THE JEEP - ITS DEVELOPMENT AND PROCUREMENT UNDER THE QUARTERMASTER CORPS, 1940 - 1942

By Herbert R. Rifkind - 1943

Of all the possible peacetime uses to which the jeep type of vehicle might be put after the war, probably the most important commercial application will be in the field of agriculture. The capabilities of the jeep as an all-purpose farm power unit have already been established by a series of tests conducted by the United States Department of Agriculture, April 13-15, 1942, at its Farm Tillage Machinery Laboratory located at Auburn, Alabama. In these tests the jeep proved that it could successfully substitute for a small tractor in many light plowing and harrowing operations and otherwise demonstrated its ability to perform different types of field work. It also acquitted itself well when used as a general utility, farm transportation vehicle. R. M. Merrill, head of the laboratory, directed the experiments, and I. T. Reed and E. D. Gordon, engineers connected with the laboratory, aided in the trials. Interested Department of Agriculture observers of the tests were R. B. Gray, Chief of the Farm Machinery Division, and F. L. Teuton, Chief of the Information Division, both of the Bureau of Agricultural Chemistry and Engineering, Washington, D. C.

Two regulation Army jeeps with standard 4-wheel drive and using 600x16 mud and snow tread tires were employed in the experiments, One was a Willys supplied by that company, the other being a Ford furnished by the Fourth Corps Area Quartermaster. The field tests in which they were tried included pulling practically every implement used in operations necessary to the raising of a crop. Without faltering, the jeeps plowed the field, prepared the seed bed with double disk and tooth harrows, seeded with a grain drill and two row cotton or corm planter, and harvested a crop of rye with a mowing machine.

The first operation consisted of pulling a turning plow cutting a sixteen-inch furrow, through a semi-sandy loam with the implement set to plow about seven or eight inches deep. The jeep accomplished this task without any difficulty, plowing a strip of land about fifty feet wide and a quarter of a mile long, at a speed of from three and one half to four miles per hour. According to observers, the power exhibited by the jeep in this operation was equivalent to that of a three or four horse team, while the rate at which it pulled the plow was twice as fast as that of the team.

After the field had been plowed, it was gone over with a double disk harrow pulled by the jeep, an operation that was said to require even more power since this time the jeep was working in soft plowed ground. With the plowed land now thoroughly disked, a tooth harrow of two sections was employed until the soil was completely pulverized. A grain drill was then hooked to the jeep and a stimulated seeding operation was gone through, following which another type of seeding machine, the two row cotton or corn planter, was operated.

Next came the most difficult test of all - pulling a double turning or gang plow, an implement carrying two plows each cutting a fourteen-inch furrow. With the plows set at approximately the same eight-inch depth, the jeep went down the field, apparently at the sane rate of speed as previously, simultaneously cutting two fourteen inch furrows totalling twenty-eight inches of turned soil.

The above tests were made in a field about two miles east of Tuskegee, Alabama. When removed to rolling fields near the dairy barns of the Alabama Polytechnic Institute at Auburn, the jeep continued its demonstration as a farm power plant by pulling a lime spreader and manure spreader over and around terrace contours. The three-day experiment in farming operations then was concluded by the jeep pulling a mower to harvest a field of rye. To further demonstrate the versatility of the jeep as a handy, all-purpose farm vehicle, sacks of feed and milk cans were loaded on it to show how the farmer might use the jeep to haul his milk and other produce to the market.

The official press release on the results of these tests, issued by the Department of Agriculture, disclosed that while the jeep could be considered “highly useful” as supplemental power for such farm operations, it was not suitable for the cultivation of row crops. In the opinion of R. B. Gray, one of the Department’s experts who witnessed the jeep tryouts, the vehicle was both too low and too narrow for the usual row-crop cultivation jobs. It was also thought that better performance at farm work could be had from the jeep if it were furnished a slightly lower low-gear ratio and a lower hitch for plowing.

In comparison with the usual one or two-plow small farm tractors, the jeep showed a little faster plowing speed, but its drawbar horsepower proved to be from one to three less, its pull was about two-thirds, and its horsepower hours per gallon about a third less. When tested on the dynamometer at the Tillage Laboratory the jeep pulled 1,300 pounds with almost no wheel slippage. Additional engineering data compiled .by Department of Agriculture engineers, revealed that the jeep made the following record when pulling one sixteen-inch plow cutting seven inches deep in bottom cotton land:

Drawbar horsepower …………..……….… 8.51
Drawbar pull…………………… …………862 lbs.
Speed………………………………………3.7 m.p.h.
Fuel (gasoline) per hour………………………1.35 gal.
Drawbar horsepower hours per gal……………6.31
Hours per acre ……………………… ………..1.72