>>Heavy Truck

Truck

DAF tractor with an auto-transport semi-trailer truck carrying Škoda Octavia cars in Cardiff, Wales

A truck is a vehicle usually used for transporting bulk goods, materials, or equipment. The word "truck" comes from the Greek "trochos", meaning "wheel". In America, the big wheels of wagons were called trucks. When the gasoline-engine driven trucks came into fashion, these were called "motor trucks". Lorry is a British term but is only used for the medium and heavy types (see below), i.e. a van, a pickup or a Jeep would never be regarded as a "lorry". Other languages have loanwords based on these terms, such as the Malay lori and the Mexican Spanish troca (or pickup in northern Mexico).

In Australia and New Zealand a small vehicle with an open back is called a ute (short for "utility vehicle") and the word "truck" is reserved for larger vehicles.

History

A British, 1931-built Sentinel steam lorry.

Steam trucks

Trucks and cars have a common ancestor: the steam-powered fardier Nicolas-Joseph Cugnot built in 1769. However, steam trucks were not common until the mid-1800s. The roads of the time, built for horse and carriages, limited these vehicles to very short hauls, usually from a factory to the nearest railway station. The first semi-trailer appeared in 1881, towed by a De Dion steam tractor. Steam-powered trucks were sold in France and the United States until the eve of World War I,and the beginning of World War II in the United Kingdom.

Internal combustion

In 1895 Karl Benz designed and built the first truck in history using the internal combustion engine. Later that year some of Benz's trucks were modified to become the first bus by the Netphener, the first motorbus company in history. Three years later, in 1898, another internal combustion engine truck was built by Gottlieb Daimler. Other companies, such as Peugeot, Renault and Büssing, also built their own versions. Trucks of the era mostly used two-cylinder engines and had a carrying capacity of 1500 to 2000 kg. In 1904, 700 heavy trucks were built in the United States, 1000 in 1907, 6000 in 1910, and 25000 in 1914.

A Benz truck modified by Netphener company (1895)

After World War I, several advances were made: pneumatic tires replaced the previously common full rubber versions. Electric starters, power brakes, 4, 6, and 8 cylinder engines, closed cabs, and electric lighting followed. The first modern semi-trailer trucks also appeared. Touring car builders such as Ford and Renault entered the heavy truck market.

Diesel engines

Although it had been invented in 1890, the diesel engine was not common in trucks in Europe until the 1930s. In the United States, it took much longer for diesel engines be accepted: gasoline engines were still in use on heavy trucks in the 1970s, while in Europe they had been completely replaced 20 years earlier. They are the most commonly used trucks all over the world.

Legal issues

A road train in Australia.

Commercial trucks in the US pay higher road use taxes on a State level than other road vehicles, and are subject to extensive regulation. A few reasons commercial trucks pay higher road use taxes: they are bigger and heavier than most other vehicles, and cause more wear and tear per hour on roadways; and trucks and their drivers are on the road for more hours per day. UPS vehicles are called 'package cars' in the US, because that exempted them from certain tax-rates. Rules on use taxes differ among jurisdictions.

Most jurisdictions have rules for commercial vehicles, regulating how many hours a driver may be on the clock, how much rest and sleep time is required (e.g., 11hrs driving/14hrs onduty followed by 10hrs off, max of 70hrs/8days or 60hrs/7 days, 34 hr restart ), and many other rules. Violations are often subject to significant penalties. Instruments to track each driver's hours must sometimes be fitted.

Trucks are subject to noise emission requirements (emanating from the U.S. Noise Control Act) in order to protect the public from noise health effects, since trucks contribute disproportionately to roadway noise due to elevated stacks and intense tire and aerodynamic noise characteristics.

The Bridge Law deals with the relation between the gross weight of the truck and the amount of axles and the spacing between axles wheel base the truck has. Each State determines the minimum and maximum permissible weight per axle.

Types of trucks by size

Ultra light trucks

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 chassies for this type of vehicle, while Zap Motors markets a version of their Xebra electric tricycle (licensable in the U.S. as a motorcycle).

Very light trucks

A Piaggio

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 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 {0.66L} displacement). These vehicles are used as on-road utility vehicles in Japan. In the United States, mini trucks are not legal to be licensed or operated on public roads and highways, but they are used in many off-road applications.

These Japanese-made kei trucks, mini trucks, or mini cabs that were manufactured for on-road use are therefore competing with off-road ATVs in the United States. U.S. import regulations require that these mini trucks have a 25 mph speed governor.(The U.S. Government's name for this is a low-speed vehicle or LSV.) 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

• Daihatsu Hijet
• Honda Acty
• Mazda Scrum
• Mitsubishi Minicab
• Subaru Sambar
• Suzuki Carry

Light trucks

Light trucks are car-sized (in the US, no more than 6,300 kg (13,000 lb)) and are used by individuals and businesses alike. In the UK they may not weigh more than 3,500kg. Pickup trucks are pervasive in North America and some regions of Latin America, Asia and Africa, but not so in Europe, where this size of commercial vehicle is most often made as vans.

Medium trucks

Medium trucks are larger than light but smaller than heavy trucks. In the US, they are defined as weighing between 6,300 kg (13,000 lb) and 15,000 kg (33,000 lb). For the UK and the EU the weight is between 3.5 and 7.5 tonnes. Local delivery and public service (dump trucks, garbage trucks and fire-fighting trucks) are normally around this size.

Heavy trucks

Heavy trucks are the largest trucks allowed on the road. They are mostly used for long-haul purposes, often in semi-trailer or B-double configuration.

Road train in Australia

Road damage and wear increase very rapidly with the axle weight. The axle weight is truck weight divided by the number of axles, but the actual axle weight depends on the position of the load over the axles. Also the number of steering axles and the suspension type has influence on the road wear. In many countries with good roads a 6-axle truck may have a maximum weight over 50 tons (50,000 kg). In Australia two or three trailers towed by a tractor truck or even a load carrying tractor (a "three and a half") are linked to make what are called road trains. These are useful in carrying mixed loads or substantial weights using only one driver. They are mostly driven in the outback, due to little congestion of cars, and because of the large turns they make. Owing to the difficulties in operating such vehicles they have special priorities over lighter vehicles.

Off-road trucks

Mining Truck

Highway-legal trucks are sometimes outfitted with off-road features such as a front driving axle and special tires for applications such as logging and construction. Trucks that never use public roads, such as the biggest truck ever, the Liebherr T 282B off-road mining truck, are not constrained by weight limits.

Anatomy of a truck

A russian truck from early 20-s

Almost all trucks share a common construction: they are made of a chassis, a cab, an area for placing cargo or equipment, axles, suspension and wheels, an engine and a drivetrain. Pneumatic, hydraulic, water, and electrical systems may also be identified. They are complex machines. Many also tow one or more trailers or semi-trailers.

Cab

Scania R470 flat nose truck

The cab is an enclosed space where the driver is seated. A sleeper is a compartment attached to the cab where the driver can rest while not driving, sometimes seen in semi-trailer trucks.

There are a few possible cab configurations:

• Cab over engine (COE) or flat nose, where the driver is seated on top of the front axle and the engine. This design is almost ubiquitous in Europe, where overall truck lengths are strictly regulated. They were common in the United States, but lost prominence when permitted length was extended in the early 1980s. To access the engine, the whole cab tilts forward, earning this design the name of tilt-cab. This type of cab is especially suited to the delivery conditions in Europe where many roads follow the layout of much more ancient path and trackways which require the additional turning capability of the cab over engine type.

US truck with long nose and sleeper cab

• Conventional cabs are the most common in North America, and are known in the UK as american cabs. The driver is seated behind the engine, as in most passenger cars or pickup trucks. Conventionals are further divided into large car and aerodynamic designs. A "large car" or "long nose" is a conventional truck with a long (6 to 8 foot (1.8 to 2.4 m) or more) hood. With their very square shapes, these trucks experience a lot of wind resistance and typically consume more fuel. They also provide somewhat poorer visibility than their aerodynamic or COE counterparts. By contrast, Aerodynamic cabs are very streamlined, with a sloped hood and other features to lower drag. Most owner-operators prefer the square-hooded conventionals.
• Cab beside engine designs also exist, but are rather rare.

Engine

Trucks can use all sorts of engines. Small trucks such as SUVs or pickups, and even light medium-duty trucks in North America will use gasoline engines. Most heavier trucks use four stroke turbo intercooler diesel engines, although there are alternatives. Huge off-highway trucks use locomotive-type engines such as a V12 Detroit Diesel two stroke engine.

In the United States, highway trucks almost always use an engine built by a third party, such as CAT, Cummins, or Detroit Diesel. The only exceptions to this are Volvo Trucks and Mack Trucks, which are available with Volvo and Mack diesel engines, respectively, and Freightliner, a subsidiary of DaimlerChrysler, which are available with Mercedes-Benz and Detroit Diesel engines. Trucks and busses built by the Navistar International can also contain International engines. The Swedish truckmaker Scania claims they stay away from the US-market because of this third party tradition. Scania wants to sell a highly integrated product with proven interoperability and quality.

In the European union all truck engines must comply with Euro 4 regulations, the regulations will become more severe in 2008 with the introduction of Euro 5.

Drivetrain

A logging truck

Small trucks use the same type of transmissions as almost all cars which have either an automatic transmission or a manual transmission with synchronisers. Bigger trucks often use manual transmissions without synchronisors which are lighter weight although some synchronised transmissions have been used in larger trucks. Transmissions without synchronisors require either double clutching for each shift, (which can lead to repetitive motion injuries,) or a technique known colloquially as "floating," a method of shifting which doesn't use the clutch, except for starts and stops. Although widely used, due to the tiring nature of double clutching, floating is technically illegal and can not be used on trucks which do not have a tachometer. Common North American setups include 10, 13 and 18 speeds. Automatic and semi-automatic transmissions for heavy trucks are becoming more and more common, due to advances both in transmission and engine power. In Europe 8, 10 and 12 gears are common on larger trucks with manual transmission, while automatic or semiautomatic transmission would have anything from 5 to 12 gears.

The trend in Europe is that more new trucks are being bought with automatic or semi-automatic transmission. This may be due in part to lawsuits from drivers claiming that driving a manual transmission is damaging to their knees.And the fact that you can lower fuel consumption and improve the durability of the truck.

Chassis

A Polish 1936-built Fiat 621 L fire truck in Warsaw, Poland

The chassis or frame of a truck is commonly constructed mainly of two beams, and several crossmembers. A truck chassis consists of two parallel straight C-shaped beams, or in some cases stepped or tapered beams, these held together by crossmembers. In most instances, gussets help attach the crossmembers to the beams. The "C-shape" of the beams has a middle vertical and longer side, and a short horizontal flange at each end; the length of the beams is variable. The chassis is usually made of steel, but can be made (whole or in part) of aluminium for a lighter weight. The integrity of the chemical composition (carbon, molybdenum, etc.) and structure of the beams is of uttermost importance to its strength, and to help prevent cracking or breaking of beams, and to help maintain rigidity and flexibility of the frame, welding, drilling and other types of modifications should not be performed by unlicenced persons. The chassis is the main structure of the truck, and the other parts attach to it. A tow bar may be found attached at one or both ends.

Environmental effects

Trucks contribute to air, noise and water pollution in a similar fashion to automobiles. In fact, in the case of air pollution emissions, trucks may actually emit lower emissions than autos on a per pound of vehicle mass basis, although the absolute level on a vehicle mile traveled basis is higher. With respect to noise pollution trucks emit considerably higher sound levels at all speeds compared to typical automobiles; this contrast is particlarly strong in the case of heavy duty trucks.

Concerns have been raised about the effect of trucking on the environment, particularly as part of the debate on global warming. In the period from 1990 to 2003, carbon dioxide emissions from transportation sources increased by 20%, despite improvements in vehicle fuel efficiency.

In 2005, Transportation accounted for 27% of U.S. greenhouse gas emission, increasing faster than any other sector .

Between 1985 and 2004, in the US, energy consumption in freight transportation grew nearly 53%, while the number of ton-miles carried increased only 43%. "Modal shifts account for a nearly a 23% increase in energy consumption over this period. Much of this shift is due to a greater fraction of freight ton-miles being carried via truck and air, as compared to water, rail, and pipelines."

According to a 1995 US Government estimate, the energy cost of carrying a ton of freight a distance of one mile averages 514 Btu for water, 337 Btu for rail, 3,100 for trucks and nearly 20,000 for air transport. and many environment organizations favor laws and incentives to encourage the switch from road to rail, especially in Europe .