Wheeled loader developments

The wheeled loader has become a key tool for the quarry sector, whether for loading haul trucks or in-pit crushers and for stocking duties. Mike Woof looks at the development

Highly versatile and mobile, the wheeled loader has become an important machine in the quarrying industry.

The first wheeled loaders were developed in the 1920s and were based on agricultural tractors, with these machines being used mainly on construction sites or for stocking and handling materials. Many of these crudely converted tractors ran on solid tyres and, coupled with the clumsy cable-operated mechanical loader arms, were uncomfortable, unstable and potentially dangerous to operate.

In the 1930s manufacturers began to develop proper wheeled loaders, although these still used mechanical means to lift the loader arms as the hydraulics of the time were unreliable and prone to leaks. One of the first machines designed specifically as a wheeled loader was the American made Hough HS, which appeared in 1939 and this tiny machine was mainly used in construction jobs.

The technological advances made in military equipment during WWII resulted in more reliable hydraulic systems, which appeared on a new generation of wheeled loaders introduced soon after the war ended. As time progressed firms developed larger machines and their versatility and mobility encouraged quarrying firms to introduce them first for rehandling and then for loading purposes.

Hough once again led the field with its petrol driven HM model of 1947 featuring actuation of its loader arms and bucket and having the distinction of being the first wheeled loader with four wheel drive. The Wagner brothers were first to build an articulated wheeled loader with their Scoopmobile Model LD-5 first rolling out of the plant at Portland in Oregon in 1953.

Early wheeled loaders did suffer safety issues though, with a major problem being the location of the pivot arms behind the operator as this impaired visibility and there was a risk of the operator being caught in between the loader arms and the hydraulic rams. Following discussions with the US National Safety Council manufacturers reconfigured their designs and Hough again was amongst the first to introduce a new model with the loader arm pivot point in front of the operator position.

473 Volvo first made a wheeled loader in 1954, with its Munktell business redesigning one of its tractors to drive backwards and with the loader arms positioned on either side of the larger wheels and steering provided by the smaller wheels, now at the rear.

394 Case introduced its first wheeled loader with all-wheel-drive, the W-9, in 1958 and this was followed by the W-10 and W-12 as well as the front-wheel-drive W-5. A feature of the Case loaders, as with many others available from rival firms, was that the cab was mounted on the forward chassis. This provided a good view of the loading operation but provided more vibration and Case later followed the market trend to relocate the cabs to the rear chassis.

395 Caterpillar's first wheeled loader, the 944, was launched in 1959 and was followed one year later by the 922 and 966 models and all of these had loader arms pivoting in front of the operator. Cat's first articulated wheeled loader was the 988 of 1963 and from then on the firm's subsequent additions to the loader range were articulated, although the original 944 and improved 922B with four-wheel-steer remained in the range until 1968.

Many of the early names from the wheeled loader sector, such as 3676 Allis-Chalmers, Clark Equipment Euclid, Michigan or Yale, have long gone from the industry.

But their legacy continues - Hough was merged into International Harvester, which later became Dresser and was finally bought up by 436 Komatsu. Similarly, the business established by the Wagner brothers began to focus on underground mining machines and was acquired by 385 Atlas Copco. The current Atlas Copco Scooptram is a direct descendant of the articulated Scoopmobile LD-5.