The Rural Roots of the Versatile Jeep

Editor’s Note: This is the third in a series of four articles on the contributions farmers and tractor manufacturers made to winning World Wars I and II. This article originally appeared in Ageless Iron Almanac.

Although historians still debate the true origin of the vehicle that is considered to be one of the greatest weapons brought to bear by the U.S. during World War II, there is little doubt that Minneapolis-Moline contributed to the creation of Jeep-like vehicles.

Years before American Bantam and Willys-Overland began development of the vehicle affectionately dubbed the Jeep by soldiers, Minneapolis-Moline engineers were experimenting with a tractor-like vehicle that could pull artillery or supply trailers as well as transport troops to battle.

Jeep Name Origins

That first Jeep, so named by a Minnesota National Guardsman, proved its worth in moving men and material around. That original machine was put to work at the Guard’s station at Camp Ripley, Minnesota.

The book, A Wartime Report: Food, Too, Fights For Freedom, published in 1944, describes how in 1940 a farm tractor from Minneapolis-Moline was adapted for military use and then tested in maneuvers at Camp Ripley under the collaboration of Adjutant General E. Al Walsh.

“This new Minneapolis-Moline army vehicle wasn’t a crawler tractor, truck, or tank, and yet it could do almost anything and it knew all the answers,” the book states. “Because of this, it brought to mind the Popeye cartoon figure called Jeep, which was neither fowl nor beast, but knew all the answers and could do most anything. The National Guardsmen, therefore, named the Minneapolis-Moline vehicle the Jeep. The Jeep name, therefore, isn’t a contraction of the term General Purpose (GP).”

Other histories pinpoint naming honors on a Sergeant James T. O’Brien of the 109th Ordnance Company, who was so impressed by the UTX’s ability to lug howitzer cannons through mud that he hung a sign painted with the word Jeep from the vehicle’s radiator.

Naming honors aside, the fact is that the innovation Minneapolis-Moline displayed in adapting its model U tractor to military employment did influence the military and subsequent military contractors to create a do-it-all vehicle for war use.

Based On a Model U

Minneapolis-Moline originally designed its innovation, designated the model UTX, to move light artillery. The machine was built with fenders and sometimes cabs co-opted from the ill-fated model UDLX.

Power for the truck originally came from a 41-hp. Minneapolis model DEF 283 cubic inch four-cylinder that was also employed in the Model U tractor.

Minneapolis engineers would later swap out that engine with the company’s 75-hp. model CE 425 cubic inch six-cylinder unit. After use at Camp Ripley, the UTX was sent to the Army’s Aberdeen Proving Grounds in Maryland for evaluation.

The UTX didn’t meet Army requirements during that evaluation, though, since it wasn’t powerful enough to tow heavy artillery or to run down the road at highway speeds. (Top speed for the UTX was around 30 mph.)

Aircraft Tug is Born

Undaunted, Minneapolis-Moline engineers set to work creating a military tractor. The prototype models ZTX and six-wheel model GTX came out of those efforts but never went into production. Yet, those engineers did score with the creation of the model NTX.

This four-wheel-drive truck employed a 44½-hp. Minneapolis model OE four-cylinder engine set on a 1½-ton chassis riding atop 9.00-20 inch tires set apart on a 101 inch wheelbase. The tractor was designed to ride low enough to the ground so it could pass under aircraft wings.

That ability, along with the NTX’s four-wheel-drive capacity, found favor with the Army Air Force, which wanted the unique vehicle to tow aircraft. To give the vehicle speed, engineers put engine power to work through a five-speed transmission rigged with a high-low speed range that provided 10 speeds. Much to the pleasure of the Army, the NTX could zip around airfields and down roads at speeds of over 40 mph.

The NTX was unique not only for its low profile and wide wheelbase but also because its engine featured a fully hydraulic valve train.

Those valves were positioned in the 206 cubic inch engine block to operate horizontally with the cylinder head positioned on the side of the block. Intake and exhaust ports were located on the top of the block. This unique engine configuration was chosen by Minneapolis-Moline engineers because it had far fewer parts than the firm’s other engines.

Approximately 840 (some estimates mention 1,110) model NTXs were built and saw use in airfields, mostly in the Pacific theater.