipped air force to support the army on the battlefield. With the rapid acquisition of large numbers of tanks and other armoured fighting vehicles, the German Army command recognised the need for a specialised mechanical mine clearing system with the ability to keep up with armoured spearheads in the field.
In September 1940 the General Army Office (AHA) issued a formal requirement for a heavy mine-clearing vehicle, and on the 16th of that month the Weapons Office ordered a prototype from the Alkett group of companies. Later, the Krupp conglomerate was also invited to respond to the design proposal.
The design concept had strict parameters: the vehicle should be armoured, self-propelled and fitted with rollers that could clear a path three metres wide. It was not to weigh more than 40 tons, and no taller than 2.7 metres, wider than three metres and no longer than 10 metres. The crew had to be totally protected from artillery fragments, small arms fire and naturally, the blast from detonating mines.
Both companies proceeded with their separate design proposals, but experienced repeated and prolonged delays due to problems sourcing some components, and a lack of urgency on part of the government and German Army towards some projects like these. The Alkett design was presented to the general staff in August of 1942, but this prototype, which was known as the VsKfz 617 Minenräumer, was deemed unsatisfactory, and work was suspended on this vehicle by the company.
Krupp showcased their competing design in September 1942, and this prototype was also judged to be unsuitable but enough redeeming features were found for further development to be authorised.
Krupp developed their original proposal into the Räumer S, and this new design was much larger and heavier, but was an innovative blueprint that promised great efficiency if manufactured according to Krupp’s new specifications. The new design plans were forwarded to the Weapons Office in June 1943, and these were approved for prototyping shortly thereafter.
Construction on the prototype proceeded slowly, and further delays occurred when the Krupp factory in Essen was bombed, which necessitated the relocation of the project to a facility near Hillersleben. The project vehicle was shown in an incomplete state to the general staff on the 10th August 1944, and although Krupp promised to have the prototype finished by September, it was not shown to the Weapons Office as completed until November 1944.
With Germany obviously losing the war by 1944, any urgency for the project ceased as it was obvious that no more large-scale mechanised offensives were going to be conducted again by the Wehrmacht, and the prototype never left the Hillersleben facility. It was captured intact by the United States Army in 1945, and taken to Paris for testing.
Due to a lack of records the vehicle fades from history at this point, but one fragment of an American assessment of the Räumer S speculated that the vehicle could also tow a trailer for mine clearing duties, to enhance the total area being cleared of mines.
The Räumer S was an innovative concept, and Krupp were able to finalise a design that fit well within the technical hurdles they were trying to overcome. For crew safety and battlefield mobility a ‘penny-farthing’ concept was used for the vehicle wheels, which were nearly three metres in diameter.
The Räumer S was designed as having two cabins with an axle each, and these segments were joined by a pivoting pin, which swivelled when impelled by hydraulic cylinders.
Each half of the vehicle was equipped with its own power plant, and had a separate driving station that allowed the Räumer S to be driven either forward or in reverse. This was done because the turning circle of the vehicle was overly large, and having two driver stations allowed tactical retreats to be made in relative safety.
The crew consisted of eight personnel, one driver and seven observers/sappers. All crew were seated on sprung seats, and the crew pods had plating to 25 mm in thickness – the high ground clearance of 1.4 metres along with the armour and sprung seats ensured the crew did not suffer any ill-effects from mines detonating in close proximity.
The dimensions of the Räumer S were certainly impressive, and far exceeded the original specifications outlined in the 1940 design proposal. The vehicle had a length of 15.63 metres, a height of 2.93 metres and the different lengths of the two axles (this was done to increase the total of the ground area covered in mine-clearing operations) meant that the Räumer S had a wheel-track width of 3.3 metres.
The total weight of the Räumer S was a staggering 130 tons, and this weight reached the high ground pressures needed for triggering pressure-sensitive mines.
The wheels were 2.7 metres in diameter, and had a width of 530 mm. Each wheel was fitted with massive rubber pads up to 15 centimetres in thickness, and each axle had a very long suspension travel. This was necessary because a wheel could be blown up to half a meter in the air by the blast of a mine, or suddenly drop up to a metre into a mine crater, while still supporting the vehicle body.
The Räumer S was completely unarmed, though the crew had provisions to carry their personal weapons in the vehicle cabins.
The vehicle was fitted with two Maybach HL-90-P-20-K engines, which produced 350 BHP each, with one engine in each of the vehicle’s halves. It was capable of travelling at 15.5 mph (25 km/h) on the road, and operated at 2.5-5 mph (4-8 km/h) when in mine clearing mode.
The German war effort in the Second World War is littered with examples of weapon systems proposals that either never came to fruition, entered service too late to provide a technical advantage over the enemy, or employed in numbers too small to make any appreciable impact on the course of the conflict.