Today motor graders are used extensively in construction, road maintenance, mining, agriculture and more. These useful machines have come a long way since they were invented in the late 19th Century, and it’s hard to imagine how we’d manage without them. Here we consider their history.
Horse-drawn graders
The earliest graders were drawn by horse or oxen, and consisted of simple steel frames fitted with wheels and a fixed-angle blade.
The first documented grader of this type was invented in 1885 by Joseph D. Adams, in Indianapolis. Named the “Little Wonder”, it made use of the leaning wheel principle, with two wooden wheels that could be angled to the side.
In the early 1890s, Adams formed his own company, which manufactured a range of construction machinery, including graders. In 1896, the company released a four-wheel, horse-drawn motor grader, featuring an 8-foot blade and four wheels rather than two. This model was dubbed the “Road King.”
Tractor-drawn graders
By the early 20th Century, steam tractors, which were powered by steam engines, had started to replace horses and oxen, and these were successfully used to pull graders.
After World War I, internal combustion engines became more widely available. The engines were cheaper, faster and lighter than steam engines, and were used to power crawler tractors – which in turn could pull equipment like ploughs or graders.
The first motorised graders
The first self-propelled motor graders took the form of modified tractors. In 1920, the Russell Grader Manufacturing Company began marketing the “Motor Hi-Way Patrol No. 1”, a grader that consisted of a modified Allis-Chalmers tractor.
Other tractor manufacturers, among them McCormick Deering, Fordson and the Cleveland Tractor Company, followed suit, modifying tractor designs to incorporate built-in graders. In 1928, J.D. Adams – famous for inventing the first leaning-wheel grader design – released the popular model known as the “No. 10.”
Also in 1928, the Caterpillar company, which specialised in manufacturing tractors, bought Russell Grader Manufacturing.
The dawn of the Caterpillar era
Caterpillar secured its place in the motor grader industry in 1931, with its “Caterpillar Auto Patrol” model (later renamed the “No. 9 Auto Patrol”). Rather than just a grader fitted to a tractor, this was a dedicated motor grader, with a drivetrain and grader designed as a single unit. The engine was rear-mounted to provide superior balance and visibility.
Unlike earlier models, the Caterpillar Auto Patrol also featured rubber tyres rather than crawler tracks. It became the prototype for all subsequent motor graders.
Caterpillar and other manufacturers continued refining and improving on their grader designs. They also introduced mechanical power controls and, once the technology was widely available, hydraulic controls.
In 1935, J.D. Adams launched a motor grader with a blade that could extend sideways, making it possible to trim banks and shoulders. Three years later, Caterpillar introduced a diesel-powered motor grader, the incredibly long-running “No. 12 Auto Patrol.”
Steady growth in grader demand and size
After World War II, demand for motor graders continued to grow – as did the size of the machines themselves. As the potential uses of graders in industries like mining were realised and a boom occurred in the construction of super highways, the need arose for much bigger graders than in the past.
In the 1960s, Caterpillar launched the “No 16 Motor Grader”, the first of its really large graders, weighing 21,092 kilograms and with a blade measuring 4.3 metres. A decade later, this model was replaced with the 16G, featuring hydraulic controls, an articulating body and a 4.9 metre blade.
1995 saw the launch of the Caterpillar H series of turbocharged graders, including the first all-wheel drive machines. The next year, the company introduced its largest grader to date, the 24H. This giant measures over 16 metres from end to end and weighs in at 61,995 kilograms.
On-going innovation
Caterpillar and other manufacturers have continued refining their motor grader models through the years. This has involved incorporating advances in engine and brake technologies, along with changes designed to offer more precise control and greater operator comfort. For example, the introduction of a joystick in place of traditional levers made motor graders easier to operate.
Today motor graders may be fitted with GPS technology and use the latest engine designs, for maximum power and fuel efficiency.
For all the benefits of a modern motor grader at a fraction of the new price, contact KH Plant for information about its professionally rebuilt Caterpillar 140G, 140H and 140K motor graders.
