As part of a Kriegsmarine competition, prototypes for a prefabricated "heavy landing bridge" or jetty (similar in function to later Allied Mulberry Harbours) were designed and built by Krupp Stahlbau and Dortmunder Union and successfully overwintered in the North Sea in 1941-42 [REF].
A specialised vehicle intended for Sea Lion was the Landwasserschlepper (LWS), an amphibious tractor under development since 1935.