The Linn tractor is a heavy duty civilian half-track or crawler tractor invented by Holman Harry Linn (born Holman Harry Flannery). Approximately 2,500 units were built in Morris, New York, USA from 1916 to 1952.
Linn was a native of Maine and in his quest for a better machine to travel rural roads with his dog and pony show equipment gave up on a six-wheel-drive design by 1907 to have Alvin Lombard, of Waterville, build a machine using the tracks off a Lombard Steam Log Hauler, and underslung gasoline engine and wheels on front. It was equipped with a ship-style cabin with living quarters and able to pull a string of wagons behind as well as supply electric lights for his circus. By 1909 this was replaced because of size with a single rear-tracked machine with standard wheeled front axle; however as Linn had become employed as a salesman, demonstrator and mechanic for Lombard a patent dispute erupted and Linn left Maine with his show.
Linn's tractors were clearly inspired by Lombard's, but Lombard preferred a rigid track whereas Linn used flexible track. Since neither inventor had patented the overall concept, just the track system, there was no copyright infringement to prevent Linn from continuing to build his version of the tractors. [1]
By 1916 Linn had developed an even smaller, more stable gasoline-powered half-track with an improved flexible traction system, independent of each other, with a central triangle-shaped rocker using two tear-dropped runner blocks suspended by axles, then surrounded by an independent roller chain to disperse the load through these rollers, patented in 1918. The feature being with constant ground following traction, and steering accomplished by front wheels (or sled in winter); full power was supplied to both tracks all the time and transmitted to the ground so there was no loss of tractive effort when turning. Lombard and most other crawlers used a rigid bed inside the tracks which would be lifted off the ground at times, and track-steer crawlers reduce power through clutch or brake action to their tracks to turn, losing additional tractive effort. With its payload carrying ability, the Linn did not require trailers or wagons to move a load, something which off-road terrain does not always permit, and no dead weight or ballast was needed for traction, as simply more payload could be added. [2]
Linn tractors were used to haul freight beyond the ends of the rail lines on some Canadian power projects. [3] When the concept of rural snow plowing became accepted around 1920, Linn was one of the pioneers, with a v-plow and adjusting leveling wing design that was unmatched until better pneumatic tires, four-wheel-drive trucks and better highways appeared in the mid-1930s to plow highways on a more frequent basis. To combat this a new concept of a single machine able to switch from truck to tractor with the push of a lever appeared in 1938, known as the C5 or later trademarked term "CATRUK", but management and war priorities limited its development and it was abandoned after World War II. This machine was built in a cab-over configuration, front wheel drive, and a hydraulically lowered dual-wheeled tag-axle that would push the tracks up off the ground. "HAFTRAK" is another Linn trademark.
In the 15 February, 1920 issue of Motor West, Linn tractors as being used by B.H. Baird described them as being powered by a 45 hp Continental Motors Company Red Seal engine connected to a four speed model 60 Brown-Lipe-Chapin transmission & differential, with the normal load being 16 tons over an 8% grade and a maximum speed of 6 mph. [4]
Continuous track or tracked treads are a system of vehicle propulsion used in tracked vehicles, running on a continuous band of treads or track plates driven by two or more wheels. The large surface area of the tracks distributes the weight of the vehicle better than steel or rubber tyres on an equivalent vehicle, enabling continuous tracked vehicles to traverse soft ground with less likelihood of becoming stuck due to sinking.
A tractor is an engineering vehicle specifically designed to deliver a high tractive effort at slow speeds, for the purposes of hauling a trailer or machinery such as that used in agriculture, mining or construction. Most commonly, the term is used to describe a farm vehicle that provides the power and traction to mechanize agricultural tasks, especially tillage, and now many more. Agricultural implements may be towed behind or mounted on the tractor, and the tractor may also provide a source of power if the implement is mechanised.
A loader is a heavy equipment machine used in construction to move or load materials such as soil, rock, sand, demolition debris, etc. into or onto another type of machinery.
Heavy equipment, heavy machinery, earthmovers, construction vehicles, or construction equipment, refers to heavy-duty vehicles specially designed to execute construction tasks, most frequently involving earthwork operations or other large construction tasks. Heavy equipment usually comprises five equipment systems: the implement, traction, structure, power train, and control/information.
A half-track is a civilian or military vehicle with regular wheels at the front for steering and continuous tracks at the back to propel the vehicle and carry most of the load. The purpose of this combination is to produce a vehicle with the cross-country capabilities of a tank and the handling of a wheeled vehicle.
Under the Whyte notation for the classification of steam locomotives, 4-2-0 represents the wheel arrangement of four leading wheels on two axles, two powered driving wheels on one axle and no trailing wheels. This type of locomotive is often called a Jervis type, the name of the original designer.
A dump truck, known also as a dumping truck, dump trailer, dumper trailer, dump lorry or dumper lorry or a dumper for short, is used for transporting materials for construction as well as coal. A typical dump truck is equipped with an open-box bed, which is hinged at the rear and equipped with hydraulic rams to lift the front, allowing the material in the bed to be deposited ("dumped") on the ground behind the truck at the site of delivery. In the UK, Australia, South Africa and India the term applies to off-road construction plants only and the road vehicle is known as a tip lorry, tipper lorry, tipper truck, tip truck, tip trailer or tipper trailer or simply a tipper.
A snowplow is a device intended for mounting on a vehicle, used for removing snow and ice from outdoor surfaces, typically those serving transportation purposes. Although this term is often used to refer to vehicles mounting such devices, more accurately they are known as winter service vehicles, especially in areas that regularly receive large amounts of snow every year, or in specific environments such as airfields. In other cases, pickup trucks and front end loaders are outfitted with attachments to fulfill this purpose. Some regions that do not frequently see snow may use graders to remove compacted snow and ice off the streets. Snowplows can also be mounted on rail cars or locomotives to clear railway tracks.
Scammell Lorries Limited was a British manufacturer of trucks, particularly specialist and military off-highway vehicles, between 1921 and 1988. From 1955 Scammell was part of Leyland Motors.
Six-wheel drive is an all-wheel drive drivetrain configuration of three axles with at least two wheels on each axle capable of being driven simultaneously by the vehicle's engine. Unlike four-wheel drive drivetrains, the configuration is largely confined to heavy-duty off-road and military vehicles, such as all-terrain vehicles, armored vehicles, and prime movers.
Truck and tractor pulling, also known as power pulling, is a form of a motorsport competition in which antique or modified tractors pull a heavy drag or sled along an 11-meter-wide (35 ft), 100-meter-long (330 ft) track, with the winner being the tractor that pulls the drag the farthest. Tractor pulling is popular in certain areas of the United States, Mexico, Canada, Europe, Australia, Brazil, South Africa, Vietnam, India and New Zealand. The sport is known as the world's most powerful motorsport, due to the multi-engined modified tractor pullers.
A dolly is an unpowered vehicle designed for connection to a tractor unit, truck or prime mover vehicle with strong traction power.
A tractor unit, also known as a truck unit, lorry unit, power unit, prime mover, ten-wheeler, semi-tractor, semi-truck, semi-lorry, tractor cab, truck cab, lorry cab, big rig tractor, big rig truck or big rig lorry or simply a tractor, truck, lorry, semi, big rig or rig, is a characteristically heavy-duty towing engine that provides motive power for hauling a towed or trailered load. These fall into two categories: heavy- and medium-duty military and commercial rear-wheel-drive semi-tractors used for hauling semi-trailers, and very heavy-duty typically off-road-capable, often 6×6, military and commercial tractor units, including ballast tractors.
The Avery Company, founded by Robert Hanneman Avery, was an American farm tractor manufacturer famed for its undermounted engine which resembled a railroad engine more than a conventional farm steam engine. Avery founded the farm implement business after the Civil War. His company built a large line of products, including steam engines, beginning in 1891. The company started with a return flue design and later adapted the undermount style, including a bulldog design on the smokebox door. Their design was well received by farmers in central Illinois. They expanded their market nationwide and overseas until the 1920s, when they failed to innovate and the company faltered. They manufactured trucks for a period of time, and then automobiles. until they finally succumbed to an agricultural crisis and the Depression.
A semi-trailer is a trailer without a front axle. The combination of a semi-trailer and a tractor truck is called a semi-trailer truck.
An articulated hauler, articulated dump truck (ADT), or sometimes a dump hauler, is a very large heavy-duty type of dump truck used to transport loads over rough terrain, and occasionally on public roads. The vehicle usually has all-wheel drive and consists of two basic units: the front section, generally called the tractor, and the rear section that contains the dump body, called the hauler or trailer section. Steering is made by pivoting the front in relation to the back by hydraulic rams. This way, all wheels follow the same path, making it an excellent off-road vehicle.
A tank transporter is a combination of a heavy tractor unit or a ballast tractor and a mating full trailer, hydraulic modular trailer or semi-trailer, used for transporting tanks and other armoured fighting vehicles. Some also function as tank recovery vehicles, the tractors of which may be armoured for protection in combat conditions.
Roths Industries, Inc. (1945–1960) was a manufacturer of small garden tractors and other agricultural equipment founded by Herbert C. Roths in Alma, Michigan. The company manufactured Garden King Walking Tractors, BesRo Riding Tractors, and Till Ro Stalk Cutters.
The Holt Manufacturing Company began with the 1883 founding of Stockton Wheel Service in Stockton, California, United States. Benjamin Holt, later credited with patenting the first workable crawler ("caterpillar") tractor design, incorporated the Holt Manufacturing Company in 1892. Holt Manufacturing Company was the first company to successfully manufacture a continuous track tractor By the early 20th century, Holt Manufacturing Company was the leading manufacturer of combine harvesters in the US, and the leading California-based manufacturer of steam traction engines.
ZT 300 is a series of 20 kN agricultural tractors, produced from 1 September 1967 to 1984 by the VEB Traktorenwerk Schönebeck. It succeeded the RS14 Famulus series, and unlike the Famulus, the ZT 300 series was sold under the brand name Fortschritt ("Progress"). ZT 300 refers both to the initial ZT 300 model, and the ZT 300 series. In total, 72,382 units of the ZT 300 series were made. The model with the highest production figure was the ZT 303, which was introduced in 1972. It features an automatic all-wheel-drive system; in the early 1980s, it cost 81,000 Mark. Starting in 1983, the ZT 300 series was succeeded by the ZT 320.