A bogie is a chassis or framework that carries a wheelset, attached to a vehicle—a modular subassembly of wheels and axles. Bogies take various forms in various modes of transport. A bogie may remain normally attached or be quickly detachable. It may include a suspension component within it, or be solid and in turn be suspended ; it may be mounted on a swivel, as traditionally on a railway carriage or locomotive, additionally jointed and sprung, or held in place by other means.
A disc brake is a type of brake that uses the calipers to squeeze pairs of pads against a disc or a rotor to create friction. There are two basic types of brake pad friction mechanisms: abrasive friction and adherent friction. This action slows the rotation of a shaft, such as a vehicle axle, either to reduce its rotational speed or to hold it stationary. The energy of motion is converted into heat, which must be dispersed.
A railroad switch (AE), turnout, or [set of] points (CE) is a mechanical installation enabling railway trains to be guided from one track to another, such as at a railway junction or where a spur or siding branches off.
On 3 June 1998, an ICE 1 train on the Hannover-Hamburg railway near Eschede in Lower Saxony, Germany derailed and crashed into an overpass that crossed the railroad, which then collapsed onto the train. 101 people were killed and at least 88 were injured, making it the second-deadliest railway disaster in German history after the 1939 Genthin rail disaster, and the world's worst ever high-speed rail disaster.
Rail transport terms are a form of technical terminology applied to railways. Although many terms are uniform across different nations and companies, they are by no means universal, with differences often originating from parallel development of rail transport systems in different parts of the world, and in the national origins of the engineers and managers who built the inaugural rail infrastructure. An example is the term railroad, used in North America, and railway, generally used in English-speaking countries outside North America and by the International Union of Railways. In English-speaking countries outside the United Kingdom, a mixture of US and UK terms may exist.
A railgrinder is a maintenance of way vehicle or train used to restore the profile and remove irregularities from worn tracks to extend its life and to improve the ride of trains using the track. Rail grinders were developed to increase the lifespan of the tracks being serviced for rail corrugation. Rail grinding is a process that is done to stop the deformation due to use and friction on railroad tracks by removing deformations and corrosion. Railway tracks that experience continual use are more likely to experience corrugation and overall wear. Rail grinders are used to grind the tracks when rail corrugation is present, or before corrugation begins to form on the tracks. Major freight train tracks use rail grinders for track maintenance based on the interval of tonnage, rather than time. Transit systems and subways in major cities continue to use scheduled rail grinding processes to combat the corrugation common to heavily used tracks. Rail-grinding equipment may be mounted on a single self-propelled vehicle or on a dedicated rail-grinding train which, when used on an extensive network, may include crew quarters. The grinding wheels, of which there may be more than 100, are set at controlled angles to restore the track to its correct profile.
Boylston station is a light rail station on the MBTA Green Line in downtown Boston, Massachusetts, located on the southeast corner of Boston Common at the intersection of Boylston Street and Tremont Street. A southbound street-level stop for the SL5 route of the bus rapid transit Silver Line is outside fare control. The station has two island platforms; each has one disused track, making them effectively side platforms. Boylston is not accessible for Green Line trains.
In rail transport, a derailment is a type of train wreck that occurs when a rail vehicle such as a train comes off its rails. Although many derailments are minor, all result in temporary disruption of the proper operation of the railway system and they are a potentially serious hazard.
A lift hill, or chain hill, is an upward-sloping section of track on a roller coaster on which the roller coaster train is mechanically lifted to an elevated point or peak in the track. Upon reaching the peak, the train is then propelled from the peak by gravity and is usually allowed to coast throughout the rest of the roller coaster ride's circuit on its own momentum, including most or all of the remaining uphill sections. The initial upward-sloping section of a roller coaster track is usually a lift hill, as the train typically begins a ride with little speed, though some coasters have raised stations that permit an initial drop without a lift hill. Although uncommon, some tracks also contain multiple lift hills.
An adhesion railway relies on adhesion traction to move the train, and is the most widespread and common type of railway in the world. Adhesion traction is the friction between the drive wheels and the steel rail. Since the vast majority of railways are adhesion railways, the term adhesion railway is used only when it is necessary to distinguish adhesion railways from railways moved by other means, such as by a stationary engine pulling on a cable attached to the cars or by a pinion meshing with a rack.
A defect detector is a device used on railroads to detect axle and signal problems in passing trains. The detectors are normally integrated into the tracks and often include sensors to detect several different kinds of problems that could occur. Defect detectors were one of the inventions which enabled American railroads to eliminate the caboose at the rear of the train, as well as various station agents placed along active routes to detect unsafe conditions. The use of defect detectors has since spread overseas to other railroad systems.
Train noise is vehicle noise made by trains. Noises may be heard inside the train and outside.
Tramway track is used on tramways or light rail operations. As with standard rail tracks, tram tracks have two parallel steel rails, the distance between the heads of the rails being the track gauge. When there is no need for pedestrians or road vehicles to traverse the track, conventional flat-bottom rail is used. However, when such traffic exists, such as in urban streets, grooved rails are used.
Slippery rail, or low railhead adhesion, is a condition of railways (railroads) where contamination of the railhead reduces the traction between the wheel and the rail. This can lead to wheelslip when the train is taking power, and wheelslide when the train is braking. One common cause of contamination is fallen leaves that adhere to the railhead of railway tracks. The condition results in significant reduction in friction between train wheels and rails, and in extreme cases can render the track temporarily unusable. In Britain, the situation is colloquially referred to as "leaves on the line".
A wheelset is a pair of railroad vehicle wheels mounted rigidly on an axle allowing both wheels to rotate together. Wheelsets are often mounted in a bogie – a pivoted frame assembly holding at least two wheelsets – at each end of the vehicle. Most modern freight cars and passenger cars have bogies each with two wheelsets, but three wheelsets are used in bogies of freight cars that carry heavy loads, and three-wheelset bogies are under some passenger cars. Four-wheeled goods wagons that were once near-universal in Europe and Great Britain and their colonies have only two wheelsets; in recent decades such vehicles have become less common as trainloads have become heavier.
Wheel slide protection and wheel slip protection are railway terms used to describe automatic systems used to detect and prevent wheel-slide during braking or wheel-slip during acceleration. This is analogous to ABS and traction control systems used on motor vehicles. It is particularly important in slippery rail conditions.
A flat spot, or wheel flat, also called spalling or shelling, is a fault in railroad wheel shape. A flat spot occurs when a rail vehicle's wheelset stops rotating while the train is still in motion, causing part of the wheel to ablate against the hard steel of the rails. Flat spots are usually caused by use of the emergency brake, or slippery (low-adhesion) conditions that cause wheels to lock up while the train is still moving. Flat spots are more common in the autumn and winter when the rails are slippery.
A train inspection system is one of various systems of inspection which are essential to maintain the safe running of rail transport.
A train wheel or rail wheel is a type of wheel specially designed for use on railway tracks. The wheel acts as a rolling component, typically press fitted onto an axle and mounted directly on a railway carriage or locomotive, or indirectly on a bogie, also called a truck. The powered wheels under the locomotive are called driving wheels. Wheels are initially cast or forged and then heat-treated to have a specific hardness. New wheels are machined using a lathe to a standardized shape, called a profile, before being installed onto an axle. All wheel profiles are regularly checked to ensure proper interaction between the wheel and the rail. Incorrectly profiled wheels and worn wheels can increase rolling resistance, reduce energy efficiency and may even cause a derailment. The International Union of Railways has defined a standard wheel diameter of 920 mm (36 in), although smaller sizes are used in some rapid transit railway systems and on ro-ro carriages.
The cant of a railway track or camber of a road is the rate of change in elevation (height) between the two rails or edges of the road. This is normally greater where the railway or road is curved; raising the outer rail or the outer edge of the road creates a banked turn, thus allowing vehicles to travel round the curve at greater speeds than would be possible if the surface were level.
