A semi-trailer truck (more commonly semi truck or simply "semi") is the combination of a tractor unit and one or more semi-trailers to carry freight. A semi-trailer attaches to the tractor with a fifth-wheel coupling (hitch), with much of its weight borne by the tractor. The result is that both the tractor and semi-trailer will have a distinctly different design than a rigid truck and trailer.
It is variously known as a transport in Canada; semi or single in Australia and New Zealand; semi, tractor-trailer, big rig, or eighteen-wheeler in the United States; and articulated lorry, abbreviated artic, in the United Kingdom, Ireland and New Zealand.
These vehicles have been criticised on safety grounds, including when a study in London found that they caused a disproportionate number of annual cyclist casualties.[1]
Regional configurations
North America

In North America, the combination vehicles made up of a powered truck and one or more semitrailers are known as "semis", "semitrailers",[2] "tractor-trailers", "big rigs", "semi trucks", "eighteen-wheelers", or "semi-tractor trailers".
The tractor unit typically has two or three axles; those built for hauling heavy-duty commercial-construction machinery may have as many as five, some often being lift axles.
The most common tractor-cab layout has a forward engine, one steering axle, and two drive axles. The fifth-wheel trailer coupling on most tractor trucks is movable fore and aft, to allow adjustment in the weight distribution over its rear axle(s).
Ubiquitous in Europe, but less common in North America since the 1990s, is the cabover engine configuration, where the driver sits next to, or over the engine. With changes in the US to the maximum length of the combined vehicle, the cabover was largely phased out of North American over-the-road (long-haul) service by 2007. Cabovers were difficult to service; for a long time the cab could not be lifted on its hinges to a full 90-degree forward tilt, severely limiting access to the front part of the engine.
As of 2016, a truck can cost US$100,000, while the diesel fuel cost can be $70,000 per year.[3] Trucks average from 4 to 8 miles per US gallon (59 to 29L/100km), with fuel economy standards requiring better than 7 miles per US gallon (34L/100km) efficiency by 2014.[4] Power requirements in standard conditions are 170hp at 55mph (89km/h) or 280hp at 70mph (113km/h), and somewhat different power usage in other conditions.[5]

The cargo trailer usually has tandem axles at the rear, each of which has dual wheels, or eight tires on the trailer, four per axle. In the US it is common to refer to the number of wheel hubs, rather than the number of tires; an axle can have either single or dual tires with no legal difference.[6][7] The combination of eight tires on the trailer and ten tires on the tractor is what led to the moniker eighteen wheeler, although this term is considered by some truckers to be a misnomer (the term "eighteen-wheeler" is a nickname for a five-axle over-the-road combination). Many trailers are equipped with movable tandem axles to allow adjusting the weight distribution.
To connect the second of a set of doubles to the first trailer, and to support the front half of the second trailer, a converter gear known as a "dolly" is used. This has one or two axles, a fifth-wheel coupling for the rear trailer, and a tongue with a ring-hitch coupling for the forward trailer. Individual states may further allow longer vehicles, known as "longer combination vehicles" (or LCVs), and may allow them to operate on roads other than Interstates.
Long combination vehicle types include:
Doubles (officially "STAA doubles", known colloquially as "a set of joints"): Two 28.5ft (8.7m) trailers.
Triples: Three 28.5ft (8.7m) trailers.
Turnpike Doubles: Two 48ft (14.6m) trailers.
Rocky Mountain Doubles: One 40 to 53ft (12.2 to 16.2m) trailer (though usually no more than 48ft (14.6m)) and one 28.5ft (8.7m) trailer (known as a "pup").
In Canada, a Turnpike Double is two 53ft (16.2m) trailers, and a Rocky Mountain Double is a 50ft (15.2m) trailer with a 24ft (7.3m) "pup".
Future long combination vehicles under consideration and study for the U.S. MAP-21 transportation bill are container doubles. These combinations are under study for potential recommendation in November 2014:
40ft (12m) trailer Turnpike Doubles, 148,000lb (67,000kg) GVWR
40ft (12m) and 20ft (6.1m) trailer Rocky Mountain Doubles, 134,000lb (61,000kg) GVWR
Double 20ft (6.1m) trailers.
The US federal government, which only regulates the Interstate Highway System, does not set maximum length requirements (except on auto and boat transporters), only minimums. Tractors can pull two or three trailers if the combination is legal in that state. Weight maximums are 20,000lb (9,100kg) on a single axle, 34,000lb (15,000kg) on a tandem, and 80,000lb (36,000kg) total for any vehicle or combination. There is a maximum width of 8.5ft (2.6m) and no maximum height.[8][9]
Roads other than the Interstates are regulated by the individual states, and laws vary widely. Maximum weight varies between 80,000lb (36,000kg) to 171,000lb (78,000kg), depending on the combination.[10] Most states restrict operation of larger tandem trailer setups such as triple units, turnpike doubles and Rocky-Mountain doubles. Reasons for limiting the legal trailer configurations include both safety concerns and the impracticality of designing and constructing roads that can accommodate the larger wheelbase of these vehicles and the larger minimum turning radii associated with them. In general, these configurations are restricted to the Interstates. Except for these units, double setups are not restricted to certain roads any more than a single setup. They are also not restricted by weather conditions or "difficulty of operation".  The Canadian province of Ontario, however, does have weather-related operating restrictions for larger tandem trailer setups.[11]
Europe

The noticeable difference between tractor units in Europe and North America is that almost all European models are cab over engine (called "forward control" in England[12]), while the majority of North American trucks are "conventional" (called "normal control" or "bonneted" in England[13]).[14]  European trucks, whether straight trucks or fully articulated, have a sheer face on the front. This allows shorter trucks with longer trailers (with larger freight capacity) within the legal maximum total length. Furthermore, it offers greater maneuverability in confined areas, a more balanced weight-distribution and better overall view for the driver. The major disadvantage is that for repairs on COE trucks, the entire cab has to hinge forward to allow maintenance access. Conversely, "conventional" cab tractors offer the driver a more comfortable driving environment, easier access getting in or out and better protection in a collision.
In Europe usually both rear tractor axles have dual wheels, while single or dual wheels are used for the cargo trailer. The most common combination used in Europe is a semi tractor with three axles, one a lift axle, and a cargo trailer with three axles, one also a lift axle, giving six axles and 22 wheels in total. This format is now common across Europe, due to reduced road-loading requirements, especially for bridges. The lift axles used on both tractors and trailers allow the trucks to remain legal, but increases maneuverability  while at the same time reducing fuel consumption and tyre wear when carrying lighter loads, by raising one or multiple axle set(s) off the roadway. Although lift axles usually operate automatically, they can be lowered manually even while carrying light loads, in order to remain within legal (safe) limits when, for example, navigating back-road bridges with severely restricted axle loads. For greater detail, see the United Kingdom section, below.
When using a dolly, which generally has to be equipped with lights and a license plate, rigid trucks can be used to pull semi-trailers. The dolly is equipped with a fifth wheel to which the trailer is coupled. Because the dolly attaches to a pintle hitch on the truck, maneuvering a trailer hooked to a dolly is different from maneuvering a fifth wheel trailer. Backing the vehicle requires same technique as backing an ordinary truck/full trailer combination, though the dolly/semi setup is probably longer, thus requiring more space for maneuvering. The tractor/semi-trailer configuration is rarely used on timber trucks, since these will use the two big advantages of having the weight of the load on the drive wheels, and the loader crane used to lift the logs from the ground can be mounted on the rear of the truck behind the load, allowing a short (lightweight) crane to reach both ends of the vehicle without uncoupling. Also construction trucks are more often seen in a rigid + midaxle trailer configuration instead of the tractor/semi-trailer setup.
United Kingdom

In the United Kingdom, the maximum permitted gross weight of a semi-trailer truck, without the use of a Special Type General Order (STGO), is 97,000lb (44t). In order for a 97,000lb semi-trailer truck to be permitted on UK roads the tractor and semi-trailer must have three or more axles each. Lower weight semi-trailer trucks can mean some tractors and trailer having fewer axles.[15] In practice, like double decker buses and coaches in the UK, there is no legal height limit for semi-trailer trucks; however, bridges over 16.5ft (5.03m) do not have the height marked on them. Semi-trailer trucks on Continental Europe have a height limit of 13.1ft (4.0m).
Vehicles heavier than 97,000lb are permitted on UK roads but are indivisible loads, which would be classed as abnormal (or oversize). Such vehicles are required to display an STGO (Special Types General Order) plate on the front of the tractor unit and, under certain circumstances, are required to travel by an authorized route and have an escort.
Most UK trailers are 45ft (13.7m) long and, dependent on the position of the fifth wheel and kingpin, a coupled tractor unit and trailer will have a combined length of between 50 and 55ft (15.25 and 16.75m). Although the Construction and Use Regulations allow a maximum rigid length of 60ft (18.2m), this, combined with a shallow kingpin and fifth wheel set close to the rear of the tractor unit, can give an overall length of around 75ft (22.75m).[16]
Starting in January 2012 the Department for Transport is conducting a trial of longer semi-trailers. The trial involves 900 semi-trailers of 48ft (14.6m) in length (i.e. 3ft (1m) longer than the current maximum), and a further 900 semi-trailers of 51ft (15.65m) in length (i.e. 7ft (2.05m) longer). This will result in the total maximum length of the semi-trailer truck being 57ft (17.5m) for trailers 48ft in length, and 61ft (18.55m) for trailers 51ft long. The increase in length will not result in the 97,000lb weight limit being exceeded and will allow some operators to approach the weight limit which may not have been previously possible due to the previous length of trailers. The trial will run for a maximum of 10 years. Providing certain requirements are fulfilled, a Special Types General Order (STGO) allows for vehicles of any size or weight to travel on UK roads. However, in practice any such vehicle has to travel by a route authorized by the Department of Transport and move under escort. The escort of abnormal loads in the UK is now predominantly carried out by private companies, but extremely large or heavy loads that require road closures must still be escorted by the police.
In the UK, some semi-trailer trucks have eight tires on three axles on the tractor; these are known as six-wheelers or "six leggers", with either the center or rear axle having single wheels which normally steer as well as the front axle and can be raised when not needed (i.e. when unloaded or only a light load is being carried; an arrangement known as a TAG axle when it is the rear axle, or mid-lift when it is the center axle).  Some trailers have two axles which have twin tires on each axle; other trailers have three axles, of which one axle can be a lift axle which has super-single wheels. In the UK, two wheels bolted to the same hub are classed as a single wheel, therefore a standard six-axle articulated truck is considered to have twelve wheels, even though it has twenty tires. The UK also allows semi-trailer truck which have six tires on two axles; these are known as four-wheelers.

In 2009, the operator Denby Transport designed and built a 83ft  long (25.25m) B-Train (or B-Double) semi-trailer truck called the Denby Eco-Link to show the benefits of such a vehicle, which were a reduction in road accidents and result in less road deaths, a reduction in emissions due to the one tractor unit still being used and no further highway investment being required. Furthermore, Denby Transport asserted that two Eco-Links would replace three standard semi-trailer trucks while, if limited to the current UK weight limit of 97,000lb, it was claimed the Eco-Link would reduce carbon emissions by 16% and could still halve the number of trips needed for the same amount of cargo carried in conventional semi-trailer trucks. This is based on the fact that for light but bulky goods such as toilet paper, plastic bottles, cereals and aluminum cans, conventional semi-trailer trucks run out of cargo space before they reach the weight limit. At 97,000lb, as opposed to 132,000lb usually associated with B-Trains, the Eco-Link also exerts less weight per axle on the road compared to the standard six-axle 97,000lb semi-trailer truck.
The vehicle was built after Denby Transport believed they had found a legal-loophole in the present UK law to allow the Eco-Link to be used on the public roads. The relevant legislation concerned the 1986 Road Vehicles Construction and Use Regulations. The 1986 regulations state that "certain vehicles" may be permitted to draw more than one trailer and can be up to 85ft (25.9m). The point of law reportedly hinged on the definition of a "towing implement", with Denby prepared to argue that the second trailer on the Eco-Link was one. The Department for Transport were of the opinion that this refers to recovering a vehicle after an accident or breakdown, but the regulation does not explicitly state this.
During BTAC performance testing the Eco-Link was given an "excellent" rating for its performance in maneuverability, productivity, safety and emissions tests, superseding ordinary semi-trailer trucks in many respects. Private trials had also reportedly shown the Denby vehicle had a 20% shorter stopping distance than conventional semi-trailer trucks of the same weight, due to having extra axles. The active steer system meant that the Eco-Link had a turning circle of 41ft (12.5m), the same as a conventional semi-trailer truck.
Although the Department for Transport advised that the Eco-Link was not permissible on public roads, Denby Transport gave the Police prior warning of the timing and route of the test drive on the public highway, as well as outlining their position in writing to the Eastern Traffic Area Office. On 1 December 2009 Denby Transport were preparing to drive the Eco-Link on public roads, but this was cut short because the Police pulled the semi-trailer truck over as it left the gates in order to test it for its legality "to investigate any... offenses which may be found". The Police said the vehicle was unlawful due to its length and Denby Transport was served with a notice by the Vehicle and Operator Services Agency (VOSA) inspector to remove the vehicle from the road for inspection. Having returned to the yard, Denby Transport was formally notified by Police and VOSA that the semi-trailer truck could not be used. Neither the Eco-Link, nor any other B-Train, have since been permitted on UK roads. However, this prompted the Department for Transport to undertake a desk study into semi-trailer trucks, which has resulted in the longer semi-trailer trial which commenced in 2012.
Continental Europe

The maximum overall length in the EU and EEA member states was 18.75m (61.5ft) with a maximum weight of 40tonnes, or 44tonnes if carrying an ISO container.[17] However, rules limiting the semi-trailers to 16.5m (54ft) and 18.75m are met with trucks carrying a standardized 7.82m (26ft) body with one additional 7.82m body on tow as a trailer.[18] 25.25metre truck combinations were developed under the branding of EcoCombi which influenced the name of EuroCombi for an ongoing standardization effort where such truck combinations shall be legal to operate in all jurisdictions of the European Economic Area. With the 50% increase in cargo weight, the fuel efficiency increases with an average of 20% with a corresponding relative decrease in carbon emissions and with the added benefit of one third fewer trucks on the road.[17] The 1996 EU regulation defines a Europe Module System (EMS) as it was implemented in Sweden. The wording of EMS combinations and EuroCombi are now used interchangeably to point to truck combinations as specified in the EU document; however, apart from Sweden and Finland, the EuroCombi is only allowed to operate on specific tracks in other EU member states.  Since 1996, when Sweden and Finland formally won a final exemption from the European Economic Area rules with 60tonne and 25.25m (83ft) combinations, all other From 2006, 25.25m truck trailer combinations are to be allowed on restricted routes within Germany, following a similar (on-going) trial in The Netherlands. Similarly, Denmark has allowed 25.25m combinations on select routes. These vehicles will run a 60tonne weight limit. Two types are to be used: 1) a 26-tonne truck pulling a dolly and semi-trailer, or 2) an articulated tractor unit pulling a B-double, member states gained the ability to adopt the same rules. In Italy the maximum permitted weight (unless exceptional transport is authorized) is 44 tonnes for any kind of combination with five axles or more.
The tractor/semi-trailer configuration is rarely used on timber trucks, since these will use the two big advantages of having the weight of the load on the drive wheels, and the loader crane used to lift the logs from the ground can be mounted on the rear of the truck behind the load, allowing a short (lightweight) crane to reach both ends of the vehicle without uncoupling. Also construction trucks are more often seen in a rigid + midaxle trailer configuration instead of the tractor/semi-trailer setup.
Scandinavia

Denmark and Norway allow 25.25m (83ft) trucks (Denmark from 2008, and Norway from 2008 on selected routes). In Sweden the allowed length has been 24m (79ft) since 1967. Before that, the maximum length was unlimited; the only limitations were on axle load. What stopped Sweden from adopting the same rules as the rest of Europe, when securing road safety, was the national importance of a competitive forestry industry.[17][19] Finland, with the same road safety issues and equally important forestry industry, followed suit. The change made trucks able to carry three stacks of cut-to-length logs instead of two, as it would be in a short combination. They have one on stack together with a crane on the 6×4 truck, and two additional stacks on a four axle trailer. The allowed gross weight in both countries is up to 60 tonnes depending on the distance between the first and last axle.
In the negotiations starting in the late 1980s preceding Sweden and Finland's entries to the European Economic Area and later the European Union, they insisted on exemptions from the EU rules citing environmental concerns and the transportation needs of the logging industry. In 1995, after their entry to the union, the rules changed again, this time to allow trucks carrying a standard CEN unit of 7.82m (26ft) to draw a 13.6m (45ft) standard semi-trailer on a dolly, a total overall length of 25.25m. Later, B-double combinations came into use, often with one 6m (20ft) container on the B-link and a 12m (40ft) container (or two 6m containers) on a semi-trailer bed. In allowing the longer truck combinations, what would take two 16.5m (54ft) semi-trailer trucks and one 18.75m (62ft) truck and trailer to haul on the continent now could be handled by just two 25.25m trucks – greatly reducing overall costs and emissions. Prepared since late 2012 and effective on January 2013, Finland has changed its regulations to allow total maximum legal weight of a combination to be 76tonnes. At the same time the maximum allowed height would be increased by 20cm (8in); from current maximum of 4.2m (13.8ft) to 4.4m (14.4ft). The effect this major maximum weight increase would cause to the roads and bridges in Finland over time is strongly debated.
However, longer and heavier combinations are regularly seen on public roads; special permits are issued for special cargo. The mining company Boliden AB have a standing special permit for 80tonne combinations on select routes between mines in the inland and the processing plant in Boliden, taking a 50tonne load of ore. Volvo has a special permit for a 32m (105ft), steering B-trailer-trailer combination carrying two 12m (40ft) containers to and from Gothenburg harbour and the Volvo Trucks factory, all on the island of Hisingen.[20] Another example is the ongoing project En Trave Till (lit. One more pile/stack) started in December 2008. It will allow even longer vehicles to further rationalize the logging transports. As the name of the project points out, it will be able to carry four stacks of timber, instead of the usual three. The test is limited to Norrbotten county and the European route E4 between the timber terminal in Överkalix and the sawmill in Munksund (outside Piteå). The vehicle is a 30m (98ft) long truck trailer combination with a gross weight exceeding 90tonnes. It is estimated that this will give a 20% lower cost and 20-25% CO2 emissions reduction compared to the regular 60tonne truck combinations. As the combinations spreads its weight over more axles, braking distance, road wear and traffic safety is believed to be either the same or improved with the 90tonne truck-trailer. In the same program two types of 74tonne combinations will be tested in Dalsland and Bohuslän counties in western Sweden: an enhanced truck and trailer combination for use in the forest and a b-double for plain highway transportation to the mill in Skoghall. In 2012, the Northland Mining company received permission for 90tonne combinations with normal axle load (an extra dolly) for use on the 150km (93mi) Kaunisvaara-Svappavaara route, carrying iron ore.[21][22][23]
As of 2015, the longest and heaviest truck in everyday use in Finland is operated by transport company Ketosen Kuljetus as part of a pilot project studying transport efficiency in the timber industry. The combined vehicle is 33-metre (108ft) long, has 13 axles, and weighs a total of 104 tonnes (229,000lb).[24][25]
Starting from Jan 21 2019 Finland Government change the maximum allowed length of truck from 25,25 meters to 34,50 meters. New types of vehicle combinations that differ from the current standards may also be used on the road. The requirements for combinations also include camera systems for side visibility, an advanced emergency braking and lane detector system, electronic driving stability system and electronically controlled brakes.
Australasia
Australia

Australian road transport has a reputation for using very large trucks and road trains. This is reflected in the most popular configurations of trucks generally having dual drive axles and three axles on the trailers, with four tyres on each axle. This means that Australian single semi-trailer trucks will usually have 22 tyres, which is generally more than their counterparts in other countries. Super single tyres are sometimes used on tri-axle trailers. The suspension is designed with travel limiting, which will hold the rim off the road for one blown or deflated tyre for each side of the trailer, so a trailer can be driven at reduced speed to a safe place for repair. Super singles are also often used on the steer axle in Australia to allow greater loading over the steer axle. The increase in loading of steer tyres requires a permit.
Long haul transport usually operates as B-doubles with two trailers (each with three axles), for a total of nine axles (including steering). In some lighter duty applications only one of the rear axles of the truck is driven, and the trailer may have only two axles. From July 2007, the Australian Federal and State Governments allowed the introduction of B-triple trucks on a specified network of roads.[26] B-Triples are set up differently from conventional road trains. The front of their first trailer is supported by the turntable on the prime mover. The second and third trailers are supported by turntables on the trailers in front of them. As a result, B-Triples are much more stable than road trains and handle exceptionally well. True road trains only operate in remote areas, regulated by each state or territory government.
In total, the maximum length that any articulated vehicle may be (without a special permit and escort) is 53.5m (176ft), its maximum load may be up to 164tonnes gross, and may have up to four trailers. However, heavy restrictions apply to the areas where such a vehicle may travel in most states. In remote areas such as the Northern Territory great care must be taken when sharing the road with longer articulated vehicles that often travel during the daytime, especially four-trailer road trains.
Articulated trucks towing a single trailer or two trailers (commonly known as "short doubles") with a maximum overall length of 19m (62ft) are referred to as "General access heavy vehicles" and are permitted in all areas, including metropolitan. B-doubles are limited to a maximum total weight of 62.5tonnes and overall length of 25m (82ft), or 26m (85ft) if they are fitted with approved FUPS (Front Underrun Protection System) devices. B-doubles may only operate on designated roads, which includes most highways and some major metropolitan roads. B-doubles are very common in all parts of Australia including state capitals and on major routes they outnumber single trailer configurations.
Maximum width of any vehicle is 2.5m (8.2ft) and a height of 4.3m (14ft). In the past few years, allowance has been made by several states to allow certain designs of heavy vehicles up to 4.6m (15ft) high but they are also restricted to designated routes. In effect, a 4.6meter high B-double will have to follow two sets of rules: they may access only those roads that are permitted for B-doubles and for 4.6meter high vehicles.
In Australia, both conventional prime movers and cabovers are common, however, cabovers are most often seen on B-doubles on the eastern seaboard where the reduction in total length allows the vehicle to pull longer trailers and thus more cargo than it would otherwise.

An Australian prime mover Kenworth and B double trailer combination
A road train in Australia
B-double truck on the Sturt Highway

New Zealand
New Zealand's legislation governing truck dimensions falls under the Vehicle Dimensions and Mass Rules published by NZ Transport Agency.[27] New rules were introduced effective 1 February 2017.[28] which increased the maximum height, width and weight of loads and vehicles to simplify regulations, increase the amount of freight carried and to improve the range of vehicles and trailers available to transport operators.
Common combinations in New Zealand consist of a standard semi-trailer, a B-double or a rigid towing vehicle pulling a trailer with a drawbar. Standard maximum vehicle lengths for trailers with one axle set are:
Semi-trailer: 19m (62ft)
Simple: 22m (72ft)
Pole: 20m (66ft)
Trailers with two axle sets can be 20m (66ft), including heavy rigid vehicles towing two trailers.
Oversized loads require, at minimum, a permit, and may require a pilot vehicle.[29]
Construction

Types of trailers

There are many types of semi-trailers in use, designed to haul a wide range of products.

Box, or dry van
Bus
Container
Refrigerator, or "reefer"
Tanker
Dry bulk
Flatbed
Lowboy
Car hauler
Dump

Coupling and uncoupling
The cargo trailer is, by means of a king pin, hooked to a horseshoe-shaped quick-release coupling device called a fifth wheel or a turntable hitch at the rear of the towing engine that allows easy hook up and release. The truck trailer cannot move by itself because it only has wheels at the rear end: it requires a forward axle, provided by the towing engine, to carry half the load weight.  When braking hard at high speeds, the vehicle has a tendency to fold at the pivot point between the towing vehicle and the trailer. Such a truck accident is called a "trailer swing", although it is also commonly described as a "jackknife".[30] Jackknifing is a condition where the tractive unit swings round against the trailer, and not vice versa.
Braking

Semi trucks use air pressure, rather than hydraulic fluid, to actuate the brake. The use of air hoses allows for ease of coupling and uncoupling of trailers from the tractor unit. The most common failure is brake fade, usually caused when the drums or discs and the linings of the brakes overheat from excessive use.
The parking brake of the tractor unit and the emergency brake of the trailer are spring brakes that require air pressure in order to be released. They are applied when air pressure is released from the system, and disengaged when air pressure is supplied. This is a fail-safe design feature which ensures that if air pressure to either unit is lost, the vehicle will stop to a grinding halt, instead of continuing without brakes and becoming uncontrollable. The trailer controls are coupled to the tractor through two gladhand connectors, which provide air pressure, and an electrical cable, which provides power to the lights and any specialized features of the trailer.
Glad-hand connectors (also known as palm couplings) are air hose connectors, each of which has a flat engaging face and retaining tabs. The faces are placed together, and the units are rotated so that the tabs engage each other to hold the connectors together. This arrangement provides a secure connection but allows the couplers to break away without damaging the equipment if they are pulled, as may happen when the tractor and trailer are separated without first uncoupling the air lines. These connectors are similar in design to the ones used for a similar purpose between railroad cars. Two air lines typically connect to the trailer unit. An emergency or main air supply line pressurizes the trailer's air tank and disengages the emergency brake, and a second service line controls the brake application during normal operation.
In the UK, male/female quick release connectors (red line or emergency), have a female on the truck and male on the trailer,  but a yellow line or service has a male on the truck and female on the trailer. This avoids coupling errors (causing no brakes) plus the connections will not come apart if pulled by accident. The three electrical lines will fit one way around a primary black, a secondary green, and an ABS lead, all of which are collectively known as suzies or suzie coils.
Another braking feature of semi-trucks is engine braking, which could be either a compression brake (usually shortened to Jake brake) or exhaust brake or combination of both. However, the use of compression brake alone produces a loud and distinctive noise, and to control noise pollution, some local municipalities have prohibited or restricted the use of engine brake systems inside their jurisdictions, particularly in residential areas. The advantage to using engine braking instead of conventional brakes is that a truck can descend a long grade without overheating its wheel brakes. Some vehicles can also be equipped with hydraulic or electric retarders which have an advantage of near silent operation.
Transmission

Because of the wide variety of loads the semi may carry, they usually have a manual transmission to allow the driver to have as much control as possible. However, all truck manufacturers now offer semi-automatic transmissions (manual gearboxes with automated gear change), as well as automatic transmissions.
Semi-truck transmissions can have as few as three forward speeds or as many as 18 forward speeds (plus 2 reverse speeds). A large number of transmission ratios means the driver can operate the engine more efficiently. Modern on-highway diesel engines are designed to provide maximum torque in a narrow RPM range (usually 1200-1500 RPM); having more gear ratios means the driver can hold the engine in its optimum range regardless of road speed (drive axle ratio must also be considered).
A ten-speed manual transmission, for example is controlled via a six-slot H-box pattern, similar to that in five-speed cars — five forward and one reverse gear. Gears six to ten (and high speed reverse) are accessed by a Lo/High range splitter; gears one to five are Lo range; gears six to ten are High range using the same shift pattern. A Super-10 transmission, by contrast, has no range splitter; it uses alternating "stick and button" shifting (stick shifts 1-3-5-7-9, button shifts 2-4-6-8-10).  The 13-, 15-, and 18-speed transmissions have the same basic shift pattern, but include a splitter button to enable additional ratios found in each range. Some transmissions may have 12 speeds.
Another difference between semi-trucks and cars is the way the clutch is set up. On an automobile, the clutch pedal is depressed full stroke to the floor for every gear shift, to ensure the gearbox is disengaged from the engine. On a semi-truck with constant mesh transmission (non synchronized), such as by the Eaton Roadranger series, not only is double clutching required, but a clutch brake is required as well. The clutch brake stops the rotation of the gears, and allows the truck to be put into gear without grinding when stationary. The clutch is pressed to the floor only to allow smooth engagement of low gears when starting from a full stop; when the truck is moving, the clutch pedal is pressed only far enough to break torque for gear changes.
Lights
An electrical connection is made between the tractor and the trailer through a cable often referred to as a pigtail. This cable is a bundle of wires in a single casing. Each wire controls one of the electrical circuits on the trailer, such as running lights, brake lights, turn signals, etc. A straight cable would break when the rig went around corners, so a coiled cable is used which retracts these coils when not under tension. It is these coils that cause the cable to look like a pigtail.
In most countries, a trailer or semi-trailer must have minimum
2 rear lights (red)
2 stop lights (red)
2 turning lights; one for right and one for left, flashing (amber; red optional in North America)
2 marking lights behind if wider than certain specifications (red; plus a group of 3 red lights in the middle in North America)
2 marking lights front if wider than the truck or wider than certain specifications (white; amber in North America)
Wheels and tires
Although dual wheels are the most common, use of two single, wider tires, known as super singles, on each axle is becoming popular among bulk cargo carriers and other weight-sensitive operators. With increased efforts to reduce greenhouse gas emissions, the use of the super-single tire is gaining popularity. There are several advantages to this configuration. The first of these is that super singles reduce fuel consumption. In 1999, tests on an oval track showed a 10% fuel savings when super singles were used. These savings are realized because less energy is wasted flexing fewer tire sidewalls. Second, the lighter overall tire weight allows a truck to be loaded with more freight. The third advantage is that the single wheel encloses less of the brake unit, which allows faster cooling and reduces brake fade.
One of the major disadvantages of the super singles is that they are currently not as widely available as a standard tire. In addition, if a tire should become deflated or be destroyed, there is not another tire attached to the same hub to maintain the dynamic stability of the vehicle, as would be the case with dual wheels. With dual wheels, the remaining tire may be overloaded, but it will typically allow the vehicle to be safely stopped or driven to a repair facility.
In Europe, super singles became popular when the allowed weight of semitrailer rigs was increased from 38 to 40 tonnes.[31] In this reform the trailer industry replaced two 10-tonne (22,000lb) axles with dual wheels, with three 8-tonne (18,000lb) axles on wide-base single wheels. The significantly lower axle weight on super singles must be considered when comparing road wear from single versus dual wheels. The majority of super singles sold in Europe have a width of 385mm (15.2in). The standard 385 tires have a legal load limit of 4,500kg (9,900lb). (Note that expensive, specially reinforced 385 tires approved for 5,000kg (11,000lb) do exist. Their market share is tiny, except for mounting on the steer axle.)
Skirted trailers

An innovation rapidly growing in popularity is the skirted trailer. The space between the road and the bottom of the trailer frame was traditionally left open until it was realized that the turbulent air swirling under the trailer is a major source of aerodynamic drag. Three split skirt concepts were verified by the United States Environmental Protection Agency (EPA) to provide fuel savings greater than 5%, and four split skirt concepts had EPA-verified fuel savings between 4% and 5%.[32]
Skirted trailers are often combined with Underrun Protection Systems (underride guards), greatly improving safety for passenger vehicles sharing the road.
Underride guard

Technically called a Rear Underrun Protection System (RUPS), this is a rigid assembly hanging down from the bottom rear of the trailer, which is intended to provide some protection for passenger cars which collide with the rear of the trailer. Public awareness of this safeguard was increased in the aftermath of the accident that killed actress Jayne Mansfield on 29 June 1967, when the car she was in hit the rear of a tractor-trailer, causing fatal head trauma. After her death, the NHTSA recommended requiring a rear underride guard, also known as a Mansfield bar, an ICC bar, or a DOT bumper,[33][34]. In Europe, side and rear underrun protection are mandated on all lorries and trailers with a gross weight of 3,500kg or more.[35]
The bottom rear of the trailer is near head level for an adult seated in a car, and without the underride guard, the only protection for such an adult's head in a rear-end collision would be the car's windshield. The front of the car goes under the platform of the trailer rather than making contact via the passenger car bumper, so the car's protective crush zone becomes irrelevant and air bags are ineffective in protecting the car passengers. The underride guard provides a rigid area for the car to contact at the height of its bumper.
In addition to rear underride guards, truck tractor cabs may be equipped with a Front Underrun Protection System (FUPS) at the front bumper of the truck, if the front end is not low enough for the bumper to provide the adequate protection on its own.  The safest tractor-trailers are also equipped with side underride guards, also called Side Underrun Protection System (SUPS). These additional barriers prevent passenger cars from skidding underneath the trailer from the side, such as in an oblique or side collision, or if the trailer jackknifes across the road.  In addition to safety benefits, these underride guards may improve fuel mileage by reducing air turbulence under the trailer at highway speeds.
Another benefit of having a sturdy underride guard is that it may be secured to a loading dock with a hook to prevent "trailer creep", a movement of the trailer away from the dock, which opens up a dangerous gap during loading or unloading operations.[36]
Semi-truck manufacturers
Current semi-truck manufacturers include:
United States and Canada

Caterpillar
Crane Carrier Company
Ford
Freightliner
Hino Motors (Canadian plant)
Kenworth
Mack
Navistar International
Oshkosh
Peterbilt
Tesla
Volvo
Western Star

Europe

ADR Group Trailer
DAF Trucks
Iveco
Kamaz
KrAZ
MAN
MAZ
Mercedes-Benz
Renault Trucks
Scania
Sisu
Tatra
Volvo
ZiL

Asia/Pacific

Asia MotorWorks
C&C Trucks (China)
CAMC Star (China)
China National Heavy Duty Truck Group
FAW Group (China)
Foton Motor (China)
Hino Motors
Hyundai
Isuzu
Mahindra Truck and Bus Division
Mitsubishi Fuso Truck and Bus Corporation
Tata Daewoo
Tata Motors
UD Trucks

Other locations

Al Kowary Industries (Bahrain)
Ashok Leyland (India)
BharatBenz (India)
BMC (Turkey)
Eicher Motors (India)
Volkswagen Caminhões e Ônibus (Latin America, South Africa)

Driver's license

A special driver's license is required to operate various commercial vehicles.
Canada
Regulations vary by province. A license to operate a vehicle with air brakes is required (i.e., normally a Class I, II, or III commercial license with an "A" or "S" endorsement in provinces other than Ontario). In Ontario, a "Z" endorsement[37] is required to drive any vehicle using air brakes; in provinces other than Ontario, the "A" endorsement is for air brake operation only, and an "S" endorsement is for both operation and adjustment of air brakes. Anyone holding a valid Ontario driver's license (i.e., excluding a motorcycle license) with a "Z" endorsement can legally drive any air-brake-equipped truck-trailer combination with a registered- or actual-gross-vehicle-weight (i.e., including towing- and towed-vehicle) up to 11tonnes, that includes one trailer weighing no more than 4.6tonnes if the license falls under the following three classes: Class E (school bus—maximum 24-passenger capacity or ambulance), F (regular bus—maximum 24-passenger capacity or ambulance) or G (car, van, or small-truck).
A Class B (any school bus), C (any urban-transit-vehicle or highway-coach), or D (heavy trucks other than tractor-trailers) license enables its holder to drive any truck-trailer combination with a registered- or actual-gross-vehicle-weight (i.e., including towing- and towed-vehicle) greater than 11tonnes, that includes one trailer weighing no more than 4.6tonnes.[38] Anyone holding an Ontario Class A license (or its equivalent) can drive any truck-trailer combination with a registered- or actual-gross-vehicle-weight (i.e., including towing- and towed-vehicles) greater than 11 tonnes, that includes one or more trailers weighing more than 4.6 tonnes.
United States
Drivers of semi-trailer trucks generally require a Class A commercial driver's license (CDL) to operate any combination vehicles with a gross combination weight rating (or GCWR) in excess of 26,000lb (11,800kg) if the gross vehicle weight rating (GVWR) of the towed vehicle(s) is in excess of 10,000lb (4,500kg). Some states (such as North Dakota) provide exemptions for farmers, allowing non-commercial license holders to operate semis within a certain air-mile radius of their reporting location. State exemptions, however, are only applicable in intrastate commerce; stipulations of the Code of Federal Regulations (CFR) may be applied in interstate commerce.  Also a person under the age of 21 cannot operate a commercial vehicle outside the state where the commercial license was issued.  This restriction may also be mirrored by certain states in their intrastate regulations.  A person must be at least 18 in order to be issued a commercial license.
In addition, endorsements are necessary for certain cargo and vehicle arrangements and types;
H – Hazardous Materials (HazMat or HM) – necessary if materials require HM placards.
N – Tankers – the driver is acquainted with the unique handling characteristics of liquids tankers.
X – Signifies Hazardous Materials and Tanker endorsements, combined.
T – Doubles & Triples – the licensee may pull more than one trailer.
P – Buses – Any Vehicle designed to transport 16 or more passengers (including the driver).
S – School Buses – Any school bus designed to transport 11 or more passengers (including the driver).
W – Tow Truck
Taiwan

The Road Traffic Security Rules (道路交通安全規則) require a combination vehicle driver license (Chinese:聯結車駕駛執照) to drive a combination vehicle (Chinese:聯結車). These rules define a combination vehicle as a motor vehicle towing a heavy trailer, i.e., a trailer with a gross weight of more than 750 kilograms (1,653lb).
Europe
A category CE driving licence is required to drive a tractor-trailer in Europe. Category C (Γ in Greece) is required for vehicles over 7,500kg (16,500lb), while category E is for heavy trailers, which in the case of trucks and buses means any trailer over 750kg (1,650lb). Vehicles over 3,500kg (7,700lb)—which is the maximum limit of B license—but under 7,500 kg can be driven with a C1 license. Buses require a D (Δ in Greece) license. A bus that is registered for no more than 16 passengers, excluding the driver, can be driven with a D1 license.
Australia
Truck drivers in Australia require an endorsed license. These endorsements are gained through training and experience. The minimum age to hold an endorsed license is 18years, and/or must have held open (full) driver's license for minimum 12months.
The following are the heavy vehicle license classes in Australia:
LR (Light Rigid) – Class LR covers a rigid vehicle with a GVM (gross vehicle mass) of more than 4.5tonnes but not more than 8 tonnes. Any towed trailer must not weigh more than 9tonnes GVM. Also includes vehicles with a GVM up to 8 tonnes which carry more than 12 adults including the driver and vehicles in Class C.
MR (Medium Rigid) – Class MR covers a rigid vehicle with two axles and a GVM of more than 8 tonnes. Any towed trailer must not weigh more than 9tonnes GVM. Also includes vehicles in Class LR.
HR (Heavy Rigid) – Class HR covers a rigid vehicle with three or more axles and a GVM of more than 15 tonnes. Any towed trailer must not weigh more than 9tonnes GVM. Also includes articulated buses and vehicles in Class MR.
HC (Heavy Combination) – Class HC covers heavy combination vehicles like a prime mover towing a semi-trailer, or rigid vehicles towing a trailer with a GVM of more than 9 tonnes. Also includes vehicles in Class HR.
MC (Multi Combination) – Class MC covers multi-combination vehicles like road trains and B-double vehicles. Also includes vehicles in Class HC.
In order to obtain an HC License the driver must have held an MR or HR license for at least 12 months. To upgrade to an MC License the driver must have held a HR or HC license for at least 12 months. From licenses MR and upward there is also a B Condition which may apply to the license if testing in a synchromesh or automatic transmission vehicle. The B Condition may be removed upon the driver proving the ability to drive a constant mesh transmission using the clutch. Constant mesh transmission refers to crash box transmissions, predominantly Road Ranger eighteen-speed transmissions in Australia.
New Zealand
In New Zealand, drivers of heavy vehicles require specific licenses, termed as classes. A Class 1 license (car license) will allow the driving of any vehicle with Gross Laden Weight (GLW) or Gross Combination Weight (GCW) of 6,000kg (13,000lb) or less. For other types of vehicles the classes are separately licensed as follows:
Class 2 – Medium Rigid Vehicle: Any rigid vehicle with GLW 18,001kg (39,685lb) or less with light trailer of 3,500kg (7,700lb) or less, any combination vehicle with GCW 12,001kg (26,458lb) or less, any rigid vehicle of any weight with no more than two axles, or any Class 1 vehicle.
Class 3 – Medium Combination Vehicle: Any combination vehicle of GCW 25,001kg (55,118lb) or less, or any Class 2 vehicle.
Class 4 – Heavy Rigid Vehicle: Any rigid vehicle of any weight, any combination vehicle which consists of a heavy vehicle and a light trailer, or any vehicle of Class 1 or 2 (but not 3).
Class 5 – Heavy Combination Vehicle: Any combination vehicle of any weight, and any vehicle covered by previous classes.
Class 6 – Motorcycle.
Further information on the New Zealand licensing system for heavy vehicles can be found at the .
Role in trade
Modern day semi-trailer trucks often operate as a part of a domestic or international transport infrastructure to support containerized cargo shipment.
Various types of rail flat bed train cars are modified to hold the cargo trailer or container with wheels or without. This is called Intermodal or piggyback. The system allows the cargo to switch from highway to railway or vice versa with relative ease by using gantry cranes.
The large trailers pulled by a tractor unit come in many styles, lengths, and shapes. Some common types are: vans, reefers, flatbeds, sidelifts and tankers. These trailers may be refrigerated, heated, ventilated, or pressurized, depending on climate and cargo. Some trailers have movable wheel axles that can be adjusted by moving them on a track underneath the trailer body and securing them in place with large pins. The purpose of this is to help adjust weight distribution over the various axles, to comply with local laws.
Media

Television
1960s TV series Cannonball
NBC ran two popular TV series about truck drivers in the 1970s featuring actor Claude Akins in major roles:
Movin' On (1974–1976)
B. J. and the Bear (1978–1981)
The Highwayman (1987-1988), a semi-futuristic action-adventure series starring Sam Jones, featuring hi-tech, multi-function trucks.
Knight Rider, an American television show featured a semi-trailer truck called The Semi, operated by the Foundation for Law & Government (F.L.A.G.) as a mobile support facility for KITT. Also, in two episodes KITT faced off against an armored semi called Goliath.
The Transformers, a 1980s cartoon featuring tractor-trailers as the Autobots' leader Optimus Prime (Convoy in Japanese version), their second-in-command Ultra Magnus, and as the Stunticons' leader Motormaster. Optimus Prime returned in the 2007 film.
Trick My Truck, a CMT show features trucks getting 'tricked out' (heavily customized).
Ice Road Truckers, a History Channel show charts the lives of drivers who haul supplies to remote towns and work sites over frozen lakes that double as roads.
18 Wheels of Justice, featuring Federal Agent Michael Cates (Lucky Vanous) as a crown witness for the mafia who goes undercover, when forced into it, to fight crime.
Eddie Stobart: Trucks & Trailers, a UK television show showing the trucking company Eddie Stobart and its drivers.
Highway Thru Hell, a Canadian reality TV show that follows the operations of Jamie Davis Motor Trucking, a heavy vehicle rescue and recovery towing company based in Hope, British Columbia.
Films
Duel, Steven Spielberg's 1971 film, features a Peterbilt 281 tanker truck from Australia as the villain
White Line Fever, a 1975 Columbia Pictures film, starring Jan-Michael Vincent
Maximum Overdrive, Stephen King's 1986 film, featured big rigs as its primary homicidal villains
Smokey and the Bandit, a 1977 film featuring a number of trucks on the side of the bandit
Convoy, a 1978 film directed by Sam Peckinpah, starring Kris Kristofferson
Black Dog, a 1998 film directed by Kevin Hooks, starring Patrick Swayze
Primemover, a 2008 film directed by David Caesar
Joy Ride, a 2001 film directed by John Dahl, starring Paul Walker and Steve Zahn
Big Rig, a 2008 documentary film directed by Doug Pray
Music
"Convoy", a pop song by C. W. McCall, spurred sales of CB radios with an imaginary trucking story.
The eighteen-wheeled truck was immortalized in numerous country music songs, such as the Red Sovine titles "Giddyup Go", "Teddy Bear" and "Phantom 309", and Dave Dudley's "Six Days on the Road".
The thrash metal band, BigRig, was named after these trucks.
Country song "Eighteen Wheels and a Dozen Roses", made popular in 1987 by singer-songwriter Kathy Mattea.
"Roll On (Eighteen Wheeler)" by Alabama tells the story of a trucker who calls home to his family every night while out on the road.
"Papa Loved Mama" by Garth Brooks is about a trucker and his wife.
"Truck Drivin' Song" by "Weird Al" Yankovic tells the story of a female trucker, sung by a male with a deep voice.
"Cold Shoulder" by Garth Brooks is about a trucker stuck on the side of the highway during a blizzard, fantasizing about being home with his wife.
"Drivin' My Life Away" by Eddie Rabbitt, a former trucker, co-written with Even Stevens and David Malloy, sings of the life on the road.
Video games

18 Wheels of Steel series
American Truck Simulator
Big Rigs: Over the Road Racing (2003)
Euro Truck Simulator
Euro Truck Simulator 2
Hard Truck (1998)
MotorStorm and MotorStorm: Pacific Rift
Rig 'n' Roll (2009)
Rigs of Rods[39]

See also

Air brake (road vehicle)
Articulated lorries
Articulated vehicle
Brake
Bus
Containerization
DAT Solutions (a.k.a. Dial-a-truck)
Dolly (trailer)
Drayage
Dump truck
Gladhand connector
Hybrid vehicle
Jackknifing
List of trucks
Loader crane
Loading dock
Logging truck
Long combination vehicle
Oversize load
Progressive shifting
Refrigerator truck ("reefer")
Road train
Semi-trailer
Terminal tractor
Tank truck
Tractor unit
Trailer (vehicle)
Trailer bus
Train
Truck
Truck driver

, dedicated to trucking information in UK and Europe
, safety and education in and around trucking in the US


The Burntisland Shipbuilding Company was a shipbuilder and repairer in Burntisland, Fife, Scotland that was founded in 1918.[1] In 1969 it was taken over by Robb-Caledon Shipbuilders, which in turn was nationalised in 1977 as part of British Shipbuilders.
In the 1970s the Burntisland yard switched from shipbuilding to prefabricating modules of superstructure for offshore oil platforms, but orders were intermittent and by the 1980s the yard was largely idle. In 1990 new owners returned the yard to production as Burntisland Fabrications or BiFab, resuming the manufacture of superstructure modules for oil platforms. Under a management buyout in 2001 the Burntisland yard returned to being an independent company.[2]
Founding and early years
Brothers Amos and Wilfrid Ayre founded Burntisland Shipbuilding Co. in 1918 as a First World War emergency shipyard.[1] Its yard at Burntisland West Dock had four berths and capacity to build ships up to 450 feet (140m) long[1] and up to 59 feet (18m) beam.[3] However, until the 1950s Burntisland built relatively few vessels more than about 425 feet (130m) long and 57 feet (17.4m) beam.[3]
The yard was connected to the North British Railway by an extensive internal rail network that carried steel to various parts of the yard.[1]
Burntisland's first three vessels were standard "C" type cargo ships[1] of just over 3,100 GRT each for the UK Government's wartime Shipping Controller, laid down in 1918 as hull numbers 101, 102 and 103.[3] They were launched in 1919 after the Armistice: hull 101 in June as War Brosna, 102 in September as War Dodder and 103 in November as War Tolka.[3]
Burntisland's first peacetime order was for a pair of 2,300 GRT cargo steamers for Compagnie Lasry of Oran, Algeria.[3] Hulls 104 and 105 were launched in 1920 as Nelly Lasry and Sidney Lasry.[3] In the 1920s the yard built merchant ships ranging from coasters of about 600 tons to ocean-going cargo ships of up to 4,700 tons GRT.[3] Most common were ocean-going four- or five-hold[1] tramp steamers of 1,500 to 2,500 tons.[3]
The yard also built a number of arch-deck colliers[3] from 900 to 2,300 tons GRT.[3] Burntisland built numerous flatiron colliers with low superstructures, hinged funnel and hinged or telescopic mast(s) to fit under bridges upriver from the Pool of London on the River Thames.[1] Burntisland's first flatiron was hull 119, launched in 1922 as the 932 GRT coastal collier Wandle for the Wandsworth, Wimbledon and Epsom District Gas Company.[3] From 1923 to 1946 Burntisland built a further 11 colliers for the same customer, which from 1932 was called the Wandsworth and District Gas Company.[3]
Surviving the Great Depression
Being built in 1918 the yard was modern, well-equipped and thus well-placed to compete during the Great Depression. In 1929 the company introduced its
"Burntisland Economy" ship design, intended for maximum fuel efficiency.[1] The concept was popular with ship-owners during the depression and Burntisland continued the design with a succession of developments during the 1930s.[1]
Some ships that Burntisland built for shipping companies went on to become Empire ships under the Ministry of War Transport in the Second World War. Hull 164, launched in 1935 as Roxburgh, became Empire Tower in 1942. Hull 207, launched in 1937 as Ginnheim, became Empire Ouse in 1945.[3]
Burntisland continued to build numerous colliers. Hulls 171 and 172, launched in 1932 as Alexander Kennedy and Ferranti, were a pair of 1,315 GRT flatirons for the London Power Company,[3] which operated Battersea Power Station and Deptford Power Station. Burntisland went on to build six further colliers for the LPC between 1933 and 1945.[3]

Hull 173 was launched in 1932 as Wandle, a 1,482 GRT flatirons for the Wandsworth, Wimbledon and Epsom District Gas Company.[3] She replaced the previous Wandle that Burntisland had built for the same owner in 1922 (see above).[3]
Hull 174 was launched in 1933 as London Queen, a 781 GRT coaster for the London and Channel Islands Shipping Company.[3] Her owners became British Channel Islands Shipping Co, for whom Burntisland launched a further seven ships between 1937 and 1948.[3]
Hulls 178 and 179, launched in 1933 and 1934 as Pulborough and Petworth, were for Stephenson, Clarke and Associates.[3] Burntisland went on to build eight ships for Stephenson, Clarke spread over nearly 30 years, the last being hull 398 launched in 1961 as MV Gilsland.[3]
Hull 184, launched in 1934 as MV<i>Charles M, was Burntisland's first diesel ship.[3] She was a 403 GRT coaster with a Humboldt-Deutz engine and was built for T.J. Metcalf of London.[3] Burntisland built a second Humboldt-Deutz-engined motor coaster for Metcalf, hull 196, that was launched in 1936 as MV<i>Daniel M.[3]
Hulls 191 and 192, launched in 1935 as Corbrae and Corburn, were for William Cory & Son.[3] Over the next 21 years Burntisland went on to build a total of 17 colliers for Cory, the last two being hulls 376 and 378 launched in 1956 as MV Corstar and MV Corsea.[3]
Hulls 193–195 were a trio of flatirons launched in successive years as Fulham in 1935, Fulham II in 1936 and Fulham III in 1937.[3] They were built for the Metropolitan Borough of Fulham[3] to supply Fulham Power Station. Burntisland went on to build six further flatirons for Fulham between 1938 and 1948.[3]
Hull 213, launched in 1938 as MV Derrymore, was a 4,799 GRT cargo ship for McCowen and Gross of London.[3] Burntisland went on to build a further five ships for McCowen and Gross between 1938 and 1951.[3]
Second World War

During the Second World War Burntisland continued to concentrate on building merchant ships.[1] However, in 1943 it also built three Loch-classfrigates:[1] HMS<i>Loch Fyne, HMS<i>Loch Killin and HMS<i>Loch Glendhu.[3]
In May 1941 Burntisland launched hull 233 as Merton, the first of several large standard-design 7,195 GRT cargo ships for the Carlton Steam Ship Co of Newcastle upon Tyne.[3] War shipping needs and losses called for an unprecedented rate of shipbuilding.[3] In July, August and October 1941 Burntisland launched three further large ships of the same standard design for Carlton.[3] They included Earlston, which was torpedoed and sunk off the North Cape in July 1942 less than a year after her launch.[3] Burntisland launched a further two large ships per year for Carlton in 1942–44.[3]
Also in 1941, Burntisland started to build colliers for the Gas Light and Coke Company to supply Beckton Gas Works in east London. Hull 235 was launched in April as the 2,816 GRT Adams Beck.[3] Burntisland went on to build five further colliers for the GL&CC in the 1940s.[3]
In 1942 Burntisland launched hull 264 as the 7,043 GRT cargo ship MV Highland Prince for Prince Line.[3] In 1944 hull 280 was launched as the 7,150 GRT MV Scottish Prince.[3] Burntisland went on to build eight further merchant ships for Prince line between 1946 and 1960.[3]
Burntisland built a number of war standard ships for the Ministry of War Transport, including the 7,290 GRT hulls 261 and 266 launched as Empire Rosalind and Empire Glory in 1942 and 1943.[3] Other MoWT orders included two merchant aircraft carriers: hull 268 launched in 1942 as MV<i>Empire MacAlpine and hull 277 launched in 1943 as MV<i>Empire MacKendrick.[3] Hulls 291 to 294 were launched in February and March 1944 as CHANT 66 to CHANT 69: part of the large CHANT fleet of 400 GRT prefabricated coastal tankers.[3]
Wartime demand rose so high that in 1944–45 Burntisland subcontracted orders for five coasters to Hall, Russell & Company of Aberdeen: hulls 270, 273, 274, 276 and 281.[3]
In April 1945 Burntisland launched hull 290, the 7,541 GRT Padana for the British-India Steam Navigation Company.[3] BI ordered two more cargo ships from Burntisland after the war (see below).
Completion of MoWT orders continued after the surrender of Germany with the launches of hull 298 in May 1945 as the 1,337 GRT coaster Empire Pacific and finally hull 289 in July as the 7,134 GRT cargo ship MV Empire Calshot.[3]
Post-war production
Burntisland continued to build colliers after the war. Hulls 295 and 301, launched in 1946 as Chessington and Mitcham, were the last two flatirons for the Wandsworth and District Gas Co. Hull 328 was launched in 1948 as MV Adams Beck for the GL&CC.[3] Under the Gas Act 1948 the Wandsworth and District Gas Co became part of South Eastern Gas Board, whom Burntisland supplied with five further flatirons between 1949 and 1956.[3]
Hulls 307 and 308, launched in 1947 and 1948 as the 1,776 GRT MV Fulham VIII and 1,759 GRT MV Fulham IX,[3] were the last two flatirons for Fulham Borough Council before the Electricity Act 1947 nationalised Britain's electricity supply industry. Burntisland supplied one collier for the new state-owned British Electricity Authority: hull 341, launched in 1951 as the 1,837 GRT Brimsdown,[3] named after Brimsdown Power Station in north London.
Burntisland maintained its reputation for high quality tramps and cargo-liners.[1] By 1945 a majority of orders were for motor vessels.[3] Hulls 316 and 317 were a pair of 3,668 GRT sister ships for British-India S.N. Co launched in 1948 as MV<i>Warora and MV<i>Warla.[3] Each had a Barclay Curle-Doxford three-cylinder diesel engine.[3]
Hulls 319–321 were launched for the newly founded Christensen Canadian African Lines as the 3,623 GRT MV Thorshall in May 1948, 3,632 GRT MV Thorstrand in December 1948 and 3,713 GRT MV Thorsisle in March 1949.[3] Each ship had a Hawthorn Leslie-Doxford four-cylinder diesel engine.[3]
Hull 330 was launched in 1949 as MV Sycamore, a 3,343 GRT cargo ship for Johnston Warren Lines of Liverpool.[3] Further orders from Johnston Warren Lines were hulls 353 and 355 launched in 1954 as the 3,596 GRT MV Beechmore and 3,597 GRT MV Pinemore, and hull 385 launched in 1958 as the 6,659 GRT cargo ship MV Mystic.[3]
Hulls 334 and 335 were a pair of 3,364 GRT cargo liners for Prince line, launched in 1950 as MV<i>Afric Prince and MV<i>Egyptian Prince.[3] Each ship had a 300 BHP Hawthorn Leslie four-cylinder diesel engine, a top speed of 14 knots (26km/h) and accommodation for 12 passengers.[3]
Hull 337 was launched in February 1951 as MV Derrymore, a 5,678 GRT cargo ship that replaced one of the same name that Burntisland built for the same customer in 1938.[3] Before the end of 1951 the new Derrymore passed to O. Gross's Power Steam Ship Co as MV Huntsmore.[3] Burntisland built three further ships for Power S.S. Co between 1954 and 1958.[3]
Hull 349 was launched in September 1952 as MV Master Nicos, an 8,453 GRT cargo ship for Motores Maritimos Compañía Limitada, a Greek-owned company registered in Costa Rica.[3] From February 1952 until her launch the resident engineer supervising Master Nicos' construction was Victoria Drummond MBE, the first British woman to have qualified as a marine engineer.[4]
During and after the Second World War the demand for larger cargo ships increased. Burntisland's slipways and berths were limited in size, but in the 1950s the yard managed to build a number of ships of more than 450 feet (140m) length and 60 feet (18.3m) beam.[3] Hull 347, launched in 1954 as the 6,515 GRT MV<i>Huntsland for Power S.S. Co, had a length and beam of 477 feet (145m) and 64 feet (19.5m).[3] Hull 362, launched in 1956 as the 8,390 GRT (11,850 DWT) MV<i>Capetan Cardemalitis for the Tramp Chartering Corporation of Piraeus, had a length, beam and draught of 479 feet (146m), 63 feet (19.2m) and 28 feet (8.5m).[3]
Hull 367, launched in October 1956 as the 1,873 GRT MV Kingston, was the final flatiron collier for the South Eastern Gas Board. She also turned out to be the last of 28 flatirons that Burntisland had built for various customers over a period of 34 years.[3]
In the 1950s The Scottish and Mercantile Investment Co bought a majority shareholding in the company.[1] However, the Ayre brothers continued to manage the business.[1]
By the mid-1950s orders were sufficient for Burntisland to subcontract two coasters to Hall Russell in Aberdeen. In 1956 Hall Russell launched hull 378 as the 3,373 GRT MV Corsea for Wm. Cory.[3] Hull 379 was launched in Aberdeen as Winga for Glen and Company of Glasgow and completed in 1957.[3] Winga proved to be Burntisland's last steam-powered ship.[3]
Turbine steamers
In the 1950s there were far fewer orders for ships with reciprocating steam engines. However, geared steam turbines are more compact, more powerful and less vibratory than reciprocating engines. Early in the 1950s Burntisland took two orders for steam turbine cargo ships.
The first order was for a pair of ore carriers for the Panamanian Pan Ore Steam Ship Co, Inc.[3] Hull 352 was launched in 1953 as the 5,000 GRT TSS<i>Dispatcher.[3] Her sister ship hull 351 was launched in 1954 as the 4,952 GRT TSS<i>Discoverer.[3] David Rowan and Company of Glasgow, part of Lithgows Limited,[5] built the turbines and reduction gearing for both ships.[3]
The second turbine order was hull 377, launched in 1956 as TSS<i>Sunvictor for Skibs A/S Geirulv (Gjeruldsen & Tambs) of Arendal, Norway.[3] Her turbine was built by Scotts of Greenock on the River Clyde.[3]
Cancellations and redundancies
In the 1950s Burntisland suffered a number of cancelled orders. Hull 365 was cancelled in 1954 and hull 368 in 1955, but worse came with the cancellation of six hulls in 1959–60.[3] The first three cancelled hulls were all for Power S.S. Co. in about 1959.[3] The last cancellation was hull 396 for Prince Line in about 1960.[3] This left hull 395, launched as the 4,800 GRT MV Lancastrian Prince, as Burntisland's last completed order for Prince Line.
By 2 July 1959 Burntisland Shipbuilding had laid off 100 workers and it was rumoured in the House of Commons that the company was to close down.[6] On 30 October 1959 a new Labour MP, Harry Gourlay, whose Kirkcaldy Burghs constituency included Burntisland, made his maiden speech to the House of Commons.[7] In it he reported that in 1957 about 1,700 people had been employed in shipyards in Kirkcaldy and Burntisland but this workforce had now been reduced to about 800.[7]
On 26 July 1962 Harry Gourlay again expressed concern in the Commons that Burntisland Shipbuilding had made a number of its employees redundant.[8] However, the Conservative MP Frederick Erroll, President of the Board of Trade, replied that the redundancies had not increased unemployment in Burntisland.[8]
On 5 November 1962 Gourlay told the Commons that he blamed the Conservative Government's economic policy for the decline of shipbuilding in the United Kingdom.[9] William Whitelaw MP, Parliamentary Secretary to the Minister of Labour, denied this and replied that the Ministry of Labour planned to create a centre in Fife to retrain redundant workers for alternative employment.[9]
On 14 March and 27 May 1963 and Gourlay told the Commons that Burntisland Shipbuilding had cut its workforce from about 1,500 in 1961 to just over 500 in 1963.[10][11] (An alternative source states that in 1961 Burntisland had 1,000 employees.)[1] On 14 March Gourlay pleaded for small shipyards on the east coast of Scotland such as Burntisland to be awarded War Department contracts[10] and on 27 May he claimed in the Commons that the Local Employment Act had not led to the creation of any new jobs in Burntisland.[11] Whitelaw conceded that the number of shipyard workers unemployed in Burntisland had risen from six in May 1961 to 116 in May 1963.[11]
In 1963 Sir Wilfrid Ayre retired after 45 years at the head of the company.[1]
1960s production
Metcalf Motor Coasters renewed its relationship with Burntisland by ordering five new coastal tankers: hull 399 launched in 1961 as MV Ann M, hull 404 launched in 1962 as MV John M, hull 410 launched in 1964 as MV Frank M, hull 411 launched in 1965 as MV Nicholas M and finally hull 417 launched in 1966 as MV Eileen M.[3]
Burntisland succeeded in securing orders from notable customers. Hull 402, launched in 1962 as MV Montreal City and hull 406, launched in 1964 as MV Halifax City were sister ships of just over 6,500 GRT for Bristol City Line.[3] Hull 403, launched in 1962 as MV Beaverpine, was a 4,514 GRT cargo ship for Canadian Pacific Steamships.[3] Hulls 407 and 408, launched in 1964 as MV Newfoundland and MV Nova Scotia, were a pair of 6,660 GRT sister ships for Furness Withy.[3]
Hulls 414 and 415 were also coastal tankers, built as specialist liquid gas carriers.[3] The sister ships were launched for the Nile Steam Ship Co as MV Teviot in 1965 and MV Traquair in 1966 respectively.[3] Burntisland also built a larger tanker, hull 416, launched in 1965 as the 3,971 GRT MV Olau Mark for Olau Line of Denmark.
MV Ohrmazd and receivership
Hull 418 was launched in April 1967 as the 11,046 GRT MV<i>Ohrmazd, a fast passenger and cargo liner for the East & West Steamship Company of Karachi, Pakistan.[12] However, protracted negotiations with Ohrmazd's owners over the ship's specification delayed her completion until November 1968.[12] This activated a penalty clause in the building contract from which Burntisland Shipbuilding proved unable to recover,[12] and the company went into receivership in 1968.[1]
On 20 December 1968 the Burntisland yard was facing closure and a Conservative MP, James Prior, told the Commons that he hoped it could be averted,[13] but on 22 January 1969 the announcement was made that the yard would close.[14] The next day, 23 January, the Commons debated the Labour Government's Shipbuilding Industry Bill. The Labour MP Gerald Fowler, Joint Parliamentary Secretary to the Ministry of Technology, told the House:
"We in the Ministry of Technology have spared no effort to find, if we can, a commercial solution to this problem to keep this yards in shipbuilding, and the hon. Member for Kirkcaldy Burghs (Mr. Gourlay) has made as strenuous an effort to save this yard, as could be expected of any constituency Member, and all credit is due to him for that, and I hope that his efforts and ours will be rewarded with success."[14]
Under the Shipbuilding Act 1967 the Labour Government offered credit to help the shipbuilding industry. Therefore, during 23 January debate Edward Garrett, Labour MP for Wallsend asked the Minister of Technology, Tony Benn MP, about Burntisland Shipbuilding, "Is it true that since the credit facilities became available little attempt has been made by management, and, I fear, by the Minister, to ascertain whether the medium and small yards are being helped to become more economic?"[14]
A day later, 24 January, the Scottish National Party MP Winnie Ewing asked in the Commons if the Ministry of Technology would form a government holding company to buy the Burntisland yard and keep it and all its employees at work.[15] Gerald Fowler said that it would not, and "the best hope of a long-term solution would be if a shipbuilding undertaking which can find orders capable of being carried out profitably at this yard were to take it over".[15]
On 29 January in the Commons Willie Hamilton, Labour MP for West Fife, called for a public enquiry into the causes of the Burntisland yard's closure.[16] In his reply, Gerald Fowler said:
"I hope that we can reach a commercial and viable solution which will enable the yard to stay in production. However, I must point out that the assistance voted by this House in the Shipbuilding Industry Act was meant to be used not to save uneconomic yards but to assist reorganisation with a view to promoting competitiveness in the industry. If the Burntisland yard fits that pattern, I shall be pleased, but I do not think that an inquiry would help us as of now."[16]
Final ships
Burntisland launched four more ships after launching Ohrmazd. Hull 419, launched in 1967 as MV Peter Schröder and hull 420, launched in 1968 as MV Paul Schröder, were a pair of cargo ships each of just over 5,000 GRT for Reederei Richard Schröder of Hamburg, Germany. Hull 421, launched in 1968 as MV Christiane Bolten, was a similar cargo ship for another Hamburg customer, the long-established August Bolten William Miller's Nachfolger. Hull 422 was the yard's final vessel, another cargo ship similar to the Peter Schröder and Paul Schröder. She was launched in April 1969 as MV<i>Helen Miller[3] for the St. Vincent Shipping Co. of Liverpool and completed ahead of schedule that July.[12] The yard then made about 800 of its remaining workers redundant.[17]
On 30 April 1970, during another Shipbuilding Bill debate in the Commons, the Liberal MP Jo Grimond asked "Is there any news about the site at Burntisland? ... I understand that it is out of shipbuilding. Is it out of the industry altogether? Is it being used on prefabrication or for any other purpose?"[18] Harold Lever MP, Paymaster General, replied that the Burntisland yard "is now satisfactorily in the East Scotland Group and quite active." Grimond immediately asked "Will it build again?", to which Lever replied "I think it is building now. It is functioning well in another reasonably successful group."[18]
Burntisland's new owner was Robb-Caledon Shipbuilders of Leith and Dundee. On 31 January 1972 Gourlay told the Commons "Now there are only 80 persons employed there [i.e. at Burntisland yard], and even their jobs are in jeopardy unless something is done very soon."[17] His Labour colleague Dick Douglas MP added:
"My hon. Friend indicates a specific problem. It may be that the good offices of the Department can be used to ensure that some of the work that Robb Caledon takes on board is dispersed not only to the Burntisland yard but to the Dundee yard, in view of the present high level of unemployment. The male rate is running at 12.3 per cent., and the local figure is 9.8 per cent. of the insured population of Dundee and Broughty Ferry."[17]
Burntisland still built no more ships, and on 11 February 1972 Robb-Caledon made another 10 workers at Burntisland redundant[19] In the Commons on 6 March 1972 Gourlay again pleaded for Government money to help keep the yard open.[20] The Conservative MP Nicholas Ridley replied that the Department for Trade and Industry had no proposals to help Robb-Caledon.[20] Robb-Caledon eventually removed Burntisland's equipment to its other yards.[1][12]
Offshore oil and gas fabrications
Robb-Caledon eventually succeeded in attracting orders to build structures for Scotland's North Sea oil and natural gas industry. By December 1972 Burntisland was building a structure for Shell's Auk oilfield.[21] This was followed in 1973 by an order for modules for North Sea oil platforms.[22] By November 1974 Robb-Caledon had formed a Burntisland Engineering Fabricators (BEF) subsidiary and the yard was building modules for the Norwegian sector of the North Sea, but Gourlay complained in the Commons that the yard had lost a potential order for an oil rig to an overseas competitor for reasons of cost and "the geographical conditions on the site".[23]
In April 1975 John Smith MP, Under-Secretary of State for the Department of Energy told the Commons that BEF was one of the UK's two largest constructors for the offshore oil and gas industry.[24] It had not secured orders for offshore platforms but had become the UK's leading builder of modules to fit on them.[24] In December 1975 Gregor Mackenzie MP, a minister at the Department of Industry told the Commons that his department had lent BEF £450,000 under the Industry Act 1972, had given its parent company Robb-Caledon a £400,000 loan and almost £1.1 million in grants and the company was also eligible for grants under the Local Employment Act.[25]
Nationalisation and closure

Under the Aircraft and Shipbuilding Industries Act 1977 the Labour Government nationalised the UK's shipbuilding industry. Robb-Caledon became a wholly owned subsidiary of British Shipbuilders, which thereby held a 52% share in BEF.[26]
On 7 January 1979 Burntisland was nearing completion of its current order and Gourlay asked in the Commons whether the Secretary of State for Industry "will hold discussions to ensure the continuing operation of the yard at Burntisland when the present contract is completed".[27] Les Huckfield MP replied on behalf of the Secretary of State "Although there are no further orders in prospect for the yard, British Shipbuiders is using its best endeavours to sell the yard as a going concern, thereby preserving employment".[27]
On 24 October 1979 Gourlay told the Commons of the closure of the Burntisland yard and asked what George Younger MP, Secretary of State for Scotland would do to help the unemployed to find to re-employment.[28]
Revival
In 1990 under new owners Burntisland West Dock resumed the production of major offshore oil and gas fabrications. In 2001 a management buyout took over the yard as Burntisland Fabrications or BiFab. The company now also owns a yard at Methil[2] in Fife and a facility at Arnish on Lewis in the Outer Hebrides.[29]
Football club

In 1919 a recreation fund was established, funded by a weekly subscription from the workers' wages. The fund created a cricket team, bowls team and two football teams. In 1925 the football teams were constituted as Burntisland Shipyard Amateur F.C., and since 1929 the club has competed in the qualifying stages of the Scottish Cup. The club is a member of the Kingdom Caledonian Football League.

Further reading

Photograph of  on Picasa web albums
Photograph of  on ShipsAndHarbours.com
Photograph of  on Shipspotting.com

Who founded the Burntisland Shipbuilding Company?


Main Page

The Family That Walks On All Fours is a BBC Two documentary  that explored the science and the story of five individuals in the Ulas family, a Kurdish family in Southeastern Turkey that walk with a previously unreported quadruped gait.[1][2][3][4]
The documentary about the Kurdish family in Turkey was created by Passionate Productions and was broadcast on 17 March 2006. The narrator is Jemima Harrison. A revised version of the documentary that shifts the focus away from the story of the discovery of the family and includes the views of additional scientists was shown on NOVA on 14 November 2006.[5]
Background
Debate exists as to the nature and cause of the family's walking, including controversial speculation in the form of the Uner Tan syndrome that it may be a genetic throwback to pre-bipedal hominid locomotion. However, Nicholas Humphrey, who accompanied the documentary makers, concluded that it was due to a rare set of genetic and developmental circumstances coming together. First, their mother recalls that initially all of her 19 children started off walking with a bear-crawl (i.e. on their feet rather than their knees). Second, due to an inherited recessive genetic mutation, they have a non-progressive congenital cerebellar ataxia that impairs the balance children normally use to learn to walk bipedally. Not being able to manage the balance needed for bipedal walking, they perfected in its place their initial bear-crawl into an adult quadruped gait. The family's walking likely has nothing to do with genes involved in the human evolution of upright walk.
Synopsis
In June 2005, Nicholas Humphrey receives a call from Dr. John Skoyles who has seen an unpublished paper by Turkish Professor Uner Tan that focuses upon hand dominance in the family.
In the film, Two British scientists and Tan visit the family and their father, Resit. There are 19 children in the family, 12 of them typical, and seven were handicapped, one of whom died.  The commentary first introduces Gülin and notes that he "staggers as if he's drunk" but walks on two feet. Then each of the affected hand-walking individuals is introduced: the four sisters Safiye, Hacer, Senem and Emine, and their brother, Hüseyin.
Contrasting with these scenes of sadness, we then see the family enjoying themselves at a sandy beach only an hour’s drive away. In spite of its nearness, they have never been to the sea before. They are shown paddling and touching the sea waves. Hatice, their mother, upon seeing the sea for the first time in her life, says that she did not know that Allah had made such beauty.
The narrator explains that it has been explained to the family that the film will put the world’s spotlight on them. Resit says does not want them compared to monkeys. He does not believe in evolution but also he philosophically observes words cannot harm them and film might bring help and a little understanding. Professor Nicholas Humphrey expresses his concern that this phenomenon may never be seen again.
In January 2006, the film makers return to the family. Before they left, parallel bars had been bought on Dr. Ali’s advice and put outside so the family could exercise upright walking and they have done this nearly every day. The family is seen smiling as they have made progress in learning to walk - and the film closes with Hüseyin walking up a path on two legs.
Production crew
Writer, director, narrator and editor: Jemima Harrison
Photographer and producer: Jon Lane
Computer model: Premog
Titles: Alex Pritchard
Additional photography: Darren Hercher
Production Assistant: Chloe Hayward
Additional Research: David Boardman
Archive researcher: Elizabeth Ashe
Colourist: Malcom Merdith
Dubbing mixer: Matt Skilton
Online Editor: Jim Dummett
Executive Producer for BBC: Richard Klein
Consultants, Turkey: Defne Aruoba, Cetin Mursalioğlu
Consultants, UK: Nick Humphrey, Roger Keynes, John Skoyles
See also
Knuckle-walking

Humphrey, N., Keynes, R. & Skoyles, J. R. (2006).
 on IMDb

What was Jemima Harrison's first film production?