US Army WW1 Type B truck

[Uyraell]

The Commer trucks were basically the UK equivalent of the US Army Type B trucks.

From (my admittedly limited) memory of the relevant info they were box-girder chasses, mounted on double-shackled (ie: "flexible shackles") leaf-spring running fore-aft at rear and transverse at the front, supporting expanding-brake hubs mounted to solid-tired "Artillery" wheels, of 18 to 26 inches in diameter, by approximately 4.5 inches-wide tires, sometimes "dual-wheeled" on the 4 and 5-tonners. Very early photographs have shown the presence of braking-blocks levered against the rims of the rear wheels, though I doubt that feature survived to see use in WW1.

Transmissions were non-syncromesh 3 or 4 speed in the 1.5 to 3-Ton models, and 3-speed only in the 5 tonners, plus reverse. Drive to the rear wheels was usually by chain, although some evidence seems to exist that the lighter-loaded models did employ direct-differential-to-halfshaft in some models.
Towards 1919 there may have been developments with "lockable" differentials, but no clear evidence have I found of that development seeing employ during WW1 itself.

Motors were, iIrc, generally in the 4 to 6 cylinder straight configuration varying between 30 and 50 hp, with side-valves and (again iIrc) down-draught carburettors. Mechanical fuelpumps may have seen employ after 1915, again if recall serves correctly.

Steering was usually (iIrc) by worm-gear and none-too-accurate, even if reliable.

Cabs were often open-sided or wooden roof with canvas weathersheilds instead of doors, which were much more rare; as is common with trucks of that era. Windscreens where fitted were often two-part, upper hinging forwards from the top run, as was also common.

Lighting, where fitted, was usually Carbide or Acetylline Lamps, the electrical system (such as it was) being usually 6-volt, magneto.

Once again, all of this info is "As I recall it" and may be subject to inaccuracies or reproofs, in as much as a more knowledgeable head than mine own may indeed have better information available.

Nonetheless I hope it is of some help, however minor, in your ongoing project, Dave, and yours, Wayne.

Kind and Respectful Regards my friends, Uyraell.