127-500: Scammell Lorries Limited was a British manufacturer of trucks , particularly specialist and military off-road vehicles, between 1921 and 1988. From 1955 Scammell was part of Leyland Motors . Scammell started as a late- Victorian period wheelwright and coach -building business, G Scammell & Nephew Ltd in Spitalfields , London . George Scammell, the founder, was joined by his nephew Richard and Richard's sons Alfred and James. By
254-460: A Motor Panels -supplied steel cab, available in sleeper- or day-cab forms. It had the option of Detroit Diesel , Cummins , Rolls-Royce or Leyland engines. The Crusader was used by the British Army as a 6×4 tow-truck (with EKA underlift equipment) and as a 6x4 tractor unit normally used for towing 35–tonne plant trailers or 30–tonne tank bridge transport trailers. A recovery variant
381-406: A fifth wheel hitch. Box trucks have walls and a roof, making an enclosed load space. The rear has doors for unloading; a side door is sometimes fitted. Chassis cab trucks have a fully enclosed cab at the front, with bare chassis frame-rails behind, suitable for subsequent permanent attachment of a specialized payload, like a fire-truck or ambulance body. Concrete mixers have
508-414: A vehicle to its wheels and allows relative motion between the two. Suspension systems must support both road holding/ handling and ride quality , which are at odds with each other. The tuning of suspensions involves finding the right compromise. It is important for the suspension to keep the road wheel in contact with the road surface as much as possible, because all the road or ground forces acting on
635-403: A 2,090-cc, side-valve petrol engine in both models and a diesel version with a Perkins engine. The company mainly concentrated on articulated and rigid eight-wheeler lorries, from the 1920s. One vehicle not in those lines that became well-known was the 6×4 Pioneer . This was an off-highway, heavy haulage tractor, first produced in 1927. It showed outstanding cross-country performance due to
762-485: A 25 mph (40 km/h) speed governor as they are classified as low-speed vehicles. These vehicles have found uses in construction, large campuses (government, university, and industrial), agriculture, cattle ranches, amusement parks, and replacements for golf carts. Major mini-truck manufacturers and their brands include: Daihatsu Hijet , Honda Acty , Tata Ace , Mazda Scrum , Mitsubishi Minicab , Subaru Sambar , and Suzuki Carry . Light trucks are car-sized (in
889-529: A commercial vehicle without a trailer or other articulation is formally a "straight truck" while one designed specifically to pull a trailer is not a truck but a " tractor ". The majority of trucks currently in use are powered by diesel engines , although small- to medium-size trucks with gasoline engines exist in North America . Electrically powered trucks are more popular in China and Europe than elsewhere. In
1016-401: A common construction: they are made of a chassis , a cab , an area for placing cargo or equipment, axles , suspension and roadwheels , an engine and a drivetrain . Pneumatic , hydraulic , water , and electrical systems may also be present. Many also tow one or more trailers or semi-trailers. The "cab", or "cabin" is an enclosed space where the driver is seated. A " sleeper " is
1143-704: A compartment attached to or integral with the cab where the driver can rest while not driving, sometimes seen in semi-trailer trucks. There are several cab configurations: A further step from this is the side loading forklift that can be described as a specially fabricated vehicle with the same properties as a truck of this type, in addition to the ability to pick up its own load. Most small trucks such as sport utility vehicles (SUVs), vans or pickups , and even light medium-duty trucks in North America, China, and Russia use gasoline engines (petrol engines), but many diesel engined models are now being produced. Most of
1270-562: A factory to the nearest railway station. The first semi-trailer appeared in 1881, towed by a steam tractor manufactured by De Dion-Bouton . Steam-powered wagons were sold in France and the United States until the eve of World War I , and 1935 in the United Kingdom, when a change in road tax rules made them uneconomic against the new diesel lorries. In 1895, Karl Benz designed and built
1397-595: A glass-fibre cab designed by Scammell – for the Mark 2 and 3 versions a new Michelotti -designed "cheesegrater" fibreglass cab as used on the 2nd and 3rd versions of the Routeman Rigid was fitted. Early versions were equipped with Scammell's own "gate-change" gearbox but subsequent versions were fitted with AEC and David Brown gearboxes. Engines fitted included the Leyland 680, Gardner 150 and Rolls-Royce 220. The Trunker
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#17328516596741524-463: A high-speed off-road vehicle encounters. Damping is the control of motion or oscillation, as seen with the use of hydraulic gates and valves in a vehicle's shock absorber. This may also vary, intentionally or unintentionally. Like spring rate, the optimal damping for comfort may be less, than for control. Damping controls the travel speed and resistance of the vehicle's suspension. An undamped car will oscillate up and down. With proper damping levels,
1651-406: A ladder if tipped on end. The rails consist of a tall vertical section (two if boxed) and two shorter horizontal flanges. The height of the vertical section provides opposition to vertical flex when weight is applied to the top of the frame (beam resistance). Though typically flat the whole length on heavy-duty trucks, the rails may sometimes be tapered or arched for clearance around the engine or over
1778-420: A manual transmission with synchromesh (synchronizers). Bigger trucks often use manual transmissions without synchronizers, saving bulk and weight, although synchromesh transmissions are used in larger trucks as well. Transmissions without synchronizers, known as "crash boxes", require double-clutching for each shift, (which can lead to repetitive motion injuries), or a technique known colloquially as "floating",
1905-545: A manual transmission, while conventional automatic or automated manual transmissions would have anything from 5 to 12 gears. Almost all heavy truck transmissions are of the "range and split" (double H shift pattern) type, where range change and so‑called half gears or splits are air operated and always preselected before the main gear selection. A truck frame consists of two parallel boxed (tubular) or C‑shaped rails, or beams, held together by crossmembers . These frames are referred to as ladder frames due to their resemblance to
2032-407: A method of changing gears which does not use the clutch, except for starts and stops, due to the physical effort of double-clutching, especially with non-power-assisted clutches, faster shifts, and less clutch wear. Double-clutching allows the driver to control the engine and transmission revolutions to synchronize so that a smooth shift can be made; for example, when upshifting, the accelerator pedal
2159-500: A more uncertain origin, but probably has its roots in the rail transport industry, where the word is known to have been used in 1838 to refer to a type of truck (a goods wagon as in British usage, not a bogie as in the American), specifically a large flat wagon. It might derive from the verb lurry (to carry or drag along, or to lug) which was in use as early as 1664, but that association
2286-558: A new company, Scammell Lorries Ltd in July 1922, with Lt. Col. Scammell as managing director. The new firm built a new factory at Tolpits Lane, Watford , next to Watford West railway station on the branch line from Watford Junction to Croxley Green . The original company remained in business in Fashion Street, Spitalfields refurbishing and bodybuilding until taken over in 1965 by York Trailer Co. In 1929, Scammell designed and manufactured
2413-515: A rear body (with half-height roller shutter access doors), winch, and dynamo with the ballast block underneath. Eighteen were built, to varying specifications (not all had the body fitted, for example), between December 1945 and September 1948. Seventeen have been preserved. There are many look-alike Scammell tractors, but genuine Showtracs had a special "Showtrac" badge on the radiator, and a full-width cab. Preserved by Roger Austin, Raunds, Northamptonshire, then his family. The Handyman initially used
2540-513: A reorganisation of the Leyland Group, with heavy haul after the closure of the old Thornycroft works in 1972 concentrated on the newly named Scammell Motors site at Watford. The Thornycroft 6x4 Nubian heavy dumptruck was the first transfer inwards, regularly adapted for the military, followed by the lighter LD55 6x4 dumptruck. In the late 1970s, the Contractor Mk2 was developed, together with
2667-401: A roof and floor, used for transporting fresh and frozen cargo such as ice cream, food, vegetables, and prescription drugs. They are mostly equipped with double-wing rear doors, but a side door is sometimes fitted. Refuse trucks have a specialized body for collecting and, often, compacting trash collected from municipal, commercial, and industrial sites. This application has the widest use of
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#17328516596742794-544: A rotating drum on an inclined axis, rotating in one direction to mix, and in the other to discharge the concrete down chutes. Because of the weight and power requirements of the drum body and rough construction sites, mixers have to be very heavy duty. Dual drive/Steer trucks are vehicles used to steer the rear of trailers . Dump trucks ("tippers" in the UK) transport loose material such as sand, gravel, or dirt for construction. A typical dump truck has an open-box bed, which
2921-558: A series of glass-reinforced plastic "spring"-like designs. The first to be redesigned was the Routeman, followed by the Handyman. In 1967, the 'Scarab' was replaced by the 'Townsman', which also had a GRP body. The factory also designed the 6x4 Contractor equipped with a Cummins 335 engine, Lipe clutch and Fuller semi-automatic gearbox, that went into production in 1964. Offered with a choice of Leyland 24 tonne or Scammell 30 and 40 tonne bogies,
3048-621: A similar vehicle, the Cob, four years earlier. From 1937, a Citroën Traction Avant powered version was made under licence in France, by Chenard-Walcker-FAR , known as the Pony Mécanique. This continued in production, in various versions, until 1970. In the late 1940s, the Mechanical Horse was superseded by the Scammell Scarab , with similar features, but a much less angular cab and now with
3175-704: A six-axle truck may have a maximum weight of 44 t (97,000 lb) or more. Off-road trucks include standard, extra heavy-duty highway-legal trucks, typically outfitted with off-road features such as a front driving axle and special tires for applications such as logging and construction, and purpose-built off-road vehicles unconstrained by weight limits, such as the Liebherr T 282B mining truck. Australia has complex regulations over weight and length, including axle spacing, type of axle/axle group, rear overhang, kingpin to rear of trailer, drawbar length, ground clearance, as well as height and width laws. These limits are some of
3302-405: A swinging motion instead of the jolting up-and-down of spring suspension. In 1901, Mors of Paris first fitted an automobile with shock absorbers . With the advantage of a damped suspension system on his 'Mors Machine', Henri Fournier won the prestigious Paris-to-Berlin race on 20 June 1901. Fournier's superior time was 11 hours 46 minutes and 10 seconds, while the best competitor
3429-411: A truck, of a trailer, from axle to hitch point, kingpin to rear of trailer, and turning radius are all regulated. In additions, there are special rules for carrying containers, and countries can set their own rules for local traffic. The United States Federal Bridge Law deals with the relation between the gross weight of the truck, the number of axles, the weight on and the spacing between the axles that
3556-439: A turning point in road transport history. Mechanical transport was seen to work, proving its vast potential beyond doubt to forward-thinking companies such as Scammell. George Scammell's great nephew, Lt. Col. Alfred Scammell, was injured and invalided out of the army, and he was able to apply the practical experience he had gained during the war and began developing the articulated six wheeler. Percy G Hugh, chief designer, conceived
3683-565: A two-axle model, powered initially by a Rolls-Royce Eagle six-cylinder diesel engine, rated at 220 or 280 bhp, depending on customers' preferences. This new model appeared at the November 1969 Scottish Motor Show at Kelvin Hall . Scammell went on to develop a heavy haulage model, the Samson, basically a four-axle 8x4 Crusader. It sold in limited numbers in a specialised market sector. The 1970s started with
3810-443: A variety of beam axles and independent suspensions are used. For rear-wheel drive cars , rear suspension has many constraints, and the development of the superior, but more expensive independent suspension layout has been difficult. Henry Ford 's Model T used a torque tube to restrain this force, for his differential was attached to the chassis by a lateral leaf spring and two narrow rods. The torque tube surrounded
3937-413: A vehicle can, and usually, does differ front-to-rear, which allows for the tuning ability of a vehicle for transient and steady-state handling. The roll rate of a vehicle does not change the total amount of weight transfer on the vehicle, but shifts the speed and percentage of weight transferred on a particular axle to another axle through the vehicle chassis. Generally, the higher the roll rate on an axle of
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4064-416: A vehicle, the faster and higher percentage the weight transfer on that axle . By 2021, some vehicles were offering dynamic roll control with ride-height adjustable air suspension and adaptive dampers. Roll couple percentage is a simplified method of describing lateral load transfer distribution front to rear, and subsequently handling balance. It is the effective wheel rate, in roll, of each axle of
4191-466: A vehicle. Roll rate is analogous to a vehicle's ride rate, but for actions that include lateral accelerations, causing a vehicle's sprung mass to roll. It is expressed as torque per degree of roll of the vehicle sprung mass. It is influenced by factors including but not limited to vehicle sprung mass, track width, CG height, spring and damper rates, roll centre heights of front and rear, anti-roll bar stiffness and tire pressure/construction. The roll rate of
4318-611: A version of their Xebra electric tricycle (licensable in the U.S. as a motorcycle). Popular in Europe and Asia, many mini-trucks are factory redesigns of light automobiles, usually with monocoque bodies. Specialized designs with substantial frames such as the Italian Piaggio shown here are based upon Japanese designs (in this case by Daihatsu ) and are popular for use in "old town" sections of European cities that often have very narrow alleyways. Regardless of name, these small trucks serve
4445-566: A wide range of uses. In Japan, they are regulated under the Kei car laws, which allow vehicle owners a break in taxes for buying a smaller and less-powerful vehicle (currently, the engine is limited to 660 cc displacement). These vehicles are used as on-road utility vehicles in Japan. These Japanese-made mini-trucks that were manufactured for on-road use are competing with off-road ATVs in the United States, and import regulations require that these mini-trucks have
4572-447: A year. The truck included a 'repair by replacement' philosophy to cut downtime and the consequences of unscheduled maintenance. The drive line included a 9.3-litre GM Detroit Diesel 8V71N two-stroke diesel engine , rated at 273 bhp. This drove through a Fuller RoadRanger 16-speed constant-mesh gear box, to an Albion double-drive and two-spring bogie, using double reduction and cross lockable drive axles. The final reduction took place in
4699-491: A yoke that goes around the differential, below and behind it. This method has had little use in the United States . Its use around 1900 was probably due to the poor quality of tires, which wore out quickly. By removing a good deal of unsprung weight , as independent rear suspensions do, it made them last longer. Rear-wheel drive vehicles today frequently use a fairly complex fully-independent, multi-link suspension to locate
4826-489: Is called a dumb iron . In 2002, a new passive suspension component, the inerter , was invented by Malcolm C. Smith . This has the ability to increase the effective inertia of wheel suspension using a geared flywheel, but without adding significant mass. It was initially employed in Formula One in secrecy, but has since spread to wider motorsport. For front-wheel drive cars , rear suspension has few constraints, and
4953-412: Is determined by the instantaneous front view swing arm (FVSA) length of suspension geometry, or in other words, the tendency of the tire to camber inward when compressed in bump. Roll center height is a product of suspension instant center heights and is a useful metric in analyzing weight transfer effects, body roll and front to rear roll stiffness distribution. Conventionally, roll stiffness distribution
5080-454: Is different from what it is under acceleration and braking. This variation in wheel rate may be minimised by locating the spring as close to the wheel as possible. Wheel rates are usually summed and compared with the sprung mass of a vehicle to create a "ride rate" and the corresponding suspension natural frequency in ride (also referred to as "heave"). This can be useful in creating a metric for suspension stiffness and travel requirements for
5207-474: Is equal to the G-force times the sprung weight times the roll moment arm length divided by the effective track width. The front sprung weight transfer is calculated by multiplying the roll couple percentage times the total sprung weight transfer. The rear is the total minus the front transfer. Jacking forces are the sum of the vertical force components experienced by suspension links. The resultant force acts to lift
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5334-427: Is hinged at the rear and lifts at the front, allowing the material in the bed to be unloaded ("dumped") on the ground behind the truck. Flatbed trucks have an entirely flat, level platform body. This allows for quick and easy loading but has no protection for the load. Hanging or removable sides are sometimes fitted, often in the form of a stakebody . Refrigerator trucks have insulated panels as walls and
5461-422: Is in neutral, it allows the engine speed to drop and synchronize engine and transmission revolutions relative to the road speed. Downshifting is performed in a similar fashion, except the engine speed is now required to increase (while the transmission is in neutral) just the right amount in order to achieve the synchronization for a smooth, non-collision gear change. "Skip changing" is also widely used; in principle,
5588-441: Is key information used in finding the force-based roll center as well. In this respect, the instant centers are more important to the handling of the vehicle, than the kinematic roll center alone, in that the ratio of geometric-to-elastic weight transfer is determined by the forces at the tires and their directions in relation to the position of their respective instant centers. Anti-dive and anti-squat are percentages that indicate
5715-425: Is limited by contact of suspension members (See Triumph TR3B .) Many off-road vehicles , such as desert racers, use straps called "limiting straps" to limit the suspensions' downward travel to a point within safe limits for the linkages and shock absorbers. This is necessary, since these trucks are intended to travel over very rough terrain at high speeds, and even become airborne at times. Without something to limit
5842-564: Is most often made as vans. Medium trucks are larger than light but smaller than heavy trucks. In the US, they are defined as weighing between 13,000 and 33,000 lb (5.9 and 15.0 t). For the UK and the EU the weight is between 3.5 and 7.5 t (7,700 and 16,500 lb). Local delivery and public service ( dump trucks , garbage trucks and fire-fighting trucks ) are normally around this size. Heavy trucks are
5969-455: Is mostly reserved for larger vehicles. In Australia and New Zealand, a pickup truck is frequently called a ute (short for "utility" vehicle), while in South Africa it is called a bakkie ( Afrikaans : "small open container"). In the United Kingdom, India, Malaysia, Singapore, Ireland, and Hong Kong lorry is used instead of truck , but only for the medium and heavy types, while truck
6096-463: Is not definitive. The expanded meaning of lorry , "self-propelled vehicle for carrying goods", has been in usage since 1911. In the United States, Canada, and the Philippines, "truck" is usually reserved for commercial vehicles larger than regular passenger cars, but includes large SUVs, pickups, and other vehicles with an open load bed. In Australia, New Zealand and South Africa, the word "truck"
6223-412: Is released and the clutch pedal is depressed while the gear lever is moved into neutral, the clutch pedal is then released and quickly pushed down again while the gear lever is moved to the next higher gear. Finally, the clutch pedal is released and the accelerator pedal pushed down to obtain the required engine speed. Although this is a relatively fast movement, perhaps a second or so while the transmission
6350-625: Is space for two bunks behind the front seats. Due to the front axle lock angle, the Commander is highly maneuverable and can negotiate a 'T' intersection with only 9.15 meters between the walls. In 1988 the Leyland group including Scammell company was bought by DAF, the rights to the Commander were sold Unipower Ltd, who opened a new plant in West Watford. In 1990 during the operation Desert Storm 70 Scammell Commander heavy tank transporters were used to transport 40 types of various military cargo. Each of
6477-558: Is still used today in larger vehicles, mainly mounted in the rear suspension. Leaf springs were the first modern suspension system, and, along with advances in the construction of roads , heralded the single greatest improvement in road transport until the advent of the automobile . The British steel springs were not well-suited for use on America 's rough roads of the time, so the Abbot-Downing Company of Concord, New Hampshire re-introduced leather strap suspension, which gave
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#17328516596746604-410: Is the "bump-stop", which protects the suspension and the vehicle (as well as the occupants) from the violent "bottoming" of the suspension, caused when an obstruction (or a hard landing) causes suspension to run out of upward travel without fully absorbing the energy of the stroke. Without bump-stops, a vehicle that "bottoms out", will experience a very hard shock when the suspension contacts the bottom of
6731-660: Is tuned adjusting antiroll bars rather than roll center height (as both tend to have a similar effect on the sprung mass), but the height of the roll center is significant when considering the amount of jacking forces experienced. Due to the fact that the wheel and tire's motion is constrained by the vehicle's suspension links, the motion of the wheel package in the front view will scribe an imaginary arc in space with an "instantaneous center" of rotation at any given point along its path. The instant center for any wheel package can be found by following imaginary lines drawn through suspension links to their intersection point. A component of
6858-516: Is used almost exclusively to refer to pickups . Often produced as variations of golf cars , with internal combustion or battery electric drive , these are used typically for off-highway use on estates, golf courses, and parks. While not suitable for highway use some variations may be licensed as slow speed vehicles for operation on streets, generally as a body variation of a neighborhood electric vehicle . A few manufactures produce specialized chassis for this type of vehicle, while Zap Motors markets
6985-545: The European Union , vehicles with a gross combination mass of up to 3.5 t (3.4 long tons; 3.9 short tons) are defined as light commercial vehicles , and those over as large goods vehicles . Trucks and cars have a common ancestor: the steam-powered fardier Nicolas-Joseph Cugnot built in 1769. However, steam wagons were not common until the mid-19th century. The roads of the time, built for horse and carriages, limited these vehicles to very short hauls, usually from
7112-535: The Scammell Commander tank transporter for the British Army . Fitted with the Rolls-Royce CV12TCE 26-litre, 48-valve dual-turbocharged 625 hp intercooled V12 diesel engine, semi-automatic gearbox and Scammell 40-ton bogie, it was plated at 100 ton+ GTW. Because it was intended as part of the strategy to defend West Germany's eastern Iron Curtain border against tank attack, it was designed to achieve
7239-637: The Vietnam War was branded with the Scammell name, most of the remaining units were branded Leyland . Two trailer specifications were used, a 24-wheel float with 16 wheel dolly trailer for transporting the Australian Centurion tank or US Patton tank in Vietnam. The other trailer was a 40 Ton 12 wheel Steco folding goose neck trailer for the engineering plant. The Crusader was a 4×2 or 6×4 tractor that used
7366-429: The cab-over configuration in North America, to provide better maneuverability in tight situations. They are also among the most severe-duty and highest GVWR trucks on public roads. Semi-tractors ("artics" in the UK) have a fifth wheel for towing a semi-trailer instead of a body. Suspension (vehicle) Suspension is the system of tires , tire air, springs , shock absorbers and linkages that connects
7493-422: The diesel engine did not appear in production trucks until Benz introduced it in 1923. The diesel engine was not common in trucks in Europe until the 1930s. In the United States, Autocar introduced diesel engines for heavy applications in the mid-1930s. Demand was high enough that Autocar launched the "DC" model (diesel conventional) in 1939. However, it took much longer for diesel engines to be broadly accepted in
7620-461: The phase-out of fossil fuel vehicles includes trucks. According to The Economist magazine "Electric lorries will probably run on hydrogen, not batteries, which are too expensive." Other researchers say that once faster chargers are available batteries will become competitive against diesel for all, except perhaps the heaviest, trucks. Small trucks use the same type of transmissions as almost all cars, having either an automatic transmission or
7747-465: The "100 Tonner" low loader. Only two were produced; the first was delivered to Marston Road Services, Liverpool , for the transportation of steam engines to Liverpool docks . Scammell were also looking for new markets, and diversified into four- and six-wheel rigid (nonarticulated) designs. The 'Rigid Six-wheeler' found some success and, with its balloon tyres, at last permitted sustained high-speed, long-distance road operation. In 1934, Scammell produced
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#17328516596747874-438: The 1930s to the 1970s. The system uses longitudinal leaf springs attached both forward and behind the differential of the live axle . These springs transmit torque to the frame. Although scorned by many European car makers of the time, it was accepted by American car makers, because it was inexpensive to manufacture. Also, the dynamic defects of this design were suppressed by the enormous weight of U.S. passenger vehicles before
8001-484: The Commander tows a special semi-trailer onto which tanks can be tail-loaded using a hydraulic 20–tonne capacity winch. A prominent bonnet houses the vehicle's Perkins (Rolls-Royce) CV 12 TCE V12 and although the Commander is powered by the Perkins/Rolls-Royce engine, other types were also proposed – one of the prototypes used a Cummins KTA 600 diesel. The cab has provision for up to three or four passengers and there
8128-530: The Contractor was popular in the UK for 240+ ton GTW operation, overseas heavy haul, and with the military for tank transport. In 1964, Scammell assembled 38 BUT RETB/1 trolleybuses for use in Wellington , New Zealand. Scammell launched the three-axle 6x4 Crusader at London's 1968 Earl's Court Commercial Vehicle Show. The truck was designed for high-speed long-distance transport, typically to cover 250,000 miles
8255-467: The G-force times the front unsprung center of gravity height divided by the front track width. The same is true for the rear. Sprung weight transfer is the weight transferred by only the weight of the vehicle resting on its springs, and not by total vehicle weight. Calculating this requires knowing the vehicle's sprung weight (total weight less the unsprung weight), the front and rear roll center heights, and
8382-480: The Leyland group, allowing the replacement of the "lightweight" range with the: Both the tractor units could be configured up to 50 tons (50.8 Tonnes or 55 short tons ), and complemented by the full range of Scammell trailers made at the Moor Park works, allowed the company to continue production in specialist and military markets. In the 1960s, Scammell contracted Giovanni Michelotti to design its cabs, resulting in
8509-573: The Oshkosh M1070F HET . The Commander is powered by the 26.7L Rolls-Royce/Perkins CV12 TCE twin turbocharged diesel engine that produces approximately 625 hp (466 kW) and is coupled to an Allison automatic transmission. The Scammell Commander CV12 engine is very similar to the ones used in the Challenger 1 and 2 main battle tanks but with an increased power output of around 1,200 bhp (890 kW). Designed to tow loads up to 65 tonnes,
8636-535: The US, no more than 13,900 lb (6.3 t)) and are used by individuals and businesses alike. In the EU they may not weigh more than 3.5 t (7,700 lb) and are allowed to be driven with a driving licence for cars. Pickup trucks , called utes in Australia and New Zealand, are common in North America and some regions of Latin America, Asia, and Africa, but not so in Europe, where this size of commercial vehicle
8763-555: The US: gasoline engines were still in use on heavy trucks in the 1970s. Electrically powered trucks predate internal combustion ones and have been continuously available since the mid-19th-century. In the 1920s Autocar Trucks was the first of the major truck manufacturers to offer a range of electric trucks for sale. Electric trucks were successful for urban delivery roles and as specialized work vehicles like forklifts and pushback tugs . The higher energy density of liquid fuels soon led to
8890-461: The advances elsewhere, still highly praises anything which carries a Scammell badge. So much so that they have amassed a large collection of older recovery vehicles and later model classics that are restored for posterity, and in many cases could still go to work if required. Post war, foreign competition and rationalisation of the UK manufacturers led to Scammell coming under Leyland Motors in 1955. This provided access to ready-made components within
9017-403: The axles. The holes in rails are used either for mounting vehicle components and running wires and hoses or measuring and adjusting the orientation of the rails at the factory or repair shop. The frame is usually made of steel , but can be made (whole or in part) of aluminum for a lighter weight. A tow bar may be found attached at one or both ends, but heavy tractors almost always make use of
9144-428: The car will settle back to a normal state in a minimal amount of time. Most damping in modern vehicles can be controlled by increasing or decreasing the resistance to fluid flow in the shock absorber. See dependent and independent below. Camber changes due to wheel travel, body roll and suspension system deflection or compliance. In general, a tire wears and brakes best at -1 to -2° of camber from vertical. Depending on
9271-414: The case of the straight axle. When viewed from the front or rear, the wheel rate can be measured by the means above. Yet, because the wheels are not independent, when viewed from the side under acceleration or braking, the pivot point is at infinity (because both wheels have moved) and the spring is directly inline with the wheel contact patch. The result is often, that the effective wheel rate under cornering
9398-476: The change in deflection of the spring. Vehicles that carry heavy loads, will often have heavier springs to compensate for the additional weight that would otherwise collapse a vehicle to the bottom of its travel (stroke). Heavier springs are also used in performance applications, where the loading conditions experienced are more significant. Springs that are too hard or too soft cause the suspension to become ineffective – mostly because they fail to properly isolate
9525-596: The complementary S26 range of heavy-haul 4x2, 6x2 and 6x4 tractors, which was a parts-bin build from the Roadtrain and 24 components. In 1986, Scammell tendered for the British Army hooklift DROPS tender, using the newly developed 8x6 variant of the S24. This was equipped with a Rolls-Royce 350 engine, ZF automatic gearbox and Kirkstall axles. However, shortly after winning the contract to supply 1,522 such vehicles, Leyland group
9652-431: The decline of electric-powered trucks in favor of, first, gasoline, and then diesel and CNG-fueled engines until battery technology advanced in the 2000s when new chemistries and higher-volume production broadened the range of applicability of electric propulsion to trucks in many more roles. Today, manufacturers are electrifying all trucks ahead of national regulatory requirements, with long-range over-the-road trucks being
9779-495: The degree to which the front dives under braking, and the rear squats under acceleration. They can be thought of as the counterparts for braking and acceleration, as jacking forces are to cornering. The main reason for the difference is due to the different design goals between front and rear suspension, whereas suspension is usually symmetrical between the left and the right of the vehicle. The method of determining anti-dive or anti-squat depends on whether suspension linkages react to
9906-659: The design that included the patent beam bogie rear axle , with 2 feet (1 m) of vertical movement for each of the rear wheels. This design was the work of Oliver Danson North . The Pioneer proved popular in the oil field and forestry ( logging ) markets, and formed the basis of the British Army 's World War II R100 30-ton tank transporter . With the outbreak of war, development of new vehicles stopped and production concentrated on military Pioneers for use as artillery tractors, recovery and transporter vehicles. In 2024, British-based On Scene Magazine featured an interview with Dave Crouch of UK firm Crouch Recovery, who, despite
10033-464: The distance between wheel centers (wheelbase in the case of braking, or track width in the case of cornering), the height of the center of gravity, the mass of the vehicle, and the amount of acceleration experienced. The speed at which weight transfer occurs, as well as through which components it transfers, is complex, and is determined by many factors; including, but not limited to: roll center height, spring and damper rates, anti-roll bar stiffness, and
10160-407: The early Egyptians . Ancient military engineers used leaf springs in the form of bows to power their siege engines , with little success at first. The use of leaf springs in catapults was later refined and made to work years later. Springs were not only made of metal; a sturdy tree branch could be used as a spring, such as with a bow. Horse-drawn carriages and Ford Model T used this system, and it
10287-427: The early 1900s, the firm had become financially stable, providing maintenance to customers of Foden steam wagons. One such customer, Edward Rudd, had imported a Knox Automobile tractor from the United States, and impressed with its low weight/high hauling power had asked Scammell if they could make a similar model of their own. However, the outbreak of World War I in 1914 stopped the project and presented itself as
10414-483: The first internal combustion truck. Later that year some of Benz's trucks were modified to become busses by Netphener . A year later, in 1896, another internal combustion engine truck was built by Gottlieb Daimler , the Daimler Motor Lastwagen . Other companies, such as Peugeot , Renault and Büssing , also built their own versions. The first truck in the United States was built by Autocar in 1899 and
10541-430: The frame or body, which is transferred to the occupants and every connector and weld on the vehicle. Factory vehicles often come with plain rubber "nubs" to absorb the worst of the forces, and insulate the shock. A desert race vehicle, which must routinely absorb far higher impact forces, might be provided with pneumatic or hydro-pneumatic bump-stops. These are essentially miniature shock absorbers (dampers) that are fixed to
10668-413: The ground, which reduces the overall amount of compression available to the suspension, and increases the amount of body lean. Performance vehicles can sometimes have spring rate requirements other than vehicle weight and load. Wheel rate is the effective spring rate when measured at the wheel, as opposed to simply measuring the spring rate alone. Wheel rate is usually equal to or considerably less than
10795-443: The heavier trucks use four-stroke diesel engines with a turbocharger and intercooler . Huge off-highway trucks use locomotive-type engines such as a V12 Detroit Diesel two stroke engine. A large proportion of refuse trucks in the United States employ CNG (compressed natural gas) engines for their low fuel cost and reduced carbon emissions. A significant proportion of North American manufactured trucks use an engine built by
10922-440: The highest in the world, a B-double can weigh 62.5 t (61.5 long tons; 68.9 short tons) and be 25 m (82 ft) long, and road trains used in the outback can weigh 172 t (169.3 long tons; 189.6 short tons) and be 53.5 m (176 ft) long. The European Union also has complex regulations. The number and spacing of axles, steering, single or dual tires, and suspension type all affect maximum weights. Length of
11049-635: The hubs to give better ground clearance under the differential housings. Scammell used the same rear bogie on its highly successful 24-ton Double Drive Routeman 8x4 tipper chassis, launched at the same exhibition. As most contemporary 32-ton and maximum capacity trucks in the UK had engine power ratings of between 150 and 220 bhp, the Crusader's 273 bhp attracted immediate attention, much of it unfavourable from deeply conservative operators. With active encouragement from Walter Batstone, then transport engineering boss at British Road Services , Scammell quickly developed
11176-417: The idea and at the 1920 Commercial Motor Show, 50 orders were taken for the new design. The vehicle's very low axle weight allowed it to carry 7.5 tonnes (7.4 long tons; 8.3 short tons) payload legally at 12 miles per hour (19 km/h), rather than being limited to 5 mph. Scammell started production of the 7.5-ton articulated vehicle in 1920. Needing to move to new premises, Scammell & Nephew floated
11303-529: The implementation of the Corporate Average Fuel Economy (CAFE) standard. Another Frenchman invented the De Dion tube , which is sometimes called "semi-independent". Like true independent rear suspension, this employs two universal joints , or their equivalent from the centre of the differential to each wheel. But the wheels cannot entirely rise and fall independently of each other; they are tied by
11430-430: The kinematic design of suspension links. In most conventional applications, when weight is transferred through intentionally compliant elements, such as springs, dampers, and anti-roll bars, the weight transfer is said to be "elastic", while the weight which is transferred through more rigid suspension links, such as A-arms and toe links, is said to be "geometric". Unsprung weight transfer is calculated based on weight of
11557-407: The largest on-road trucks, Class 8 . These include vocational applications such as heavy dump trucks, concrete pump trucks, and refuse hauling, as well as ubiquitous long-haul 4x2 and 6×4 tractor units . Road damage and wear increase very rapidly with the axle weight. The number of steering axles and the suspension type also influence the amount of the road wear. In many countries with good roads
11684-514: The last remaining major independent engine manufacturer ( Cummins ) but most global OEMs such as Volvo Trucks and Daimler AG promote their own "captive" engines. In the European Union, all new truck engines must comply with Euro VI emission regulations, and Euro 7 from the late 2020s has stricter exhaust limits and also limits air pollution from brakes and tires . As of 2019 several alternative technologies are competing to displace
11811-466: The lever arm ratio would be 0.75:1. The wheel rate is calculated by taking the square of the ratio (0.5625) times the spring rate, thus obtaining 281.25 lbs/inch (49.25 N/mm). The ratio is squared because it has two effects on the wheel rate: it applies to both the force and the distance traveled. Wheel rate on independent suspension is fairly straightforward. However, special consideration must be taken with some non-independent suspension designs. Take
11938-647: The most challenging. Truck is used in American English ; the British English equivalent is lorry. The first known usage of "truck" was in 1611 when it referred to the small strong wheels on ships' cannon carriages, and comes from "Trokhos" (Greek) = "wheel". In its extended usage, it came to refer to carts for carrying heavy loads, a meaning known since 1771. Its expanded application to "motor-powered load carrier" has been in usage since 1930, shortened from "motor truck", which dates back to 1901. "Lorry" has
12065-424: The operation is the same as double-clutching, but it requires neutral be held slightly longer than a single-gear change. Common North American setups include 9, 10, 13, 15, and 18 speeds. Automatic and automated manual transmissions for heavy trucks are becoming more and more common, due to advances both in transmission and engine power. In Europe, 8, 10, 12, and 16 gears are common on larger trucks with
12192-402: The rear wheels securely, while providing decent ride quality . The spring rate (or suspension rate) is a component in setting the vehicle's ride height or its location in the suspension stroke. When a spring is compressed or stretched, the force it exerts, is proportional to its change in length. The spring rate or spring constant of a spring is the change in the force it exerts, divided by
12319-442: The same acceleration and braking performances as a contemporary commercial 32 tractor. Both tractors were brought into production within the newly built "moving line" construction shop, which gave Scammell a modern state-of-the-art factory. The Commander fleet came into operation in 1983. In the late 1970s, Leyland Group decided to develop two new tractors: the overseas bonneted Landtrain ; the UK forward control Roadtrain . Scammell
12446-402: The spring rate. Commonly, springs are mounted on control arms, swing arms or some other pivoting suspension member. Consider the example above, where the spring rate was calculated to be 500 lbs/inch (87.5 N/mm), if one were to move the wheel 1 in (2.5 cm) (without moving the car), the spring more than likely compresses a smaller amount. If the spring moved 0.75 in (19 mm),
12573-438: The sprung center of gravity height (used to calculate the roll moment arm length). Calculating the front and rear sprung weight transfer will also require knowing the roll couple percentage. The roll axis is the line through the front and rear roll centers that the vehicle rolls around during cornering. The distance from this axis to the sprung center of gravity height is the roll moment arm length. The total sprung weight transfer
12700-430: The sprung mass, if the roll center is above ground, or compress it, if underground. Generally, the higher the roll center , the more jacking force is experienced. Travel is the measure of distance from the bottom of the suspension stroke (such as when the vehicle is on a jack, and the wheel hangs freely) to the top of the suspension stroke (such as when the vehicle's wheel can no longer travel in an upward direction toward
12827-420: The three-wheeled Mechanical Horse , designed by Oliver North to replace horses in rail, postal and other delivery applications. This featured automatic carriage coupling and the single front wheel could be steered through 360 degrees. It was sold in three- and six-ton versions. The three-tonner was powered by a 1,125-cc side-valve petrol engine and the six-tonner by a 2,043-cc engine. Karrier had introduced
12954-476: The tire and the road surface, it may hold the road best at a slightly different angle. Small changes in camber, front and rear, can be used to tune handling. Some racecars are tuned with -2 to -7° camber, depending on the type of handling desired, and tire construction. Often, too much camber will result in the decrease of braking performance due to a reduced contact patch size through excessive camber variation in suspension geometry. The amount of camber change in bump
13081-435: The tire's force vector points from the contact patch of the tire through instant center. The larger this component is, the less suspension motion will occur. Theoretically, if the resultant of the vertical load on the tire and the lateral force generated by it points directly into the instant center, the suspension links will not move. In this case, all weight transfer at that end of the vehicle will be geometric in nature. This
13208-413: The travel, the suspension bushings would take all the force, when suspension reaches "full droop", and it can even cause the coil springs to come out of their "buckets", if they are held in by compression forces only. A limiting strap is a simple strap, often from nylon of a predetermined length, that stops downward movement at a pre-set point before theoretical maximum travel is reached. The opposite of this
13335-575: The truck can have on the Interstate highway system. Each State determines the maximum permissible vehicle , combination , and axle weight on state and local roads. Uniquely, the State of Michigan has a gross vehicle weight limit of 164,000 lb (74 t), which is twice the U.S. federal limit. A measure to change the law was defeated in the Michigan Senate in 2019. Almost all trucks share
13462-489: The true driveshaft and exerted the force to its ball joint at the extreme rear of the transmission, which was attached to the engine. A similar method like this was used in the late 1930s by Buick and by Hudson 's bathtub car in 1948, which used helical springs that could not take fore-and-aft thrust. The Hotchkiss drive , invented by Albert Hotchkiss, was the most popular rear suspension system used in American cars from
13589-660: The turn of the 19th century, although the iron chains were replaced with the use of leather straps called thoroughbraces by the 17th century. No modern automobiles have used the thoroughbrace suspension system. By approximately 1750, leaf springs began appearing on certain types of carriage, such as the Landau . By the middle of the 19th century, elliptical springs might additionally start to be used on carriages. Automobiles were initially developed as self-propelled versions of horse-drawn vehicles. However, horse-drawn vehicles had been designed for relatively slow speeds, and their suspension
13716-405: The use of diesel engines in heavy trucks. CNG engines are widely used in the US refuse industry and in concrete mixers, among other short-range vocations, but range limitations have prevented their broader uptake in freight hauling applications. Heavy electric trucks and hydrogen-powered trucks are new to the market in 2021, but major freight haulers are interested. Although cars will be first
13843-430: The vast majority feature body-on-frame construction, with a cabin that is independent of the payload portion of the vehicle. Smaller varieties may be mechanically similar to some automobiles . Commercial trucks can be very large and powerful and may be configured to be mounted with specialized equipment, such as in the case of refuse trucks , fire trucks , concrete mixers , and suction excavators . In American English,
13970-414: The vehicle as a ratio of the vehicle's total roll rate. It is commonly adjusted through the use of anti-roll bars , but can also be changed through the use of different springs. Weight transfer during cornering, acceleration, or braking is usually calculated per individual wheel, and compared with the static weights for the same wheels. The total amount of weight transfer is only affected by four factors:
14097-425: The vehicle do so through the contact patches of the tires . The suspension also protects the vehicle itself and any cargo or luggage from damage and wear. The design of front and rear suspension of a car may be different. An early form of suspension on ox -drawn carts had the platform swing on iron chains attached to the wheeled frame of the carriage. This system remained the basis for most suspension systems until
14224-446: The vehicle from the road. Vehicles that commonly experience suspension loads heavier than normal, have heavy or hard springs, with a spring rate close to the upper limit for that vehicle's weight. This allows the vehicle to perform properly under a heavy load, when control is limited by the inertia of the load. Riding in an empty truck meant for carrying loads can be uncomfortable for passengers, because of its high spring rate relative to
14351-429: The vehicle in a location, such, that the suspension will contact the end of the piston when it nears the upward travel limit. These absorb the impact far more effectively than a solid rubber bump-stop will, essential, because a rubber bump-stop is considered a "last-ditch" emergency insulator for the occasional accidental bottoming of the suspension; it is entirely insufficient to absorb repeated and heavy bottoming, such as
14478-433: The vehicle's components that are not supported by the springs. This includes tires, wheels, brakes, spindles, half the control arm's weight, and other components. These components are then (for calculation purposes) assumed to be connected to a vehicle with zero sprung weight. They are then put through the same dynamic loads. The weight transfer for cornering in the front would be equal to the total unsprung front weight times
14605-408: The vehicle). Bottoming or lifting a wheel can cause serious control problems, or directly cause damage. "Bottoming" can be caused by the suspension, tires, fenders, etc. running out of space to move, or the body or other components of the car hitting the road. Control problems caused by lifting a wheel are less severe, if the wheel lifts when the spring reaches its unloaded shape than they are, if travel
14732-525: The vehicles was on the road 17 hours a day during a 4-month period and on average each vehicle traveled 270 km a day on the desert roads. Most of the 125 British Army Commanders were based in Belgium and Germany, with only a few in the United Kingdom. Truck A truck or lorry is a motor vehicle designed to transport freight , carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but
14859-495: The weight of the vehicle. A race car could also be described as having heavy springs, and would also be uncomfortably bumpy. However, even though we say they both have heavy springs, the actual spring rates for a 2,000 lb (910 kg) racecar and a 10,000 lb (4,500 kg) truck are very different. A luxury car, taxi, or passenger bus would be described as having soft springs, for the comfort of their passengers or driver. Vehicles with worn-out or damaged springs ride lower to
14986-705: Was Léonce Girardot in a Panhard with a time of 12 hours, 15 minutes, and 40 seconds. Coil springs first appeared on a production vehicle in 1906 in the Brush Runabout made by the Brush Motor Company. Today, coil springs are used in most cars. In 1920, Leyland Motors used torsion bars in a suspension system. In 1922, independent front suspension was pioneered on Lancia Lambda , and became more common in mass market cars from 1932. Today, most cars have independent suspension on all four wheels. The part on which pre-1950 springs were supported
15113-527: Was a three-axle version of the Handyman. The Contractor was a 6x4 tractor used by various operators including the Australian Army as a tank transporter or as heavy haulage, usually engineering plant for the Royal Australian Engineers . The Australian military units were configured with 335HP Cummins diesel engines and pneumocyclic gearboxes. While one of the trials vehicles which served in
15240-494: Was also in use. The British Army replaced the Crusader in the late 1990s by a Seddon Atkinson tractor unit with a 40–tonne plant trailer and a specialist tank bridge transporter. Many have seen use in the heavy haulage industry due to their incredibly strong chassis. The special heavy haulage tractor was the Crusader based Samson 8×4 with tridem axles. The military specification vehicles were usually equipped with 15-speed Fuller gearboxes and an 8–tonne capstan winch. The Commander
15367-631: Was available with 5 or 8 horsepower (4 or 6 kW) engines. Another early American truck was built by George Eldridge of Des Moines, Iowa, in 1903. It was powered by an engine with two opposed cylinders, and had a chain drive A 1903 Eldridge truck is displayed at the Iowa 80 Trucking Museum, Walcott, Iowa. Trucks of the era mostly used two-cylinder engines and had a carrying capacity of 1.5 to 2 t (3,300 to 4,400 lb). After World War I, several advances were made: electric starters , and 4, 6, and 8 cylinder engines. Although it had been invented in 1897,
15494-715: Was bought by DAF of the Netherlands . DAF elected to build the S26 DROPS at the Leyland plant in Lancashire , and to close the Watford factory. DAF closed the plant in July 1988. It sold the site for redevelopment, and further sold the rights to manufacture (but not the rights to the name nor the premises) of the S24, Nubian, Crusader, and Commander to Alvis Unipower . They opened a new plant in West Watford, offering ongoing support and spare parts for Scammell vehicles. The Tolpits Lane site
15621-521: Was contracted to develop the Landtrain, which used the same cab and bonnet as the Commander replacement, the S24. Equipped with Cummins NT 350 or 400 engine, the S24 could be specified from 40 tonnes GVW to more than 200 tonnes GTW. Scammell also gained the contract to develop and build the eight-wheeled version of the Roadtrain called the Constructor 8 model. This also allowed Scammell to develop and produce
15748-400: Was fixed directly to the springs which were attached to the axles . Within a decade, most British horse carriages were equipped with springs; wooden springs in the case of light one-horse vehicles to avoid taxation , and steel springs in larger vehicles. These were often made of low-carbon steel and usually took the form of multiple layer leaf springs. Leaf springs have been around since
15875-515: Was introduced as a tank transporter in 1978. Designed in the late 1970s, they replaced the Thornycroft Antars in the British Army beginning with the delivery of the first one on 30 March 1984 followed by others totaling 125 units. The 6×4 units could carry a load of 65 tonnes and were used to transport Challenger I tanks. Used during the Gulf War, they were retired in 2002 and replaced by
16002-409: Was not well suited to the higher speeds permitted by the internal combustion engine. The first workable spring-suspension required advanced metallurgical knowledge and skill, and only became possible with the advent of industrialisation . Obadiah Elliott registered the first patent for a spring-suspension vehicle; each wheel had two durable steel leaf springs on each side and the body of the carriage
16129-548: Was redeveloped into a housing estate, the Vale Industrial Estate, and a business park. Tenants include the Camelot Group . Constructor 6WD Contractor 8X4 S24 6WD S26 6WD S26 8WD The Rigid 6 and Rigid 8, for the number of wheels, were produced from 1937 to 1958. The Showtrac was a short-wheelbase 4x2 ballast tractor , one of the few vehicles ever designed specifically for fairground use. It could be supplied with
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