The Siebelfähre (Siebel Ferry) were conceived as one of several types of landing craft intended to support the German invasion of England, Operation Sea Lion. They were constructed by combining two large bridging pontoons with a cargo deck to form a catamaran arrangement. Power was provided with either truck or aircraft engines located within the pontoons, and a small pilothouse was constructed in the center. The ferry could carry any vehicle in the German inventory, including Tiger tanks. The stability of the catamaran configuration was not lost upon the Luftwaffe, who converted several into flak barges after the cancellation of Sea Lion.
Here is a beautiful series of color photographs taken by Carl Rosenquist on 13AUG42. The occasion was a review of several Siebel Ferries on Lake Ladoga by German and Finnish officers. Photographs are held by SA-Kuva, the Finish National Archives.
WHENEVER ANY FORM OF GOVERNMENT BECOMES DESTRUCTIVE OF THESE ENDS (LIFE,LIBERTY,AND THE PURSUIT OF HAPPINESS) IT IS THE RIGHT OF THE PEOPLE TO ALTER OR ABOLISH IT, AND TO INSTITUTE A NEW GOVERNMENT― Thomas Jefferson