We’ve seen several snowmobiles built out of Model Ts around these parts – it’s rather a favorite topic of ours – so we were all over the photo David Greenlees recently posted to the excellent thread full of pre-World War II photos on the H.A.M.B. Rather than extend an endless tread over the rear wheels and a bogie and convert the front wheels to skis, as is normally done to snowmobile-ize a Model T, this inventor proposed to dispense with the skis and fully convert a Model T into a tank.

When he posted the photo, David mentioned that this was Walter Christie’s invention, but as we investigated it more, we became suspicious. Walter Christie, he of front-wheel-drive race car fame, did indeed turn his eye toward tanks later in his career, and we could imagine that this was one of his earlier experiments, but in every photograph and drawing of Christie’s tanks, we saw that he made good use of his coil-spring suspension. This Model T tank, on the other hand, does not.

We even read up some on Ford’s two-man tanks, thinking that this may be an early prototype of the handful that Ford built in 1918 out of an order for 15,000 such tanks (the war ended before production could really get started). But this design seems to have even less in common with Ford’s two-man tank than with Christie’s tanks.

A chance encounter with an August 1918 Popular Science article provided the answers we were seeking. Indeed, this was called a two-man tank. Popular Science attributes the design to Charles H. Martin of Springfield, Massachusetts, the same inventor behind the Knox-Martin three-wheeled truck. As a tank, the Model T chassis (still powered by the Model T engine) would have carried 1,200 pounds of armor and two machine guns and would be capable of 12 MPH, making it ideal for “quick dashes into the enemy’s country,” Popular Science wrote.

Interestingly, Popular Science also conjectured that in its final form, the Model T tank would use treads configured to go completely around the vehicle rather than straight forward and back. If Popular Science was correct, then Martin’s tank in its final, armored form would have actually very closely resembled the Ford-built two-man tank. Could Martin have been working with Ford at the time to develop his ideas for a tank? Or were the Martin two-man tank and the Ford two-man tank developed separately?

P.S. Though we aren’t doing a Hemmings Six Degrees of Separation Challenge today, here’s something to chew on: Charles H. Martin was employed by Knox. Knox’s very first factory, according to the Standard Catalog, was in a building formerly occupied by the Waltham Watch Company, which, if you’ll recall, built speedometers based on a design by Nikola Tesla.