Track Mode also improves cornering by applying brake and motor torque at the same time to produce an increase in tractive force while cornering.
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The tractive force was transmitted from the drive-axles to the bogies. From there the force was carried over to the bogie-mounted towing hook and the buffers. In between the bogies were connected with a spring-loaded coupling similar to the tender coupling at steam locomotives. The locomotive body was not engaged in the transmission of tractive force.
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The tractive force was transmitted from the drive-axles to the bogies. From there the force was carried over to the bogie-mounted towing hook and the buffers. In between the bogies were connected with a so-called tender coupling, which consists of one main rod and two auxiliary rods. The locomotive body was not engaged in the transmission of tractive force.
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As used in mechanical engineering, the term tractive force can either refer to the total traction a vehicle exerts on a surface, or the amount of the total traction that is parallel to the direction of motion.SAE J2047, Tire Performance Technology, dated February 1998. In railway engineering, the term tractive effort is often used synonymously with tractive force to describe the pulling or pushing capability of a locomotive. In automotive engineering, the terms are distinctive: tractive effort is generally higher than tractive force by the amount of rolling resistance present, and both terms are higher than the amount of drawbar pull by the total resistance present (including air resistance and grade).
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The tractive force was transmitted from the drive-axles to the frame. From there the force was carried over to the towing hook and the buffers.
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Traction can be defined as: In vehicle dynamics, tractive force is closely related to the terms tractive effort and drawbar pull, though all three terms have different definitions.
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Traction, or tractive force, is the force used to generate motion between a body and a tangential surface, through the use of dry friction, though the use of shear force of the surface is also commonly used. Traction can also refer to the maximum tractive force between a body and a surface, as limited by available friction; when this is the case, traction is often expressed as the ratio of the maximum tractive force to the normal force and is termed the coefficient of traction (similar to coefficient of friction). Is is the force which makes an object move over the surface by overcoming all the resisting forces like friction, normal loads(load acting on the tiers in negative 'Z' axis), air resistance, rolling resistance, etc.
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They are usually armed with machine guns and grenade launchers and usually tracked to provide enough tractive force to push blades and rakes. Some examples are the U.S. M113 APC, IDF Puma, Nagmachon, Husky, and U.S. M1132 ESV (a Stryker variant).
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Baldwin also produced their most powerful steam engines in history, the 2-8-8-4 "Yellowstone" for the Duluth, Missabe and Iron Range Railway. The Yellowstone could put down over of Tractive force. They routinely hauled 180 car trains weighing over .
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The tractive force was transmitted from the drive axles to the bogies. From there the force was carried to the bogie mounted towing hook and the buffers. The bogies were connected together with a so-called short coupling. The locomotive body did not carry any tractive forces.
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A variety of calculations and formulas were applied, but in general railways used dynamometer cars to measure tractive force at speed in actual road testing. British railway companies have been reluctant to disclose figures for drawbar horsepower and have usually relied on continuous tractive effort instead.
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Agricultural equipment is hauled by a tractor mounted drawbar. Specialist agricultural tools such as ploughs are attached to specialist drawbars which have functions in addition to transmitting tractive force. This was partly made redundant with Ferguson’s development of the 3 point linkage in his famous TE20.
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The electric current needed for this was generated by its own engine and a ca. 3 HP dynamo. The magnetic force was sufficient, despite the short length for which the chain was wrapped around the drum, on a trial with an old, chain to generate a tractive force of around .
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Ty2 class locomotives during start-up developed a theoretical tractive force of about . Examples with good quality coal could pull trains weighing at or at In mountainous areas, on grades of 20‰ (1 in 50), they could pull at ; or at the same speed on 25‰ (1 in 40) grades.
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From 1954 to 1972 the plant also produced a wheel-type row-crop tractor with a tractive force of 0.6 tons-force. In 1962 the T-74 ploughing tractor went into production. The plant produced its millionth tractor in 1967. During the ninth five-year plan (1971–75) the T-150K was introduced.
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This increased the turn radius by up to 25%, whereby the 5% elastic limit of the chain was reached. The transfer of tractive force from the drums to the chain was only achieved by friction. If frost or ice built up, the chain could slip. In such events, hot water was poured over the drums.
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In 1903 another 5 units were added to the order. These locomotives were built by the North British Locomotive Company, into which Sharp Stewart and Company was included. They were numbered 404-408. In 1921 the locomotives were renumbered in NS 1610-1659. These last units had a higher steam pressure and a larger tractive force of 5030 kg.
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The Inyo, a 4-4-0 "American" type steam locomotive, was built by the Baldwin Locomotive Works in 1875, and pulled both passenger and freight trains. The Inyo weighs . Its driving wheels deliver of tractive force. In 1877 it was fitted with air brakes, and in 1910 it was converted to burn oil rather than wood.
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The published tractive force value for any vehicle may be theoretical--that is, calculated from known or implied mechanical properties--or obtained via testing under controlled conditions. The discussion herein covers the term's usage in mechanical applications in which the final stage of the power transmission system is one or more wheels in frictional contact with a roadway or railroad track.
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In order to start a train and accelerate it to a given speed, the locomotive(s) must develop sufficient tractive force to overcome the train's drag (resistance to motion), which is a combination of inertia, axle bearing friction, the friction of the wheels on the rails (which is substantially greater on curved track than on tangent track), and the force of gravity if on a grade. Once in motion, the train will develop additional drag as it accelerates due to aerodynamic forces, which increase with the square of the speed. Drag may also be produced at speed due to truck (bogie) hunting, which will increase the rolling friction between wheels and rails. If acceleration continues, the train will eventually attain a speed at which the available tractive force of the locomotive(s) will exactly offset the total drag, causing acceleration to cease.
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Eventually, depending on the requirements of the train's schedule, the engine driver will have moved the throttle to the position of maximum power and will maintain it there until the train has accelerated to the desired speed. The propulsion system is designed to produce maximum traction motor torque at start-up, which explains why modern locomotives are capable of starting trains weighing in excess of 15,000 tons, even on ascending grades. Current technology allows a locomotive to develop as much as 30% of its loaded driver weight in tractive force, amounting to of tractive force for a large, six-axle freight (goods) unit. In fact, a consist of such units can produce more than enough drawbar pull at start-up to damage or derail cars (if on a curve) or break couplers (the latter being referred to in North American railroad slang as "jerking a lung").
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Therefore, he designed the locomotive to create airflow that lifted exhaust smoke away from the locomotive. He had expected no practical effect on reducing air resistance completely, therefore he never tried to test fuel consumption or tractive force of the converted locomotive. The Japanese government planned to use this one converted streamline locomotive on the passenger express route between Osaka and Nagoya. The converted locomotive gained much popularity from the public.
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Some vehicles were fitted with speedometers, an invention of Moses Ricardo. As well as a brake, the driver had a by-pass valve which admitted air to the partially exhausted traction tube ahead of the piston, reducing the tractive force exerted. This seems to have been used on the 1 in 50 descent from the flyover. The lever and valve arrangement are shown in a diagram in Samuda's Treatise.
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In the 1970s, the haulage system was replaced by a three blade abt system which was installed by the Japanese firm Marubeni. The locomotives for this changeover had been constructed by Hitachi. New locomotives (7) have been orderer in 2010 to the Swiss manufacturer Stadler Rail. The rack-and-pinion locomotives are supposed the most powerful ever built, with over 5000 kW of power they develop 760 kN of tractive force.
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All electrical components are placed in predefined locations on either side of a central aisle connecting the two cabins with each mounting position being reserved for a single type of equipment. The bogies transmit tractive force through a central pivot. The traction motors are flexibly supported by the bogie frame, and are connected to the wheelset mounted reduction gears by a multiple disc coupling. A full hollow shaft (folded cardan) drive system is also optional.
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With the Garratt's superiority established, no further Mallet locomotives were ordered by the SAR. During the remaining years of the South African steam traction era, whenever the use of an articulated locomotive was desirable for flexibility, reduced axle loading and high tractive force, the Garratt type was chosen. Two derivative designs, the Modified Fairlie and Union Garratt, would be tried but would both prove to be less successful than the purebred Garratt.
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In 1926 Kitson and Company, Leeds, built an experimental example for the London and North Eastern Railway, using as their model the Still engine already in use for stationary and marine applications. It was on trial until 1934, but then scrapped. It was designed because a steam engine offered a high starting torque—a tractive force of was available—while a diesel engine offered a high fuel efficiency and it was considered desirable to combine the two.
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MLW model S-3 produced in 1957 for the CPR adhering to designs by ALCO. A diesel–electric locomotive's power output is independent of road speed, as long as the unit's generator current and voltage limits are not exceeded. Therefore, the unit's ability to develop tractive effort (also referred to as drawbar pull or tractive force, which is what actually propels the train) will tend to inversely vary with speed within these limits. (See power curve below).
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Flat spot The loss of friction between wheels and rail results in loss of tractive force — the wheels begin to spin, and in some instances the train is unable to move. In braking, substantial loss of friction results in reduced braking force. Braking distances are considerably longer, and in extreme cases the wheels may even lock up, causing the train to slide. Modern locomotives and multiple units are equipped with Wheel slide protection to counter slippery rail conditions.
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The Union Railroad was unique given that it was basically a switching railroad and yet its loads were incredibly heavy made up of either; ore, coke, coal, slag or steel. This unique combination in addition to the steep grades around Pittsburgh demanded some special tractive force. In 1898 the largest locomotive of the time was built for the Union Railroad. This 2-8-0 had more weight on its drivers (208,000 pounds) than any built up to that time.
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Russian 2TE10U Diesel-electric locomotive Traditionally, trains are pulled using a locomotive. This involves one or more powered vehicles being located at the front of the train, providing sufficient tractive force to haul the weight of the full train. This arrangement remains dominant for freight trains and is often used for passenger trains. A push–pull train has the end passenger car equipped with a driver's cab so that the engine driver can remotely control the locomotive.
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Whyte classification is indirectly connected to locomotive performance. Given adequate proportions of the rest of the locomotive, power output is determined by the size of the fire, and for a bituminous coal-fuelled locomotive, this is determined by the grate area. Modern non-compound locomotives are typically able to produce about 40 drawbar horsepower per square foot of grate. Tractive force, as noted earlier, is largely determined by the boiler pressure, the cylinder proportions and the size of the driving wheels.
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After 1931 Allis-Chalmers was the licensee for U.S. sales of European products of Brown, Boveri & Cie. In 1932, Allis-Chalmers collaborated with Firestone to introduce pneumatic rubber tires to tractors.. The innovation quickly spread industry-wide, as (to many farmers' surprise) it improved tractive force and fuel economy in the range of 10% to 20%. Within only 5 years, pneumatic rubber tires had displaced cleated steel wheels across roughly half of all tractors sold industry-wide. Cleated steel remained optional equipment into the 1940s.
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The scheme did not produce a more powerful locomotive; the maximum practical tractive force was governed by the weight on the drivers, and this did not change. The advantage was efficiency: the compounding reduced the steam required for the same performance. According to Baldwin's standard sizing tables, the high-pressure cylinder on the compound was about 70% the diameter of the single cylinder of the conventional engine; therefore, steam consumption for the same stroke and degree of cutoff was about half that of the conventional engine.Catalogue, p.
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Unfortunately the soviet industry could not provide an electric heating feature, therefore the engines were restricted to freight trains for which their gearing was too high. Subsequently, the 'DR Class 131 with a reduced top speed of (and thus a higher tractive force) was delivered for freight services. When in 1972 an electric heating system was available, two prototypes were constructed. Due to poor track conditions in GDR the top speed was limited to , and so the DR Class 132s top speed was reduced to that.
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Under the guidance of L.S. Smart, who had succeeded P.A. Hyde as Chief Locomotive Superintendent of the CSAR in 1905, the CSAR carried out certain modifications to their Kitson-Meyer locomotive in 1906. Since it was impractical to increase the size of the boiler to suit the engines, the diameter of the cylinders was reduced to bring them within the range of the boiler’s steam generating capacity. While this reduced the locomotive’s tractive force, it did result in making the Kitson-Meyer a reasonably good performer.
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The Saxonia was built by Johann Andreas Schubert. Schubert had been inspired by the English-built locomotive, Comet, procured for the LDE, and he analysed and improved on what he saw. He used the same dimensions but, unlike Comet, two coupled axles were driven, therefore providing increased tractive force, and a carrying axle was added at the back to improve ride qualities. The development and construction of the locomotive was carried out in the Maschinenbauanstalt Übigau at Dresden, an engineering works that had been founded on 1 January 1837.
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An experienced engine driver will be able to recognize an incipient stall and will gradually advance the throttle as required to maintain the pace of acceleration. As the throttle is moved to higher power notches, the fuel rate to the prime mover will increase, resulting in a corresponding increase in RPM and horsepower output. At the same time, main generator field excitation will be proportionally increased to absorb the higher power. This will translate into increased electrical output to the traction motors, with a corresponding increase in tractive force.
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The locomotive has one conductor's cabin on each end, connected by an internal corridor. Its total weight is 120 tonnes with a maximum weight per axle of 20 tonnes. The four stroke 16V 4000R43 engine is manufactured by MTU Friedrichshafen and generates 2200 kW at 1800 RPM.MTU engines powering Chinese-built locomotives in Argentina - MTU, 03 July, 2013Apuntes sobre el material rodante chino - Entrevias, 17 December 2013 The locomotives are divided into two sub-models, the CKD8G and the CKD8H with the latter having a higher maximum speed and tractive force.
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Cantilevering the weight of the firebox and the locomotive crew behind the driving axle placed more weight on the driving axle without substantially reducing the weight on the leading truck. However, Norris's design led to a shorter wheelbase, which tended to offset any gains in tractive force on the driving axle by reducing the locomotive's overall stability. A number of Norris locomotives were imported into England for use on the Birmingham and Bristol Railway since, because of the challenges presented by the Lickey Incline, British manufacturers declined to supply. Once steel became available, greater rotational speeds became possible with multiple smaller coupled wheels.
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Placing the throttle into the first power position will cause the traction motors to be connected to the main generator and the latter's field coils to be excited. With excitation applied, the main generator will deliver electricity to the traction motors, resulting in motion. If the locomotive is running "light" (that is, not coupled to the rest of a train) and is not on an ascending grade, it will easily accelerate. On the other hand, if a long train is being started, the locomotive may stall as soon as some of the slack has been taken up, as the drag imposed by the train will exceed the tractive force being developed.
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A small percentage slip can result in a much larger percentage increase in rolling resistance. For example, for pneumatic tires, a 5% slip can translate into a 200% increase in rolling resistance. This is partly because the tractive force applied during this slip is many times greater than the rolling resistance force and thus much more power per unit velocity is being applied (recall power = force x velocity so that power per unit of velocity is just force). So just a small percentage increase in circumferential velocity due to slip can translate into a loss of traction power which may even exceed the power loss due to basic (ordinary) rolling resistance.
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In automotive engineering, drawbar pull is the amount of horizontal force available to a vehicle at the drawbar for accelerating or pulling a load. Drawbar pull is a function of velocity, and in general decreases as the speed of the vehicle increases (due both to increasing resistance and decreasing transmission gear ratios). Drawbar pull is the difference between tractive effort available and tractive effort required to overcome resistance at a specified speed. Drawbar pull data for a vehicle is usually determined by measuring the amount of available tractive force using a dynamometer, and then combining that data with coastdownSAE J1263, Road Load measurement and Dynamometer Simulation Using Coastdown Techniques, dated January 2009.
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CVTs are increasingly found on small cars and especially high-gas-mileage or hybrid vehicles. On these platforms, the torque is limited because the electric motor can provide torque without changing the speed of the engine. By leaving the engine running at the rate that generates the best gas mileage for the given operating conditions, overall mileage can be improved over a system with a smaller number of fixed gears, where the system may be operating at peak efficiency only for a small range of speeds. CVTs are also found in agricultural equipment; due to the high-torque nature of these vehicles, mechanical gears are integrated to provide tractive force at high speeds.
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The incorporation of Alvis Vickers into BAE Systems meant that elements of the work moved to BAE Land Systems, Sweden, formerly known as "Hägglunds", another ex-Alvis company. As with earlier generations of BARV, the main alteration has been the replacement of the turret with a raised superstructure which, in this case, resembles the bridge or wheelhouse of a small ship. The original diesel engine has been retained but the gearing of the transmission had been lowered; this has reduced the vehicle's road speed from , but its tractive force has been increased to . Other modifications include the addition of working platforms, a nosing block, raised air intakes and an auxiliary power unit; this has raised the weight of the vehicle from 42.5 tonnes to 50 tonnes.
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Development of the General Electric (GE) steam turbine locomotives began in late 1936, when GE and the Union Pacific (UP) began collaborating on an oil-powered steam turbine-electric design that they termed a "steam-electric locomotive". To produce an altogether new type of locomotive, GE hoped to adapt mature steam turbine technology from maritime and stationary applications for railroad use. Early GE specifications detailed a streamlined shape, 2+C-C+2 wheel arrangement, and production of and of starting tractive effort (the force generated by a locomotive's prime mover in order to generate motion through tractive force). GE had hoped to deliver a prototype steam turbine locomotive to UP in 1937, but none were completed until December 1938, and were delivered for testing in spring 1939.
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Cross-country skiing trails are also groomed in similar fashion, often with a wide "corduroy" area that allows skate-skiing plus classic ski tracks, imprinted with specialized ski guides. Manufacturers include Formatic, Kässbohrer Geländefahrzeug, Prinoth, Ratrak, Logan Machine Company, Tucker Sno-Cat, Snow Trac, Thiokol, the Ohara Corporation (Japan) and Aztec, SAS (France). Snow groomers can handle very steep gradients due to their low centre of gravity and large contact area, but they can also be assisted by winches. Using cable lengths of up to 1,200 metres and a tractive force of up to 4.8 tonnes, winches can support the machines on steep slopes.Neue Windentechnologie für steilste Hänge (Sherpa-Winde, Prinoth) ISR Internationale Seilbahn-Rundschau 22 April 2011, retrieved 5 September 2014 Snow groomers warn skiers and snowboarders with visual or acoustic signals.
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In the 1920s the Pennsylvania Railroad needed a locomotive for commuter trains. When the first G5s rolled out of the Juniata shops in 1923, the Pennsylvania Railroad hadn't built a 4-6-0 in more than two decades. Mechanical Engineer William F. Kiesel, Jr. who designed the engine used the boiler from an E6s Atlantic and designed one of the largest and most powerful ten-wheelers ever built. Smaller drive wheels than an Atlantic and the lack of a trailing truck put more weight on the drivers and produced an engine with great power and acceleration but a lower top speed. The 4-6-0 wheel arrangement could provide sufficient tractive effort, (41,000 lbs of tractive force) but at the same time, allow the locomotive to accelerate the train more quickly.
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An equivalent measurement on land is known as drawbar pull, or tractive force, which is used to measure the total horizontal force generated by a locomotive, a piece of heavy machinery such as a tractor, or a truck, (specifically a ballast tractor), which is utilized to move a load. Bollard pull is primarily (but not only) used for measuring the strength of tugboats, with the largest commercial harbour tugboats in the 2000-2010s having around of bollard pull, which is described as above "normal" tugboats. The worlds strongest tug is Island Victory (Vard Brevik 831) of Island Offshore, with a bollard pull of . Island Victory is not a typical tug, rather it is a special class of ship used in the petroleum industry called an Anchor Handling Tug Supply vessel.
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Mechanisation and automation strive to reduce the amount of manual labour required for production. The motives for this reduction of effort may be to remove drudgery from people's lives; to lower the unit cost of production; or, as mechanisation evolves into automation, to bring greater flexibility (easier redesign, lower lead time) to production. Mechanisation occurred first in tasks that required either little dexterity or at least a narrow repertoire of dextrous movements, such as providing motive force or tractive force (locomotives; traction engines; marine steam engines; early cars, trucks, and tractors); digging, loading, and unloading bulk materials (steam shovels, early loaders); or weaving uncomplicated cloth (early looms). For example, Henry Ford described his efforts to mechanise agricultural tasks such as tillage as relieving drudgery by transferring physical burdens from human and animal bodies to iron and steel machinery.
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This redirected the plough's resistance into downward force on the drive wheels, which enabled Ferguson's tractor to be much lighter and more manoeuvrable than earlier models of farm tractor with equivalent tractive force and traction. As a result his tractor could operate on soft ground and caused less compacting damage to the soil in comparison with other tractors of the time, and it could produce given amounts of work with less time and fuel. The hydraulically operated and controlled three-point hitch used the draft of the mounted tool to moderate the depth of the tool and therefore the load on the tractor (automatic depth control or draft control). In addition, the three-point hitch would prevent the tractor from flipping backwards on the drive wheels if the implement being dragged were to hit a rock or other immovable obstruction.
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As they were true general- purpose locomotives, they were well suited for use in hotshot freight service, fast passenger service, or even local runs (Four other T-54s - 1500, 1502, 1510, and 1521 - were leased to the Texas and New Orleans Railroad during the late 1940s, who greatly admired the locomotives). After experimenting with diesel locomotives for the next decade after the start of World War II (during which 1522 and 15 other T-54s were upgraded with booster engines, 210-psi boilers, and 69 1/2-inch drivers, increasing their tractive force to 65,550 lbs. and their top speed to 90 mph), the Frisco Railway begin to rapidly dieselize during the late 1940s and early 1950s. Ultimately, all scheduled steam operations ended on the Frisco in February 1952 and reserve steam operations ended in 1956.
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The twenty Series 1 locomotives were identical to the Class 6E in most respects including their AEI-283AZ traction motors, power output, tractive force and body dimensions. The only visually obvious distinguishing feature to tell the Class 6E1, Series 1 apart was its new design bogies with their distinctive traction struts and linkages. Bogie frame and wheels Together with the unit's electronic wheelslip detection system, these traction struts, mounted between the linkages on the bogies and the locomotive body and colloquially referred to as grasshopper legs, ensured the maximum transfer of power to the rails without causing wheel-slip by reducing the adhesion of the leading bogie and increasing that of the trailing bogie by as much as 15% upon starting off. This feature was controlled by electronic wheel-slip detection devices and an electric weight transfer relay which reduced the anchor current to the leading bogie by as much as 50A in notches 2 to 16.
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