This promotional video showcases the screw-propelled Marsh Screw’s many capabilities, such as torquing sideways in the mud.
Built in conjunction with the Department of Defense, the Marsh Screw could carry a half-ton of troops and supplies on all types of terrain. Powered by a 225ci Chrysler inline six, its two turbine-like screws make a Mississippi marsh looks like a California blacktop, alternating between land and water.
According to Mac’s Motor City Garage, as many as 10 units were thought to have made it into production before the idea was shelved by the U.S. government. It maybe wasn’t the fastest of vehicles, but its off-roading potential was pretty damn incredible.
The top speed in liquified mud was 12.5 MPH and it went down from there. Fully loaded and in muck it was capable of going about 4 MPH. Not exactly fast attack potential there. Military testing documents mention that the steering was erratic and the vehicle was inefficient on hard surfaces. The military also called the required maintenance on the vehicle “excessive.” Whoops! We’re guessing that the slant six was not the maintenance problem but rather the drive systems.
Looking at the technical data, we can see that the Marsh Screw Amphibian weighed 2860 lbs unloaded, had 116 hp and in an interesting twist actually used a Torqueflite transmission behind it that that powered the screw like pontoons that propelled the thing. The coolest part of all? This used one of the very rare all aluminum slant sixes!
Can you believe that a machine like the Chrysler Marsh Screw Amphibian actually existed more than 50 years ago? Crazy!