![]() ![]() A more recent innovation is the outfitting of bulldozers with GPS technology, such as manufactured by Topcon Positioning Systems, Inc., Trimble Inc., or Mikrofyn [for precise grade control and (potentially) "stakeless" construction. As an option, bulldozers can be equipped with rear ripper claw(s) to loosen rocky soils or to break up pavement (roads). Important improvements include more powerful engines, more reliable drive trains, better tracks, raised cabins, and hydraulic (instead of early models' cable operated) arms that enable more precise manipulation of the blade and automated controls. Firms like Caterpillar, Allis Chalmers, Cletrac, Komatsu, Fiat-Allis, John Deere, International Harvester, Case, Liebherr, and Terex manufactured large tracked-type earthmoving machines.īulldozers grew more sophisticated as time passed. Over the years, bulldozers got bigger and more powerful in response to the demand for equipment suited for ever larger earthworks. These attachments, home built or by small equipment manufacturers of attachments for wheeled and crawler tractors and trucks, appeared by 1929, widespread acceptance of the bull-grader does not seem to appear before the mid-1930s, and the addition of powered down force made them the preferred excavation machine for large and small contractors alike by the 1940s, by which time the term "bulldozer" referred to the entire machine and not just the attachment. ![]() In some early models the driver sat on top in the open without a cabin. Several specialized blades have been developed: for high volume loads such as coal, rakes to remove only larger boulders, or blades with razor sharp edges to cut tree stumps. The blade peels layers of soil and pushes it forward as the tractor advances. This metal plate (it got its curved shape later) is called a " blade". To dig canals, raise earth dams, and do other earthmoving jobs, these tractors were equipped with a large thick metal plate in front. ![]() LeTourneau.)īy the 1920s, tracked vehicles became common, particularly the Caterpillar 60. (See page 140 of 'Mover Of Men And Mountains' by R. To solve this probelem, he fitted a blade to the front of a Best tractor - in those days probably a Best Sixty crawler - added an electric winch to lift the blade and proceeded to push the fill material into the gullies easier than anyone had ever done it before. He had tractor-drawn scrapers bringing the fill material to these gullys but they could not get it much closer than about thirty feet from the edge, let alone get it over the edge into the gully where it needed to be. He was faced with fillng a lot of gullys and arroyos in the process. LeToruneau had a contract to build a road between Oakland and Stockton in California, through Crow Canyon and across the Dublin Mountians. A replica is on display at the city park in Morrowville, Kansas where the two built the first bulldozer. Earl McLeod made the first designs for a bulldozer. In 1923, a young farmer named James Cummings and a draftsman named J. How-wevver, backing the whole issue up or getting it turned for another push around was a whole 'nuther' ball game, especially since the blade could not be lifted. Pushing forward wasn't too bad and the set-up could push a cubic yard or so of material over the edge each time. The history of the 'dozer blade really goes back the late 19th century when some enterprising souls began hitching pairs of horse or mules into a device somewhat resembling a dozer blade to push fill imported by carts into gullys and arroyos. Their versatility in soft ground for logging and road building led directly to their becoming the armoured tank in World War I. The first bulldozers were adapted from Holt, Best, Allis-Chalmers, Cletrac and other makes of farm crawler tractors that were used to plough fields and do other farming work. ![]()
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