It was based on the Ford Model T, but with a longer wheelbase, and a heavier frame and rear axle, giving it a rating of 1 short ton (0.91 t).

When the first three units were produced in 1917, the Model TT was sold as a chassis with the buyer supplying a body.

Although Ford ... was a pacifist, he was ... happy to supply the US Army with more than 12,000 of these vehicles,..."[3] and: "There was no civilian production of the Model Ts between 1917 and 1918."

Further on, Ware writes: "The Model T was widely used by the US and British armies during World War I as a staff car, ambulance, van and cargo truck, even as an artillery tractor, for which application the truck was fitted with twinned rear tyres.

The wheelbase of the Model TT is 125 inches (3,175 mm), compared to 100 inches (2,540 mm) for the Model T. It was often equipped with an accessory gearbox, such as the Ruckstell or Jumbo gearboxes, which allow the truck to have intermediate gears between low and high, useful for hill climbing.