The Earliest Bulldozers

Ever since we started rearranging the surface of the earth, there has been a need to push piles of dirt and rock and, especially, to push it into holes or over the edge of a bank. It could certainly be done with hand tools, but only with great effort and much time. The difficulty arose with how to do it mechanically.

Horses were great at pulling machinery, and did reasonably well with pull graders to spread material behind them as they walked. But how to use horses to spread material ahead of them?

Its year of invention and the name of the inventor are lost to history, but in the mid- to late-1800s a device was developed to solve this problem. Details vary, but the general design consisted of a long beam with a perpendicular, vertical blade at one end and an axle and teamster’s seat at the other. With horses attached to both sides of the beam, it provided a handy means of using the original form of horsepower to push material in advance of the team. The earliest examples known to this author were built circa 1880, and these primitive “bulldozers” were produced as late as the early 1920s. 

As crawler tractors were introduced into agriculture and logging in the late 1910s, it was only natural that these eminently practical machines should be adapted for construction. Not only were they far superior to stock for pulling wagons and scrapers; over time, their potential use with bulldozers emerged as well. Benjamin Holt reportedly tested a blade on the front of a steam tractor as early as 1902, and experimented with a blade on a crawler tractor in 1916. 

The first successful use of a dozer blade on a crawler tractor is believed to have been an invention by LaPlant-Choate Manufacturing Company in 1920 for use at the City of South Milwaukee garbage dump. The blade could not be lifted or lowered; like the blade on the stock-powered dozers, it simply flipped up and dragged on the ground when backing up. 

As the idea of a tractor-mounted blade evolved, so too did variations on the design. An adjustable angle dozer was developed for situations in which spoil had to be moved to the side; indeed, several manufacturers called angle dozers “trail builders” because of their suitability for cutting roads and trails along cross slopes. Other dozers were designed for specific applications such as land clearing, pushloading scrapers, mine reclamation, and gathering and pushing large volumes of bulk material. As hydraulics improved, multi-positional six-way dozers that could be angled and/or tilted came into widespread use. 

Over the years, the crawler tractor came to be known by the name of its bulldozer attachment, and many models of crawler tractors are designed specifically for dozer service.    

Some historians give credit to an American named Benjamin Holt for inventing the first "bulldozer" in 1904, and originally calling it a "caterpillar" or a crawler tractor. However, this would be misleading.

Benjamin Holt Did Not Build a Bulldozer

Expert Deas Plant from the Gold Coast, Queensland, Australia commented that Benjamin Holt developed an endless chain tread for his steam traction engine at the end of 1904. At around the same time, the Hornsby company of England converted one of its wheeled steam traction engines ​to a tracklayer [crawler] format based on a patent granted to their chief engineer. Neither of these developments was a bulldozer, both were purely and simply track-laying traction engines. However, the Hornsby's version was closer to the bulldozers we know today in that it was steered by controlling power to each track instead of having a tiller wheel out in front of the tracks as Holt's machines did. Hornsby sold their patents to Benjamin Holt around 1913-14.​

First Came the Bulldozer Blade

It is not certain who invented the first bulldozer, however, the bulldozer blade was in use before the invention of any tractor. It consisted of a frame with a blade at the front into which were harnessed two mules. The mules would push the blade into a heap of dirt dumped by a cart and spread the dirt or push it over a bank to fill a hole or gully. The fun part came when you wanted the mules to back up for the next push.

Definition of a Bulldozer

The term bulldozer technically refers only to a shovel-like blade, over the years people have come to associate the term bulldozer to the entire vehicle both blade and crawler tractor combined.

Deas Plant added that "There is also some debate about who first fitted a bulldozer blade to a track-laying tractor, perhaps the La Plante-Choate company, one of the early manufacturers of bulldozer blades."

Again, there are various claimants for the title of first to fit a power control to one of these bulldozer blades with Robert Gilmour Le Tourneau probably being the leading contender.

The Caterpillar Tractor Company

The name caterpillar was coined by a photographer working for Benjamin Holt who was taking photos of one of Holt's track-laying or crawler tractors. Looking at the machine's upside-down image through his camera lens, he commented that the top of the track undulating over its carrier rollers looked like a caterpillar. Benjamin Holt liked the comparison and adopted it as the name for his track-laying system. He was using it for some years before the formation of the Caterpillar Tractor Company.

The Caterpillar Tractor Company was formed by the merger of the Holt company and their major competitor, the C. L. Best Gas Tractor Co., in August 1925.

What Do Bulldozers and Bulls Have in Common?

It appears that the word bulldozer came from the habit of stronger bulls pushing their lesser rivals backward in not-so-serious contests of strength outside of the mating season. These contests take on a more serious note during the mating season.

According to "Bulldozers" written by Sam Sargent and Michael Alves: "Around 1880, the common usage of 'bull-dose' in the United States meant administering a large and efficient dose of any sort of medicine or punishment. If you 'bull-dosed' someone, you gave him a severe whipping or coerced or intimidated him in some other way, such as by holding a gun to his head. In 1886, with a slight variation in spelling, a 'bulldozer' had come to mean both a large-caliber pistol and the person who wielded it. By the late 1800s, 'bulldozing' came to mean using brawny force to push over, or through, any obstacle."