Not a very commonly known off road propulsion method is the Screw Propelled Vehicle or ‘SPV’. The idea of having two large auger type cylinders on each side of the vehicle with a corkscrewing blade down the length will give traction over most types of terrain and being very effective over unmade and boggy ground, on ice and deep snow the propulsion method excels.
The idea has been around since 1899 and was the brainchild of Jacob Morath a Swedish native who moved to Missouri in the US in 1868. The original vehicle design was for agricultural work such as ploughing, with the screws breaking up roots and loosening the ground as it advanced.
One of the first screw-propelled vehicles that was actually built was designed by James and Ira Peavey of Maine, USA. It was patented by Ira Peavey in 1907. The Peaveys’ machine had two pairs of cylinders with an articulation between the pairs to effect steering. At least two prototype vehicles were constructed: one was steam powered the other used a gasoline engine. The prototypes worked well on hard packed snow but failed in soft powder because the flanges had nothing to grip into. The machine was designed to haul logs, but its length and rigid construction meant that it had difficulty with the uneven winter roads for which it was intended.
In the 1920s the Armstead Snow Motor was developed, this was used to convert a Fordson tractor into a screw-propelled vehicle with a single pair of cylinders. A film was made to show the capabilities of the vehicle as well as a car fitted with an Armstead Snow Motor. The film clearly shows that the vehicle copes well in snow. Steering was achived by having each cylinder receive power from a separate clutch, which depending on the position of the steering gear, engages and disengages resulting in a vehicle that is relatively maneuverable. The promotional film of the time showed the Armstead Snow Motor hauling 20 tons of logs with relative ease.
In the 1940’s the “SPV” was looked at again for rapid deployment for a small force of troops in hard to access land regions. Geoffrey Pike was the man behind the idea that was originally rejected, however in October 1941,Lord Louis Mountbattenbecame Chief of Combined Operations and Pyke’s ideas received a more sympathetic hearing. Mountbatten became convinced that Pyke’s plan was worthwhile and adopted it. The scheme became known as Project Plough with many high-level conferences dedicated to it. Pyke was seconded to the US to develop the vehicle but due to lack of understanding between the design parties the idea was dropped in favour of tracked variants.
In 1944, Johannes Raedel, a soldier of the German Army and veteran of the Eastern Front invented his schraubenantrieb schneemaschine (screw-propelled snow machine). Raedel had seen the problems of operating tracked vehicles in the deep snows of Russia where a tank would dig out the snow under the tracks leaving the tank stuck on the snow compressed under the hull. Using whatever materials were available, he built a working prototype during the period of 10 February 1944 to 28 April 1944. It was tested extensively. It was very slow, but it could pull one ton. It also possessed good climbing capabilities. It would penetrate about 30cm into the snow, but no more. Unfortunately, Raedel’s machine never went into production.
The Amphibian Idea
The threaded cylinders are large enough to ensure a substantial area of contact and buoyancy. Being lightweight, the cylinders may conveniently serve as floats and the thread acts as a propulsion blade when in water enabling this arrangement to be used in the design of an amphibian vehicle.
In 1969, after several attempts the Chrysler Motor Company produced the Riverine Utility Craft (RUC) for the Navy in 1969. The RUC travelled on two aluminium cylinders, 39 inches (991 mm) in diameter, reaching impressive speeds of 15.7 knots (29.1 km/h) on water and nearly 25 knots (46 km/h) on marsh land. Again, however, speeds on firm soils proved disappointing, reaching only 6.7 km/h and crossing dykes proved difficult, with the vehicle usually getting stuck and in need of recovery.
In the 1960s, Joseph Jean de Bakker was the entrepreneurial owner of the De Bakker machine factory in the southwest of the Netherlands. He was also a keen fisherman, but he did not want his fishing time to be constrained by the vagaries of the tide. His solution was the Amphirol, a screw-propelled vehicle. The Amphirol was able to convey him over the sticky clay revealed by the outgoing tide and to swim in water at high tide allowing his fishing day to be prolonged.
With a top speed of 12km/h (6.5 knots) on mud and 10 km/h (5.4 knots) in water, the vehicle was assessed to be acceptable. Power was generated by two modified DAF 44/55 variomatic transmission units; this made possible the significant innovation that the flanged cylinders could be deliberately driven in the same direction so that the vehicle could crab sideways on dry land at the alarming speed of 30 km/h (16 knots). When travelling sideways, moving the front of the cylinders so that they are no longer parallel controls the steering, although the turning circle is quite large.
Today, modern vehicles widely known as amphirols, perform specialised tasks such as ground surveying, for grooving the surface of newly drained dikes to assist drying, and to carry soil-drilling teams etc.
The British Ice Challenger exploration team used a screw drive in their Snowbird 6 vehicle (a modified Bombardier tracked vehicle) to traverse the ice floes in the bering Straits. The rotating cylinders allowed Snowbird 6 to move over ice and to propel itself through water, but the screw system was not considered suitable for long distances, and the cylinders could be raised so that the vehicle could also run on conventional caterpillar tracks. The Ice Challenger website says that the design was inspired by a Russian vehicle used to pick up comonaughts who landed in the tough Siberian worldliness, this was quite probably the ZIL 2906 that was built in the 1960’s for this purpose.
Russian inventor Alexey Burdin has come up with a screw-propulsion system “TESH-drive Transformable Worms”
More recently, with the ever growing demand for commodities whilst refinery operational footprints remain within set boundaries, mud farming with the larger machines with deep profile penetration capacity (termed Mud-Masters by their manufacturer) has proven to be an efficient method for high intensity tailings management within the mining industry.
Check out this video of SPV in action …