How Screw-Drive Vehicles Work

Screw-Drive Vehicles History
A closer view of the screw-like threads on the 1926 Fordson screw-drive tractor.
A closer view of the screw-like threads on the 1926 Fordson screw-drive tractor.
Photo courtesy of Killiondude

The record is a bit sketchy when it comes to these machines' beginnings. But among the first-published designs for a screw-drive vehicle was that of Jacob Morath, a Swiss immigrant to the United States who patented a twin-screw ploughing machine in 1899.

Perhaps one of the most highly exposed of these not-so-well-known screw-propelled machines was the Armstead Snow Machine, also known as the Snow Devil. A highly circulated online video shows this screw-driven machine performing various feats in deep snow that confounds other means of transportation -- including one poor horse.

For all its skill in wet snow, the Armstead, a Fordson tractor conversion, apparently had some difficulty in extreme northern climes. The cold, dry snow of Alaska gave the machine a hard time, according to Alaska's Fountainhead Antique Auto Museum, which acquired a number of the machines and their stories [source: Fountainhead Antique Auto Museum].

Military forces have also shown at least a passing interest in screw locomotion over the years. Nazi Germany investigated a screw-propelled machine to navigate the snowy Eastern front -- tanks would often sink in the snow and get stuck. The screw-driven machine, invented by Johannes Raedel, never went into production. The United States military briefly considered a screw-drive design for its "Weasel" small transport for Special Forces during World War II before settling on a tracked design.

And during the Cold War, the then-Soviet Union's ZiL automotive company built one of the most intimidating screw-drive vehicles of all. The ZiL-29061, with its angular lines and massive twin drive screws, looked like a vehicle straight from the apocalypse. You can find videos of it, too, circulating online. The ZiL was built to fetch Soviet cosmonauts after they landed in places that were for other vehicles too forbidding, like the far reaches of Siberia.

You can even find screw-drive vehicles in use today. They're used in industrial and mining applications to traverse sloppy terrain and to break up muddy expanses of clay so that it dries more quickly.

To find out about screw-drive vehicles' performance capabilities -- what they can and can't do -- read the next page.