One of the oddities of the war. Just posted a pic of a model of one in the modelling forum so here is a potted history.
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In 1936, Rheinmetall Borsig AG was approached by the German army general staff to build a special amphibious tracked vehicle for landing operations. The tractor would be able to two behind it a floating trailer capable of accommodating vehicles or other cargo weighing up to 18,000kg. On water the tractor would function as a tug for the floating cargo trailer. After landing the tractor would still have to move the trailer to a safe place to unload the cargo.
Rheinmetall tackled the project and the product became known as the Land-Wasser-Schlepper (land-water tractor) or LWS. The LWS was actually and simply a motor tug built with tracks. It was a large and strange machine that nonetheless turned out to be a rugged vehicle (or boat?). There were two long sets of tracks, one on the flat bottom on each side of the LWS. There were four pairs of road wheels suspended from leaf-spring suspensions on each side. The boat part of the LWS had a clean, pronounced bow, and on top there was a compartment for the crew of three and extra room for another 20. The funnel-like structure on top of the cabin was actually the engine's air intake. Two large propellers were installed at the rear, or stern, for propulsion in water. To make the LWS more boat-like there were portholes on both sides of the crew cabin.
On land the floating trailer looked like a large slab-sided vehicle, and was supported by wheels on one forward axle and two rear ones. On the back side a ramp could be opened for unloading. A typical load was an SdKfz 9 18-tonne halftrack, and the crew would be housed in the LWS for the aqueous leg of the journey.
The LWS and trailer idea was tried and tested quite slowly and leisurely until "Seelöwe" (Operation Sea Lion, the invasion of Great Britain) was to become reality after the fall of France. The LWS and trailer could certainly be used in such an amphibious operation, but they were more suited for calmer waters of inland water bodies, not the tempestuous English Channel. The LWS program was for a while carried out with more urgency, but was never materialized. By 1941 the project was dropped, when the prospect of Seelöwe was overshadowed by the much more serious Operation Barbarossa (invasion of Russia).
One disadvantage of the LWS was the lack of armour, and armour was deemed necessary for any amphibious operations. The floating trailer was also thought to be too cumbersome and clumsy so a new scheme was devised. The overall structure of the LWS was kept, but the new vehicle had the track work and suspension of the ubiquitous PzKpfw IV to support a lightly armoured superstructure.
Two new vehicles, called Panzerfähre or PzF, were built and designed to take a large pontoon between them to transport a tank or other cargo. Thus the PzF would act as a ferry rather than a tractor. However, the program was cancelled in 1942 after the two prototypes were built and tried. A pre-production of seven LWS's were built and they served on the Eastern front. After the war the LWS was taken by the British to England for technical assessment.
http://www.diggerhistory.info/pages-...hib/german.htm
