With firm ties to the southern California aircraft industry, the Earthmaster tractor first appeared on the scene in the late 1940s with an association to the Aerco Corp. at Van Owen St., Burbank, CA. Aerco advertised two- and four-wheeled tractors with the name Earthmaster for about a year before the Earthmaster Farm Equipment Co. was formed in 1948 as a division of Adel Precision Products Corp.
Adel was a highly successful aviation contractor during World War II, innovating among other things hydraulic valves and control systems to prevent tail gunners from shooting off the tails of their aircraft. In a 1944 advertisement in Fortune Magazine, Adel claimed its eventual peacetime manufacturing would bring innovative products to home and industry to make work lighter. Certainly with the country’s hunger for post-war agricultural machinery, taking on a line of farm equipment must have seemed quite prudent at the time.
Initially, Earthmaster Farm Equipment’s address was the same as that advertised by Aerco. The company manufactured several different tractors using high-quality components such as Briggs & Stratton or Continental engines and Timken bearings. Different models of walking tractors typically had different engines or drive trains, while different models of the larger four-wheel tractors had different axles, tires and front-end dimensions. For example, the C Series four-wheel tractors included at least five variants such as the general purpose Model C and the high-crop version Model CH. All of the four-wheel tractors had Continental N-62 four-cylinder engines, three-speed transmissions, disc brakes and were available with live hydraulics, belt pulley, rear PTO, wheel weights and several other options.
Through 1949, Earthmaster Farm Equipment continued to offer dozer and scraper blades, belt pulleys, cultivators, sickle-bar mowers, shredders, mounted plows, planters and many other attachments for its tractors from the Burbank, Calif., location. Most traces of the Burbank-based Earthmaster disappeared by the early 1950s, however. According to some enthusiasts, S.L. Allen & Co., makers of Planet Jr. implements, was the first owner of Earthmaster after Adel. S.L. Allen is credited with producing many of the Earthmaster tractor attachments, however, no record exists of any tractors being produced by that Pennsylvania company.
Earthmaster surfaced again in the mid-1950s in North Carolina where a line of four-wheel tractors, virtually identical to those made originally in California, was produced by C.F. Latham & Co. By the end of the 1950s, manufacturing of new Earthmaster machines had ceased, although parts were still available into the 1980s from Latham.
Custom Mfg. Corp
The Custom Mfg. Corp. was formed late in 1944 by several former employees of the Co-Op tractor plant in Shelbyville, Ind. Although its initial effort was aimed at producing war supplies for the United States government, it wasn’t long before the firm began producing tractors for machinery-starved American farmers. The company produced both standard and row-crop models from readily available components. Engines were supplied by Chrysler industrial; heavy-duty, five-speed truck transmissions were sourced from New Process (now New Venture Gear Inc.); and axle makers like Eaton and Timken supplied the final drives. Custom’s initial offering was the 25-hp Model B row crop, and a Wheatland-style Model C shortly followed.
Custom marketed its tractors under the Custom brand through the Diamond T truck network and under many other brands through several different venues. Tractors with names like Rockol, Regal and Regal Custom were all manufactured by Custom for other companies interested in cashing in on the post-war rush for equipment, some of which was also sold in Canada.
The Harry Lowther Co., a forestry- and farm-equipment manufacturer from Joliet, III., bought the Custom Mfg. Co. in the early 1950s and introduced the Chrysler Cyrol fluid-drive system into several tractor models, including both the row crop and Wheatland versions of models E and H. These tractors were sold as Custom and Wards tractors.
After only a couple of years under Lowther’s ownership, the company was in financial difficulties and was sold as the Custom Tractor Mfg. Co. to George Pusch in Hustisford, Wis. Under Pusch’s ownership, and from the new location in Wisconsin, the company managed to produce more powerful 96 and 98 series tractors along with the largely unchanged models E and H. Custom survived in Wisconsin until 1954, when its doors were shut for good.
Still located in Hanover, Pa., the R.H. Sheppard Co. was founded in 1937 as a small manufacturing company whose owner was very interested in diesel engines. Sheppard successfully lead his engine company through the war years and began experimenting with Sheppard diesel engines to re-power existing tractors. One such conversion was an International Harvester Co. Farmall Model M, which lead to the development of Sheppard’s own diesel tractor in 1949.
The initial Sheppard line included one-, two- and three-cylinder tractors called the SD-1, SD-2 and SD-3 models. Marketing materials enticed farmers with claims of economy, simplicity and power. Three- or four-speed heavy-duty transmissions, Timken axles and Ross steering gears made it clear that Sheppard had designed a quality machine. Sheppard supplied a host of implements for its machines. Some were of their own design, while others were built from supplied components.
By 1954, there was enough interest in Sheppard diesel tractors that a pair of industrial tractors was released based on the Model SD-2 and Model SD-3. That same year, a larger four-cylinder farm tractor was released as the Model SD-4, and it included a power-steering unit designed and built by Sheppard. This innovation has proved to be the base for the company’s thriving success to date.
By 1956, it was clear to R.H. Sheppard that the post-war agricultural equipment windfall had run its course, so new tractor manufacturing was shut down. Sheppard’s heavy-duty steering gear business was growing rapidly though, and while it continued to produce diesel engines until 1963, engines were no longer the principal business of the company.
To this day, R.H. Sheppard supplies heavy-duty steering gears and other components to truck and industrial-vehicle manufacturers. – Oscar H. Will III