Editing Operation Sea Lion (section)

=== Specialised landing equipment ===
As part of a ''Kriegsmarine'' competition, prototypes for a prefabricated "heavy landing bridge" or [[jetty]] (similar in function to later Allied [[Mulberry Harbour]]s) were designed and built by [[Krupp]] Stahlbau and Dortmunder Union and successfully overwintered in the North Sea in 1941–42.<ref name=Bonnard>''Alderney at War''. Brian Bonnard. 1993. {{ISBN|0-7509-0343-0}}. pp. 106–08. Alan Sutton Publishing.</ref> Krupp's design won out, as it only required one day to install, as opposed to twenty-eight days for the Dortmunder Union bridge. The Krupp bridge consisted of a series of 32m-long connecting platforms, each supported on the seabed by four steel columns. The platforms could be raised or lowered by heavy-duty winches in order to accommodate the tide. The German Navy initially ordered eight complete Krupp units composed of six platforms each. This was reduced to six units by the autumn of 1941, and eventually cancelled altogether when it became apparent that Sea Lion would never take place.<ref name=Schenk139>Schenk, p. 139</ref>

In mid-1942, both the Krupp and Dortmunder prototypes were shipped to the [[Channel Islands]] and installed together off [[Alderney]], where they were used for unloading materials needed to fortify the island. Referred to as the "German jetty" by local inhabitants, they remained standing for the next thirty-six years until demolition crews finally removed them in 1978–79, a testament to their durability.<ref name=Schenk139 />

The German Army developed a portable landing bridge of its own nicknamed ''Seeschlange'' (Sea Snake). This "floating roadway"  was formed from a series of joined modules that could be towed into place to act as a temporary jetty. Moored ships could then either unload their cargo directly onto the roadbed or lower it down onto waiting vehicles via their heavy-duty booms. The ''Seeschlange'' was successfully tested by the Army Training Unit at Le Havre in France in the autumn of 1941 and later chosen for use in ''[[Operation Herkules]]'', the proposed Italo-German invasion of [[Malta]]. It was easily transportable by rail.<ref name=Schenk139 />

A specialised vehicle intended for Sea Lion was the ''[[Landwasserschlepper]]'' (LWS), an amphibious tractor under development since 1935. It was originally intended for use by Army engineers to assist with river crossings. Three of them were assigned to Tank Detachment 100 as part of the invasion; it was intended to use them for pulling ashore unpowered assault barges and towing vehicles across the beaches. They would also have been used to carry supplies directly ashore during the six hours of falling tide when the barges were grounded. This involved towing a ''[[Karl Kässbohrer Fahrzeugwerke|Kässbohrer]]'' amphibious trailer capable of transporting 10–20 tons of freight behind the LWS.<ref name=Schenk132-133>Schenk, pp. 132–33</ref> The LWS was demonstrated to General Halder on 2 August 1940 by the Reinhardt Trials Staff on the island of [[Sylt]] and, though he was critical of its high silhouette on land, he recognised the overall usefulness of the design. It was proposed to build enough tractors that one or two could be assigned to each invasion barge, but the late date and difficulties in mass-producing the vehicle prevented this.<ref name="Schenk132-133" />