Established in the 1880s, Eimco designed and built underground mining equipment. In a surprising move, it decided to go above ground and enter the track type tractor market. By Richard Campbell.
Eimco (Eastern Iron and Machinery Co), was not a widely known name in the track tractor industry.
The reason being that the period in which they manufactured and offered track tractors and loaders was quite brief, from 1952 through to 1965.
However, the tractors they built were advanced for their day and did not resemble any other contemporary manufacturers’ machines. There was no mistaking an Eimco for anything else.
Eimco’s tractor manufacturing facility was located in Salt Lake City, Utah and it was the sole production centre for track type tractors and loaders.
At the beginning of tractor production, Eimco numbered all of their dozers with odd numbers (103, 105 etc) and the track loader range received even numbers, 106, 136 and so on.
Later, this numbering system was changed so that it was not possible to identify an Eimco machine just by its designator, and one had to do a visual check!
In this article we are having a look solely at their range of bulldozers
As Eimco didn’t manufacture their own engines, they relied on General Motors and Cummins for powerplants, with the majority of their machines being powered by GM.
A unique feature of most Eimco tractors was the use of two transmissions, (usually Allison), driven by a splitter box off the engine’s flywheel.
This allowed both tracks to be powered all the time and did away with the need for large steering clutches and final drives.
The machine could be put into a gradual turn by having one transmission in ‘hi’ range and the opposite side in ‘lo’, or a spot turn could be made by having one side in forward and the other in reverse.
This was a similar arrangement to that used in the Euclid TC-12 (although the TC-12 also used two engines) but the concept actually preceded that of the big Euclid.
Eimco’s first offering into the tractor market was the Model 105, a 15 ton machine powered by a 138 horsepower GM 4-71 diesel, which was introduced in late 1952.
As mentioned previously, visually it was like no other track type tractor.
For starters, the operator sat right up front behind a dash panel that was sloped sharply downwards. He also sat high, with a good view of the work area.
The engine, transmission and cooling system were located behind the operator under a narrow and rakish bonnet. This allowed for a very compact drive train and excellent protection for the radiator.
The entire under chassis was built from a U-shaped tub and was reinforced underneath to protect it from rocks and stumps, ensuring a very strong and rigid structure to mount the drive train.
A cutout halfway along the machine accommodated the equalizer bar and each track was pivoted off its own final drive.
The Model 105 was the longest-lived of all of Eimco’s bulldozers, lasting in production from 1952 through to 1962. However, total production of the Model 105 was only 1279 machines.
The first Model 105 machines offered for sale were typically equipped with a Bucyrus angle blade operated by an IH/Superior double drum cable control unit (PCU).
While coming across an Eimco dozer would be something of a rarity among a contractor’s spread in the 1950s and 1960s, Eimco had a great deal of success supplying the US Military with equipment and it was in this market that the company had its best sales success.
An awful lot of Eimco tractors and dozers were used in the Korean and Vietnam wars where they gained a bit of an unsavoury reputation as ‘mine hunters’, as running over a land mine pretty much a guaranteed trip to the hospital, if you survived the blast, due to the up front position of the operators compartment.
Eimco’s next machine, the Model 103, was introduced in1958 and this was basically a scaled-down version of the Model 105 weighing only 9½ tons.
It was also offered as a front end loader, known as the Model 106.
Powered by a GM 4-53 diesel, the 103 had a top speed of almost 6mph. Manufactured up until 1960, Eimco sold 286 of its 103 model.
Operators felt the machine was a bit underpowered and a tad on the light side so a partial redesign was undertaken resulting in the Model 103B which first appeared in 1961. A GM 6V-71 replaced the GM 4-53 engine and a Cummins NH200 was also available as an option. Operating weight was now 13 tons bare.
Eimco had moderate success with this 03B and sold 850 of them, mostly to the US Government. Today, it is the most likely type you will find in a preserved condtion.
The largest of the Eimco bulldozers was the model 165 which tipped the scales at 17 tons bare and was powered by a GM 6V-71T, GM 8V-71 or a Cummins NH220 diesel. It was introduced the same year as the Model 103B, 1961.
This was the second biggest seller for Eimco, with sales exceeding 1000 units, agains, mostly sold to the US military for various contracts.
A Model 165B was offered from 1964 through 1965 when the type was discontinued.
End of the road
Despite healthy sales to the US Government, commercial retail sales were almost non-existent and there appeared to be quite a bit of customer resistance to Eimco’s machines for whatever reason. Perhaps they were a little too far ahead of their time.
As military contracts could not be relied upon, the decision was made to close down the tractor division and it was shut down for good in 1965. Eimco then returned to its core business of underground mining equipment.
When the USA finally pulled out of Vietnam in 1975, they had a considerable stock of earthmoving equipment that had been used for building and maintaining airbases, bunkers, emplacements and the like. Those Eimco’s that hadn’t been blown up in war zones in Laos, Vietnam, Cambodia and Thailand were returned to the USA and sold as Army Surplus.
Many of these machines had under 1000 hours on the clock and were great buying as budding contractors could pick up earthmoving equipment for a fraction of the cost of a new machine.
Some of these machines have survived and a few are even still in use.
The New Zealand connection
I have never seen an Eimco bulldozer in this country, however their underground mining shovels, known as “muckers” were used on the Tokaanu and Manapouri projects where they were well regarded.
Eimco’s Australian dealer, Tutt-Bryant, sold several Model 103’s and Model 105’s to the Australian Army, but their eventual disposal and fate is unknown.
For the model collector
Regrettably, the author knows of no Eimco models whatsoever in any scale.
Disappointing, as one would make a great conversation piece in a spread of more well known equipment.