Front-end loaders are so commonplace that they blend into the mechanical landscape at construction sites. Most farms, many estates and even some suburban homes are equipped with at least one. This ever-practical tool is designed principally for loading bulk materials and excavation, but it gets used for everything from hoisting engines out of pickup trucks to scraping away sod for a new flowerbed.
Who built the first tractor loader is anybody's guess, but it was likely the result of an enterprising farmer's desire to find an easier way to load manure. Some primitive tractor-mounted loaders used winches to raise and lower the bucket, while others employed more tenuous gear-driven mechanical linkages. Frank G. Hough (pronounced Huff), a young engineer in Chicago, believed in the potential of hydraulics and pioneered a much better way in the early 1920s. With his initial invention, Hough excavated the footings for a material-moving legacy whose contributions included the first production wheel-tractor-mounted front-end loader, first integrated wheel loader, first four-wheel drive loader and the largest mechanically driven loader, among many others.
In the beginning
At age 20, Frank G. Hough (1890-1965) was superintendent for the Field Mining and Milling Co., in Lafayette County, Wis., when he first became interested in applying hydraulics and wheels to movement of bulk materials. This eventually led the young engineer to a position as vice president and general manager of the Blair Mfg. Co. in Chicago, where, in 1922, he sold his first tractor-mounted shovel attachment. This original shovel, mounted on a Fordson farm tractor, was based on an invention whose patent he shared with Russell B. North and Royal R. Miller. The device was called the North hydraulic digger.
At Blair, Hough rapidly developed loaders for McCormick-Deering, Allis-Chalmers, and Case farm and industrial tractors. By the late 1920s the company offered the Blair hydraulic digger alongside bulldozers and backfilling blades that could be fitted to wheeled tractors and track machines.
The Blair hydraulic digger consisted of a vertical mast frame mounted to the front of the tractor, a pair of loader arms that pivoted at the rear of the tractor connected to a bucket up front, and a hydraulic lift mechanism. Essentially, a hydraulic cylinder located between the mast-frame's side rails raised a pair of cable-threaded sheaves that in turn raised the bucket-end of the loader arms, which were attached to the cables' ends. The vertical mast's side rails guided the loader arms, and the cable-sheave arrangement allowed the cylinder's relatively short stroke to be translated into higher lift. It looks like a little rattletrap in comparison with modern loader designs, but it was innovative and quite useful at the time.
Hough purchased Blair Mfg. Co. in 1931, and in 1933 incorporated as the Frank G. Hough Co. Like its predecessor, the newly named company concerned itself with engineering and sales, but not fabrication. Meili-Blumberg of New Holstein, Wis., and others were contracted to manufacture Hough's designs and drop-ship them directly to customers or dealers. In the early 1930s the company's products included tractor-mounted loaders, bulldozers and sweepers.
In 1936, Frank G. Hough Co. released its first heavy-duty loader. The device was a near-perfect match for the Allis-Chalmers Model M crawler, although engineers modified that machine with a lengthened track, beefed up rollers and foot-operated clutch, renaming it the WM in that configuration. This so-called Hough tractor shovel was based on the mast-frame-style loader, but it was heavy enough to withstand the rigors of excavation and was even able to dig basements, a task previously the exclusive province of dipper-stick and dragline diggers.
Hough's tractor shovel was quickly joined by the tractor sweeper-blower, designed to prepare roads for paving, and a pick-up sweeper with integrated sprinkler to clean city streets. In 1938 Hough released a new 0.75-cubic-yard capacity hydraulic shovel designed specifically for International Harvester's TD-35 TracTracTor (crawler). This was Hough's largest capacity shovel at the time.
Throughout those early years, Hough's most vexing production issue was related to the dynamic nature of tractors. Tractor manufacturers constantly changed their designs and regularly added new models, necessitating continuous changes to Hough's loaders. The problem was further exacerbated by some manufacturers' reluctance to provide Hough with detailed drawings of the new models. When customers had a problem, Hough staffers sometimes conducted on-site visits to make adjustments.
Hough's solution was to design his own integrated wheel loader for the specific purpose of material handling, and take ownership of the manufacturing process to boot. In a move arguably ahead of its time, Hough established a complete manufacturing and servicing facility at Libertyville, Ill.
Loaders that pay
The Frank G. Hough Co. moved from Chicago to Libertyville in 1939, and that same year released the world's first and their smallest integrated wheel loader, the Model HS (Hough Small) Payloader. The Model HS had an innovative design with a rear-mounted engine positioned over the drive wheels and the transmission further to the rear for added ballast. The loader utilized Hough's mast-frame design, and the machine proved useful for loading and unloading boxcars, and handling bulk materials in factories and warehouses. In 1941, Hough's Model HL (Hough Large) Payloader was released. This machine was capable of handling about 1 cubic yard of material in a design similar to the HS, although the operator's station was up front directly behind the mast.
World War II cut short the production life of the Model HS, but its memory was never lost as Hough offered a tiny, maneuverable Payloader of some type for the next several decades. From 1942 to 1945, the company developed materiel for the war effort. Hough produced hydraulic gun elevating equipment and built a small, compact and heavy-duty loader for the Case Model SI tractor called the airborne loader, used to build or repair small airstrips after being parachuted in. Hough sweepers mounted on Ford Moto-Tug tractors kept aircraft carriers' decks clear, and were tested for snow and ice removal during at least one War Department activity called Operation Frostbite. The Frank G. Hough Co. received the coveted Army-Navy E award in 1943, and by war's end, three stars were added to it for continued excellence in the production of military equipment.
After the war, Hough began a complete redesign of its Payloader brand of wheel loaders. That effort resulted in the 1947 release of a new 10.5-cubic-foot capacity Model HA (some say it was a replacement for the HS). This Hough loader was especially innovative because a pair of hydraulic cylinders acting directly on the pivoting loader arms replaced the mast frame and offered better control of the bucket's height. The rear-wheel-steered Model HA also located the operator in front, ahead of the engine and over the drive wheels, which afforded unprecedented visibility now that the mast frame was gone. The Model HL also received the new-style loader that year and perhaps most notably, its bucket was now hydraulically controlled.
Hough built the industry's first four-wheel drive loader, the Model HM Payloader, in 1948. This robust tractor had a 1.5-cubic-yard capacity and, as with the other models, the operator was located up in front with the engine out back. The machine was built on a rigid frame and featured rear-wheel power steering, a fully reversing transmission, and speeds up to 16 and 24 mph in forward and reverse, respectively. The HM really provided the basis for all of the larger capacity four-wheel drive front-end loaders from any manufacturer for many years.
Payloader Models HE and HF were introduced in 1949, with 0.5- and 0.75-cubic-yard respective capacities. These machines were similar to the Model HL in that they both were rear-wheel drive and front-wheel steer. These new Payloaders also featured full hydraulic bucket control, and a new curved loader arm design that allowed more tire clearance, especially with the bucket in transport position. The similarly designed 1.25-cubic-yard capacity Model HY Payloader came on line in 1950, along with a factory expansion nearly doubling the size of Hough's Libertyville facility. The 15-cubic-foot capacity Model HAH, a larger capacity version of the Model HA, went into production in 1951 along with a second four-wheel drive Payloader, the Model HR.
By 1950, Hough had introduced the integrated wheel loader in two-wheel and four-wheel drive configurations. Michigan was still four years away from releasing its first production unit, and Caterpillar was a full decade away from that same end. Although he had some minor competition, Hough was in great position to attract a buyer. On Nov. 1, 1952, Hough sold his company to International Harvester for $7.8 million in Harvester stock, which seems a small price to pay for a firm with cutting-edge technology and 1952 sales of $20 million. Payloader was still the leader (nearly the only player) in the front-end loader market, and as a wholly owned subsidiary of IH, Hough continued its tradition of innovation.
In 1955, Hough introduced an improved Payloader line-up, including the HA, HAH, HU, HH and HO. Hough's own drive axle with planetary-gear final reduction (first introduced on the HW) at the hub was now used in the HU, HO and HH models, and a Hough powershift transmission was available in Models HU and HH. By 1956, Hough's Payloader line-up was far and away the most comprehensive in the industry and included four two-wheel drive models and three four-wheel drive models with capacities ranging from 14 cubic feet to 2.5 cubic yards.
The company again redesigned its loader arm geometry in 1958 by moving the pivot locations to either side of the operator's station and employing a pair of bell-cranks, tie-rods and hydraulic cylinders to control the bucket. This bucket linkage, somewhat reminiscent of the letter "Z" when viewed from the side, was named Z-Bar linkage. That innovation was released the following year on a new line-up of four-wheel drive H-Series Payloaders: H-120, H-90, H-70, H-50 and H-30. These machines offered capacities from 1-4 cubic yards on several rear-steer rigid-frame chassis. About a year later, two modifications - moving the loader arm's pivot points ahead of the operator, and employing a single Z-Bar link between them - further improved performance in a design reflected in virtually every production wheel loader built today.
By the mid-1960s, Hough still owned the biggest share of the integrated wheel loader market, but it had stiff competition from Caterpillar, Clark-Michigan, Trojan and others. The operator's station was always located up front on Payloaders, but it wasn't until 1965 that Hough's four-wheel drive machines had an articulated frame.
By the end of the 1960s, International Harvester dissolved Frank G. Hough Co. by reorienting the company as a division of IHC. The move made sense fiscally and it immediately opened the doors for creative cooperation between Hough and IH's Construction Equipment Division and the Industrial Equipment Group of the Farm Equipment Division. As a Harvester division, though, Hough now felt the same squeeze for development funds and top-down control of development direction as most other company divisions at the time. As the division most closely allied with the often-ailing Construction Equipment Division, Hough suffered substantial neglect.
Hardships notwithstanding, IH's Hough Division (and later PayLine Division) was able to continue improving its line of Payloaders until the beginning of the 1980s, when IH sold most of its construction equipment interests to Dresser Industries. Dresser in turn sold them to Komatsu and Komatsu subsequently sold them to Huta Stalowa Wola (HSW), a company owned by the government of Poland. HSW still manufactures several 500-series loaders that trace their ancestry to Hough's original Payloader and markets them under the Dressta brand. Those machines continue to serve on construction sites, in feedlots, material yards and quarries around the globe.
A long-time member of Construction Equipment magazine's Hall of Fame, Frank G. Hough is credited with inventing the first fully integrated wheel loader, and innovating hydraulic bucket control, four-wheel drive for loaders, Z-Bar loader control linkage and hydrostatic transmissions for wheel loaders among many other accomplishments. Hough's influence on the loader market was so profound that his company's influence can be seen today on many different brands. In 2006 at least one wheel loader manufacturer even boasts about Z-Bar technology. Hough Pay-loaders were first equipped with that innovation nearly 50 years ago but it is good to see that Hough's innovations are still alive. FC
Oscar "Hank" Will III is the Editor-in Chief of GRIT magazine. Contact him at firstname.lastname@example.org.