The History of Motor Graders
Motor graders have traversed quite a long journey since they were invented in the late 19th century. During all these years, they have improved for the better and are now being employed for multiple applications at various jobsites. Today, motor graders are used extensively in construction, road building and maintenance and even at mining sites.
Before diving deep to know about the history of motor graders, first we need to know as to what is a motor grader? Well, also called as a road grader, patrol or maintainer, motor grader is a piece of heavy machinery used for creating smooth, wide, flat surface. Typically, motor graders are used for fine grading, spreading and earthmoving. These days, motor graders are also used for clearing debris and brush, as well as for snow removal. With a variety of attachments, motor graders can actually become very versatile equipment.
A small motor grader within a range of 80-150 horsepower is perfect for jobs that need to be completed in a tight spacing environment, while larger motor graders can be used in broader spaces. Motor graders are broadly classified into two categories based on the structure and arrangement of the frame i.e., Rigid Frame Motor Grader and Articulated Frame Motor Grader. Of the two, the later is the most commonly used version these days.
Tracing the origins of motor graders
1. Horse-drawn graders:
The earliest known graders were drawn by horse or oxen and consisted of simple steel frames fitted with wheels and a fixed-angle blade. This type of grader was invented in 1885 by Joseph D Adams, in Indianapolis and was named as ‘Little Wonder’. It was made using leaning wheel principle with two wooden wheels and a blade set at a fixed angle.
After few years of this development, in 1896, Adams introduced a new kind of motor grader which was a four-wheel and all-steel grade horse-driven motor grader featuring an eight-foot blade and wheels capable of leaning in either direction. This model was called the ‘Road King’.
2. Tractor-drawn graders:
Gradually, by the early 20th century, steam tractors replaced the horses and oxen and were seen pulling the graders. Later, crawler tractors were used to pull the graders.
3. Motorised graders:
It was in 1919, when Russell Grader Manufacturing Company developed the first self-propelled motor grader which took the form of a modified tractor. It was marketed in the year 1920 as the Motor Hi-Way Patrol No. 1, a grader that consisted of a modified Allis-Chalmers tractor. Seeing this, other tractor manufacturers during that time i.e., McCormick Deering, Fordson and the Cleveland Tractor Company also started modifying tractor designs to incorporate built-in graders.
In the year, 1928, the company Caterpillar which specialised in manufacturing tractors bought Russell Grader Manufacturing. Then the company launched Caterpillar Auto Patrol in 1931 which was a dedicated motor grader with a drivetrain and grader designed as a single unit. Unlike earlier models, the Caterpillar Auto Patrol featured rubber tyres rather than crawler tracks. It became the prototype for all subsequent motor graders. Then, various manufacturers emerged on the scene and continued refining and improving on the grader designs.
Blade control advancements in motor graders
Before 1920s, grader blades were controlled by hand cranks, racks and pinions which were primarily operated by wheels in the operator’s station. However, in 1920s, many manufacturers began developing power controls. They introduced mechanical power controls and once the technology was widely available, hydraulic controls came in. It was in 1935, when Adams launched a motor grader with a blade that could extend sideways making it possible to trim banks and shoulders.
The growth of large sized motor graders
After World War II, not only did the demand for motor graders increased but the size of the equipment also increased. This need arose overlooking the potential uses of graders in industries like mining and in highway construction. This large motor grader trend began with the Galion Iron Works Manufacturing Co.’s production of the T-700 model in 1955. This grader set a size record at that time by weighing more than over 40,000 pounds (18,143 kg) with 190 horsepower and including powershift transmission with a torque-converter-drive.
Later in, 1969, another massive motor grader, the double-articulated Autoblade, was introduced by CMI Corporation. This machine was 40 feet (12 m) long, weighed 65,000 pounds (29,484 kg) and contained a power module at both ends and whose cab could rotate 180 degrees in either direction. The same year, RayGo Inc introduced the Giant featuring dual-end power and double-articulation. This machine was 106,000 pounds (48,081 kg). In 1975, Champion Road Machinery Ltd achieved the world size record for its 100-T model which weighed 202,000 pounds (91,626 kg), had a 700 horsepower Cummins engine and a 24-foot (7.3-m) blade.
At present, the world’s largest grader is produced by Caterpillar and is known as the 24H. This machine was introduced in 1996. It weighs 137,000 pounds (62,142 kg) and boasts a 24-foot (7.3-m) moldboard.
On-going innovations in motor graders and present scenario
Since its inception, motor graders have changed drastically and the manufacturers have been continuously refining the equipment for the better. The changes that have happened till now include advances in engine and brake technologies, more precise control and greater operator comfort through the introduction of joystick in place of traditional levers. Also, today motor graders are fitted with the GPS technology and latest engine designs for maximum power and fuel efficiency.
If we talk about some of the prominent indigenous motor grader manufacturer in the country, then Mahindra Construction Equipment (MCE) with its RoadMaster G75 motor grader tops the list. RoadMaster G75 is one of the most affordable and incomparable equipment in its category in the country at the present. The equipment comes with GPRS based remote monitoring system dogosense that keeps a track of your machine with the touch of a finger. Further, its 3000 mm mouldboard comes with an option of having its size reduced by 400 mm. Depending on the requirement, the blade size can be reduced by 200 mm on bot sides. The cutting edge has a lasting life of about 600 hrs on standard operation cycle. In addition, the RoadMaster G75 comes with the option of having additional fitments i.e., the ripper and dozer for added versatility. The ripper is perfect for ripping hard compacted surfaces before grading while dozer helps with spreading.
To sum up...
Over the years, demand for motor graders has increased drastically. As per Off-Highway Research, the motor grader market is expected to grow from 750 units in 2016 to 850 units by 2020. Also, it is estimated that the demand of motor graders will definitely increase by 15-20 per cent in the next 4-5 years. Thus, indeed future of motor graders looks bright.