Brake (railway)
Encyclopedia
Brake
s are used on the cars
of railway
train
s to enable deceleration, control acceleration (downhill) or to keep them standing when parked. While the basic principle is familiar from road vehicle usage, operational features are more complex because of the need to control multiple linked carriages and to be effective on vehicles left without a prime mover
. Clasp brakes are one type of brakes historically used on trains.
, travelling for the purpose on those vehicles operated the brakes. Some railways fitted a special deep-noted brake whistle to locomotives to indicate to the porters the necessity to apply the brakes. All the brakes at this stage of development were applied by operation of a screw and linkage to brake blocks applied to wheel treads, and these brakes could be used when vehicles were parked. In the earliest times, the porters travelled in crude shelters outside the vehicles, but "assistant guards" who travelled inside passenger vehicles, and who had access to a brake wheel at their posts supplanted them.
The braking effort achievable was limited, and an early development was the application of a steam brake to locomotives, where boiler pressure could be applied to brake blocks on the locomotive wheels. It was also unreliable, as the application of brakes by guards depended upon them hearing and responding quickly to a whistle for brakes.
As train speeds increased, it became essential to provide some more powerful braking system capable of instant application and release by the train driver, described as a continuous brake because it would be effective continuously along the length of the train.
In the UK, the Abbots Ripton rail accident in January 1876 was aggravated by the long stopping distances of express trains without continuous brakes, which -it became clear- in adverse conditions could considerably exceed those assumed when positioning signals. This had become apparent from the trials on railway brakes carried out at Newark
in the previous year, to assist a Royal Commission
then considering railway accidents . In the words of a contemporary railway official, these
More precise results from the Newark trials are not to hand; trials conducted after Abbots Ripton reported the following (for an express train roughly matching one of those involved, like it on a 1 in 200 fall, but unlike it braking under favorable conditions)
However there was no clear technical solution to the problem, because of the necessity of achieving a reasonably uniform rate of braking effort throughout a train, and because of the necessity to add and remove vehicles from the train at frequent points on the journey. (At these dates, unit train
s were a rarity).
The chief types of solution were:
Note: there are a number of variants and developments of all these systems.
The Newark trials showed the braking performance of the Westinghouse air-brakes to be distinctly superior
but for other reasons it was the vacuum system that was generally adopted on UK railways.
—a heavy vehicle provided at the rear of the train and occupied by a guard.
Goods and mineral vehicles were provided with hand brakes by which the brakes could be applied by a hand lever operated by staff on the ground. These hand brakes were used where necessary when vehicles were parked but also when these trains needed to descend a steep gradient; the train then stopped before descending and the guard walked forward to pin down the handles of sufficient brakes to give adequate braking effort. Early goods vehicles had brake handles on one side only and random alignment of the vehicles gave the guard sufficient braking but, from about 1930, so-called "either-side" brake handles were provided. These trains, not fitted with continuous brakes were described as "unfitted" trains and they survived in British practice until about 1985. However, from about 1930, semi-fitted trains were introduced, in which some goods vehicles were fitted with continuous brakes and a proportion of such vehicles marshalled next to the locomotive gave sufficient brake power to run at somewhat higher speeds than unfitted trains.
In the early days of diesel locomotive
s, a purpose-built brake tender was attached to the locomotive to increase braking effort when hauling unfitted trains. The brake tender was low, so that the driver could still see the line and signals ahead if the brake tender was propelled (pushed) ahead of the locomotive, which was often the case.
By 1878 there were over 105 patents in various countries for braking systems, most of which were obviously stillborn.
which used a chain, running the length of the train, to operate brakes on all vehicles simultaneously.
The chain brake was soon superseded by air operated
or vacuum operated
brakes. These brakes used hoses connecting all the wagons of a train, so the driver could apply or release the brakes with a single valve in the locomotive.
These continuous brakes can be simple or automatic, the essential difference being what happens should the train break in two. With simple brakes, pressure is needed to apply the brakes, and all braking power is lost if the continuous hose is broken for any reason. Simple non-automatic brakes are thus useless when things really go wrong, as is shown with the Armagh rail disaster
.
Automatic brakes on the other hand use the air or vacuum pressure to hold the brakes off against a reservoir carried on each vehicle, which applies the brakes if pressure/vacuum is lost in the train pipe. Automatic brakes are thus largely "fail safe", though faulty closure of hose taps can lead to accidents such as the Gare de Lyon accident
.
The standard Westinghouse Air Brake
has the additional enhancement of a triple valve, and local reservoirs on each wagon that enable the brakes to be applied fully with only a slight reduction in air pressure, reducing the time that it takes to release the brakes as not all pressure is voided to the atmosphere.
Non-automatic brakes still have a role on engines and first few wagons, as they can be used to control the whole train without having to apply the automatic brakes.
s rather than the air brakes
used in America and much of the rest of the world. The main advantage of vacuum was that the vacuum can be created by a steam ejector
with no moving parts (and which could be powered by the steam of a steam locomotive
), whereas an air brake system requires a noisy and complicated compressor
.
However, air brakes can be made much more effective than vacuum brakes for a given size of brake cylinder. An air brake compressor is usually capable of generating a pressure of 90 psi (620.5 kPa) vs only 15 psi (103.4 kPa) for vacuum. With a vacuum system, the maximum pressure differential is atmospheric pressure (14.7 psi or 101.4 kPa at sea level, less at altitude). Therefore, an air brake system can use a much smaller brake cylinder than a vacuum system to generate the same braking force. This advantage of air brakes increases at high altitude, e.g. Peru and Switzerland where today vacuum brakes are used by secondary railways. The much higher effectiveness of air brakes and the demise of the steam locomotive have seen the air brake become ubiquitous; however, vacuum braking is still in use in India, in Argentina and in South Africa, but this will be declining in near future.
and coal and ballast wagons
. On passenger coaches, the main reservoir pipe is also used to supply air to operate doors and air suspension.
The system adopted on the Southern Region of British Railways in 1950 is more fully described at Electro-pneumatic brake system on British railway trains
With ECP, a power and control line is installed from wagon to wagon from the front of the train to the rear. Electrical control signals are propagated effectively instantaneously, as opposed to changes in air pressure which propagate at a rather slow speed limited in practice by the resistance to air flow of the pipework, so that the brakes on all wagons can be applied simultaneously rather than from front to rear. This prevents wagons at the rear "shoving" wagons at the front, and results in reduced stopping distance and less equipment wear.
There are two brands of ECP brakes under development, one by New York Air Brake
and the other by Wabtec
. A single standard is desirable, and it is intended that the two types be interchangeable.
. An exception would be made for locomotives which are often turned on turntables or triangles.
On the new Fortescue
railway opened in 2008, wagons are operated in sets, although their direction changes at the balloon loop
at the port. The ECP
connections are on one side only and are unidirectional.
(WABCO), later Wabtec
Faiveley Transport Knorr-Bremse
Rail Vehicle Systems Westinghouse Brake and Signal Company Ltd
(now a division of Knorr-Bremse) New York Air Brake
(now a division of Knorr-Bremse) MZT HEPOS Mitsubishi Electric
Nabtesco Dellner Aflink Hanning & Kahl GmbH LRT trains, Hydraulic Brakes and control components YUJIN Machinery Ltd
Brake
A brake is a mechanical device which inhibits motion. Its opposite component is a clutch. The rest of this article is dedicated to various types of vehicular brakes....
s are used on the cars
Railroad car
A railroad car or railway vehicle , also known as a bogie in Indian English, is a vehicle on a rail transport system that is used for the carrying of cargo or passengers. Cars can be coupled together into a train and hauled by one or more locomotives...
of railway
Rail transport
Rail transport is a means of conveyance of passengers and goods by way of wheeled vehicles running on rail tracks. In contrast to road transport, where vehicles merely run on a prepared surface, rail vehicles are also directionally guided by the tracks they run on...
train
Train
A train is a connected series of vehicles for rail transport that move along a track to transport cargo or passengers from one place to another place. The track usually consists of two rails, but might also be a monorail or maglev guideway.Propulsion for the train is provided by a separate...
s to enable deceleration, control acceleration (downhill) or to keep them standing when parked. While the basic principle is familiar from road vehicle usage, operational features are more complex because of the need to control multiple linked carriages and to be effective on vehicles left without a prime mover
Prime mover (locomotive)
In engineering, a prime mover is an engine that converts fuel to useful work. In locomotives, the prime mover is thus the source of power for its propulsion. The term is generally used when discussing any locomotive powered by an internal combustion engine...
. Clasp brakes are one type of brakes historically used on trains.
Early days
In the earliest days of railways, braking technology was primitive. The first trains had brakes operative on the locomotive tender and on vehicles in the train, where "porters" or, in the United States brakemenBrakeman
A brakeman is a rail transport worker whose original job it was to assist the braking of a train by applying brakes on individual wagons. The advent of through brakes on trains made this role redundant, although the name lives on in the United States where brakemen carry out a variety of functions...
, travelling for the purpose on those vehicles operated the brakes. Some railways fitted a special deep-noted brake whistle to locomotives to indicate to the porters the necessity to apply the brakes. All the brakes at this stage of development were applied by operation of a screw and linkage to brake blocks applied to wheel treads, and these brakes could be used when vehicles were parked. In the earliest times, the porters travelled in crude shelters outside the vehicles, but "assistant guards" who travelled inside passenger vehicles, and who had access to a brake wheel at their posts supplanted them.
The braking effort achievable was limited, and an early development was the application of a steam brake to locomotives, where boiler pressure could be applied to brake blocks on the locomotive wheels. It was also unreliable, as the application of brakes by guards depended upon them hearing and responding quickly to a whistle for brakes.
As train speeds increased, it became essential to provide some more powerful braking system capable of instant application and release by the train driver, described as a continuous brake because it would be effective continuously along the length of the train.
In the UK, the Abbots Ripton rail accident in January 1876 was aggravated by the long stopping distances of express trains without continuous brakes, which -it became clear- in adverse conditions could considerably exceed those assumed when positioning signals. This had become apparent from the trials on railway brakes carried out at Newark
Newark-on-Trent
Newark-on-Trent is a market town in Nottinghamshire in the East Midlands region of England. It stands on the River Trent, the A1 , and the East Coast Main Line railway. The origins of the town are possibly Roman as it lies on an important Roman road, the Fosse Way...
in the previous year, to assist a Royal Commission
Royal Commission
In Commonwealth realms and other monarchies a Royal Commission is a major ad-hoc formal public inquiry into a defined issue. They have been held in various countries such as the United Kingdom, Australia, Canada, New Zealand, and Saudi Arabia...
then considering railway accidents . In the words of a contemporary railway official, these
showed that under normal conditions it required a distance of 800 to 1200 yards to bring a train to rest when travelling at 45 to 48 mph, this being much below the ordinary travelling speed of the fastest express trains. Railway officials were not prepared for this result and the necessity for a great deal more brake power was at once admitted
More precise results from the Newark trials are not to hand; trials conducted after Abbots Ripton reported the following (for an express train roughly matching one of those involved, like it on a 1 in 200 fall, but unlike it braking under favorable conditions)
| Braking system | Train speed (mph) | Stopping distance (yards) | Stopping time (s) |
|---|---|---|---|
| Continuous (vacuum) | 45 | 410 | 26 |
| Continuous (vacuum) | 45 | 451 | 30 |
| 3 brake vans | 40.9 | 800 | 59 |
| 2 brake vans | 40.9 | 631 | 44 |
| 2 brake vans | 45 | 795 | 55 |
| 1 brake van | 45 | 1125 | 70 |
However there was no clear technical solution to the problem, because of the necessity of achieving a reasonably uniform rate of braking effort throughout a train, and because of the necessity to add and remove vehicles from the train at frequent points on the journey. (At these dates, unit train
Unit train
A unit train, also called a block train, is a railway train in which all the cars making it up are shipped from the same origin to the same destination, without being split up or stored en route...
s were a rarity).
The chief types of solution were:
- The chain brake, such as the Heberlein brakeHeberlein brakeHeberlein brake is a continuous railway brake used in Germany that is applied by means of a mechanical cable. Train braking is therefore initiated centrally from the locomotive using a winder. This causes the brake clips to be applied on individual wagons, assisted by a servo system which makes use...
, in which a chain was connected continuously along the train. When pulled tight it activated a friction clutch that used the rotation of the wheels to tighten a brake system at that point; this system has severe limitations in length of train capable of being handled, and of achieving good adjustment. - Hydraulic brakes. As with car brakes; actuating pressure to apply brakes was transmitted hydraulically. These found some favour in the UK (e.g. with the Midland and Great Eastern Railways), but even in the UK problems were found with the water used as brake fluid freezing
- The WestinghouseGeorge WestinghouseGeorge Westinghouse, Jr was an American entrepreneur and engineer who invented the railway air brake and was a pioneer of the electrical industry. Westinghouse was one of Thomas Edison's main rivals in the early implementation of the American electricity system...
air brake system. In this system, air reservoirs are provided on every vehicle and the locomotive charges the train pipe with a positive air pressure, which releases the vehicle brakes and charges the air reservoirs on the vehicles. If the driver applies the brakes, his brake valve releases air from the train pipe, and triple valves at each vehicle detect the pressure loss and admit air from the air reservoirs to brake cylinders, applying the brakes. The Westinghouse system uses smaller air reservoirs and brake cylinders than the corresponding vacuum equipment, because a moderately high air pressure can be used. However, an air compressor is required to generate the compressed air and in the earlier days of railways, this required a large reciprocating steam air compressor, and this was regarded by many engineers as highly undesirable. - The simple vacuum system. An ejector on the locomotive created a vacuum in a continuous pipe along the train, allowing the external air pressure to operate brake cylinders on every vehicle. This system was very cheap and effective, but it had the major weakness that it became inoperative if the train became divided or if the train pipe was ruptured.
- The automatic vacuum brake. This system was similar to the simple vacuum system, except that the creation of vacuum in the train pipe exhausted vacuum reservoirs on every vehicle and released the brakes. If the driver applied the brake, his driver's brake valve admitted atmospheric air to the train pipe, and this atmospheric pressure applied the brakes against the vacuum in the vacuum reservoirs. Being an automatic brake, this system applies braking effort if the train becomes divided or if the train pipe is ruptured. Its disadvantage is that the large vacuum reservoirs were required on every vehicle, and their bulk and the rather complex mechanisms were seen as objectionable.
Note: there are a number of variants and developments of all these systems.
The Newark trials showed the braking performance of the Westinghouse air-brakes to be distinctly superior
| Braking system | Train weight with engine | Train speed (mph) | Stopping distance (yards) | Time to stop (s) | Decceleration (g) | Rails |
|---|---|---|---|---|---|---|
| Westinghouse automatic | 203t 4cwt | 52 | 304 | 19 | 0.099 | dry |
| Clark hydraulic | 198t 3cwt | 52 | 404 | 22.75 | 0.075 | dry |
| Smith vacuum | 262t 7cwt | 49.5 | 483 | 29 | 0.057 | dry |
| Clark and Webb chain | 241t 10cwt | 47.5 | 479 | 29 | 0.056 | dry |
| Barker's hydraulic | 210t 2cwt | 50.75 | 516 | 32 | 0.056 | dry |
| Westinghouse vacuum | 204t 3cwt | 52 | 576 | 34.5 | 0.052 | wet |
| Fay mechanical | 186t 3cwt | 44.5 | 388 | 27.5 | 0.057 | wet |
| Steel & McInnes air | 197t 7cwt | 49.5 | 534 | 34.5 | 0.051 | wet |
but for other reasons it was the vacuum system that was generally adopted on UK railways.
Later British practice
In British practice, only passenger trains were fitted with continuous brakes until about 1930; goods and mineral trains ran at slower speed and relied on the brake force from the locomotive and tender and the brake vanBrake van
Brake van and guard's van are terms used mainly in the UK, Australia and India for a railway vehicle equipped with a hand brake which can be applied by the guard...
—a heavy vehicle provided at the rear of the train and occupied by a guard.
Goods and mineral vehicles were provided with hand brakes by which the brakes could be applied by a hand lever operated by staff on the ground. These hand brakes were used where necessary when vehicles were parked but also when these trains needed to descend a steep gradient; the train then stopped before descending and the guard walked forward to pin down the handles of sufficient brakes to give adequate braking effort. Early goods vehicles had brake handles on one side only and random alignment of the vehicles gave the guard sufficient braking but, from about 1930, so-called "either-side" brake handles were provided. These trains, not fitted with continuous brakes were described as "unfitted" trains and they survived in British practice until about 1985. However, from about 1930, semi-fitted trains were introduced, in which some goods vehicles were fitted with continuous brakes and a proportion of such vehicles marshalled next to the locomotive gave sufficient brake power to run at somewhat higher speeds than unfitted trains.
In the early days of diesel locomotive
Diesel locomotive
A diesel locomotive is a type of railroad locomotive in which the prime mover is a diesel engine, a reciprocating engine operating on the Diesel cycle as invented by Dr. Rudolf Diesel...
s, a purpose-built brake tender was attached to the locomotive to increase braking effort when hauling unfitted trains. The brake tender was low, so that the driver could still see the line and signals ahead if the brake tender was propelled (pushed) ahead of the locomotive, which was often the case.
By 1878 there were over 105 patents in various countries for braking systems, most of which were obviously stillborn.
Continuous brakes
As train loads, gradients and speeds increased, braking became a problem. In the late 19th century, significantly better continuous brakes started to appear. The earliest type of continuous brake was the chain brakewhich used a chain, running the length of the train, to operate brakes on all vehicles simultaneously.
The chain brake was soon superseded by air operated
Air brake (rail)
An air brake is a conveyance braking system actuated by compressed air. Modern trains rely upon a fail-safe air brake system that is based upon a design patented by George Westinghouse on March 5, 1872. The Westinghouse Air Brake Company was subsequently organized to manufacture and sell...
or vacuum operated
Vacuum brake
The vacuum brake is a braking system employed on trains and introduced in the mid-1860s. A variant, the automatic vacuum brake system, became almost universal in British train equipment and in those countries influenced by British practice. Vacuum brakes also enjoyed a brief period of adoption in...
brakes. These brakes used hoses connecting all the wagons of a train, so the driver could apply or release the brakes with a single valve in the locomotive.
These continuous brakes can be simple or automatic, the essential difference being what happens should the train break in two. With simple brakes, pressure is needed to apply the brakes, and all braking power is lost if the continuous hose is broken for any reason. Simple non-automatic brakes are thus useless when things really go wrong, as is shown with the Armagh rail disaster
Armagh rail disaster
The Armagh rail disaster happened on 12 June 1889 near Armagh, Ireland when a crowded Sunday school excursion train had to negotiate a steep incline; the steam locomotive was unable to complete the climb and the train stalled. The train crew decided to divide the train and take forward the front...
.
Automatic brakes on the other hand use the air or vacuum pressure to hold the brakes off against a reservoir carried on each vehicle, which applies the brakes if pressure/vacuum is lost in the train pipe. Automatic brakes are thus largely "fail safe", though faulty closure of hose taps can lead to accidents such as the Gare de Lyon accident
Gare de Lyon train accident
The Gare de Lyon rail accident happened on 27 June 1988 when a commuter train inbound to the station Paris-Gare de Lyon crashed into a stationary train killing 56 people.-The disaster:...
.
The standard Westinghouse Air Brake
Westinghouse Air Brake Company
The railway air brake was invented by George Westinghouse of New York state in 1869. Soon after, he moved to Pittsburgh, Pennsylvania, where he established the Westinghouse Air Brake Company on September 28, 1869...
has the additional enhancement of a triple valve, and local reservoirs on each wagon that enable the brakes to be applied fully with only a slight reduction in air pressure, reducing the time that it takes to release the brakes as not all pressure is voided to the atmosphere.
Non-automatic brakes still have a role on engines and first few wagons, as they can be used to control the whole train without having to apply the automatic brakes.
Air versus vacuum brakes
In the early part of the 20th century, many British railways employed vacuum brakeVacuum brake
The vacuum brake is a braking system employed on trains and introduced in the mid-1860s. A variant, the automatic vacuum brake system, became almost universal in British train equipment and in those countries influenced by British practice. Vacuum brakes also enjoyed a brief period of adoption in...
s rather than the air brakes
Air brake (rail)
An air brake is a conveyance braking system actuated by compressed air. Modern trains rely upon a fail-safe air brake system that is based upon a design patented by George Westinghouse on March 5, 1872. The Westinghouse Air Brake Company was subsequently organized to manufacture and sell...
used in America and much of the rest of the world. The main advantage of vacuum was that the vacuum can be created by a steam ejector
Injector
ʎ̩An injector, ejector, steam ejector, steam injector, eductor-jet pump or thermocompressor is a pump-like device that uses the Venturi effect of a converging-diverging nozzle to convert the pressure energy of a motive fluid to velocity energy which creates a low pressure zone that dɯaws in and...
with no moving parts (and which could be powered by the steam of a steam locomotive
Steam locomotive
A steam locomotive is a railway locomotive that produces its power through a steam engine. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine...
), whereas an air brake system requires a noisy and complicated compressor
Gas compressor
A gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume.Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of a gas...
.
However, air brakes can be made much more effective than vacuum brakes for a given size of brake cylinder. An air brake compressor is usually capable of generating a pressure of 90 psi (620.5 kPa) vs only 15 psi (103.4 kPa) for vacuum. With a vacuum system, the maximum pressure differential is atmospheric pressure (14.7 psi or 101.4 kPa at sea level, less at altitude). Therefore, an air brake system can use a much smaller brake cylinder than a vacuum system to generate the same braking force. This advantage of air brakes increases at high altitude, e.g. Peru and Switzerland where today vacuum brakes are used by secondary railways. The much higher effectiveness of air brakes and the demise of the steam locomotive have seen the air brake become ubiquitous; however, vacuum braking is still in use in India, in Argentina and in South Africa, but this will be declining in near future.
Air brake enhancements
One enhancement of the automatic air brake is to have a second air hose (the main reservoir or main line) along the train to recharge the air reservoirs on each wagon. This air pressure can also be used to operate loading and unloading doors on wheat wagonsCovered hopper
A Covered Hopper is a railroad freight car. They are designed for carrying dry bulk loads, varying from grain to products such as sand and clay. The cover protects the loads from the weather - dried cement would be very hard to unload if mixed with water in transit, while grain would be liable to...
and coal and ballast wagons
Hopper car
A hopper car is a type of railroad freight car used to transport loose bulk commodities such as coal, ore, grain, track ballast, and the like. The name originated from the coke manufacturing industry which is part of the steel industry ....
. On passenger coaches, the main reservoir pipe is also used to supply air to operate doors and air suspension.
Electropneumatic brakes
A higher performing EP brake has a train pipe delivering air to all the reservoirs on the train, with the brakes controlled electrically with a 3-wire control circuit. This can give seven levels of braking, from mild to severe, and allows the driver greater control over the level of braking used, which greatly increases passenger comfort. It also allows for faster brake application, as the electrical control signal is propagated effectively instantly to all vehicles in the train, whereas the change in air pressure which activates the brakes in a conventional system can take several seconds or tens of seconds to propagate fully to the rear of the train. This system is not however used on freight trains due to cost.The system adopted on the Southern Region of British Railways in 1950 is more fully described at Electro-pneumatic brake system on British railway trains
Electro-pneumatic brake system on British railway trains
The Electro-pneumatic brake system on British railway trains was introduced in 1950. The Southern Region of British Railways operated an intensive self-contained fleet of electric multiple units for suburban and middle distance passenger trains...
Electronically controlled pneumatic brakes
Electronically controlled pneumatic brakes (ECP) are a development of the late 20th Century to deal with very long and heavy freight trains, and are a development of the EP brake with even higher level of control. In addition, information about the operation of the brakes on each wagon can be returned to the driver's control panel.With ECP, a power and control line is installed from wagon to wagon from the front of the train to the rear. Electrical control signals are propagated effectively instantaneously, as opposed to changes in air pressure which propagate at a rather slow speed limited in practice by the resistance to air flow of the pipework, so that the brakes on all wagons can be applied simultaneously rather than from front to rear. This prevents wagons at the rear "shoving" wagons at the front, and results in reduced stopping distance and less equipment wear.
There are two brands of ECP brakes under development, one by New York Air Brake
New York Air Brake
The New York Air Brake Corporation, located in Watertown, New York, is a manufacturer of air brake and train control systems for the railroad industry worldwide.-History:-Establishment 1876-1900:...
and the other by Wabtec
Wabtec
Wabtec Corporation is an American company formed by the merger of the Westinghouse Air Brake Company and MotivePower Industries Corporation in 1999....
. A single standard is desirable, and it is intended that the two types be interchangeable.
Examples
Reversibility
Brake connections between wagons may be simplified if wagons always point the same way, such as in TasmaniaTasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
. An exception would be made for locomotives which are often turned on turntables or triangles.
On the new Fortescue
Fortescue Metals Group
Fortescue Metals Group is an Australian iron ore mining company. The company has holdings of more than 87,000 km² in the Pilbara region of Western Australia making it the largest tenement holder in the state. It is listed as FMG on the Australian Securities Exchange .In 2008, the group loaded...
railway opened in 2008, wagons are operated in sets, although their direction changes at the balloon loop
Balloon loop
A balloon loop or turning loop allows a rail vehicle or train to reverse direction without having to shunt or even stop. Balloon loops can be useful for passenger trains and unit freight trains, such as coal trains....
at the port. The ECP
Electronically controlled pneumatic brakes
Electronically controlled pneumatic brakes are a type of modern railway braking system which offer improved performance compared to traditional pneumatic brakes.- Overview :...
connections are on one side only and are unidirectional.
Accidents with brakes
- Congo-KinshasaDemocratic Republic of the CongoThe Democratic Republic of the Congo is a state located in Central Africa. It is the second largest country in Africa by area and the eleventh largest in the world...
west of KanangaKanangaKananga, formerly known as Luluabourg or Luluaburg, is the capital of Lulua District in the Democratic Republic of the Congo. It has a population of 1,130,100 ....
(2007) - 100 killed.
- Igandu train disasterIgandu train disasterThe Igandu train disaster was an accident which occurred during the early morning of the 24 June 2002 in the East African country of Tanzania when a large passenger train with over 1,200 people on board rolled backwards down a hill into a stationary goods train, killing 281 people in the worst rail...
, Tanzania (2002) – runaway backwards - 281 killed. - Tenga rail disasterTenga rail disasterThe Tenga rail disaster of May 25, 2002 occurred at Tenga 40 km north-west from Maputo, Mozambique with heavy loss of life; there were 192 deaths and 167 injured.- Overview :...
, Mozambique (2002) – runaway backwards - 192 killed.
- Gare de Lyon train accidentGare de Lyon train accidentThe Gare de Lyon rail accident happened on 27 June 1988 when a commuter train inbound to the station Paris-Gare de Lyon crashed into a stationary train killing 56 people.-The disaster:...
, France (1988) – valve closed by mistake leading to runaway.
- Chapel-en-le-FrithJohn AxonJohn Axon GC was an English train driver from Stockport who died while trying to stop a runaway freight train on a 1 in 58 gradient near Buxton in Derbyshire after a brake failure. The train consisted of an ex-LMS Stanier Class 8F 2-8-0 No...
, Great Britain (1957) – broken steam pipe made it impossible for crew to apply brakes.
- Federal Express , Union station, Washington, DC, (1953) - valve closed by badly designed bufferplate.
- Armagh rail disasterArmagh rail disasterThe Armagh rail disaster happened on 12 June 1889 near Armagh, Ireland when a crowded Sunday school excursion train had to negotiate a steep incline; the steam locomotive was unable to complete the climb and the train stalled. The train crew decided to divide the train and take forward the front...
, Northern Ireland (1889) – runaway backwards led to change in law.
- Shipton-on-Cherwell train crashShipton-on-Cherwell train crashThe Shipton-on-Cherwell train crash was a major disaster which occurred on the Great Western Railway. It involved the derailment of a long passenger train at Shipton-on-Cherwell near Kidlington, Oxfordshire, England, on Christmas Eve, 24 December 1874, and was one of the worst ever disasters on...
, Oxford (1874) - caused by fracture of a carriage wheel.
See also
- Disc brake
- Electromagnetic brakeElectromagnetic brakeAn eddy current brake, like a conventional friction brake, is responsible for slowing an object, such as a train or a roller coaster. However, unlike electro-mechanical brakes, which apply mechanical pressure on two separate objects, eddy current brakes slow an object by creating eddy currents...
- Emergency brake (train)Emergency brake (train)On trains, the expression emergency brake has several meanings:* The maximum brake force available to the driver/engineer from his conventional braking system, usually operated by taking the brake handle to its furthest postion, through a gate mechanism, or by pushing a separate plunger in the cab*...
- Railway air brake
- Regenerative brakeRegenerative brakeA regenerative brake is an energy recovery mechanism which slows a vehicle or object down by converting its kinetic energy into another form, which can be either used immediately or stored until needed...
- Track brakeTrack brakeTrack brakes are a form of brakes unique to railborne vehicles. The braking force derives from the friction resulting from the application of wood or metal braking shoes directly to the tracks...
- Vacuum brakeVacuum brakeThe vacuum brake is a braking system employed on trains and introduced in the mid-1860s. A variant, the automatic vacuum brake system, became almost universal in British train equipment and in those countries influenced by British practice. Vacuum brakes also enjoyed a brief period of adoption in...
- Eddy current brake
Manufacturers
Westinghouse Air Brake CompanyWestinghouse Air Brake Company
The railway air brake was invented by George Westinghouse of New York state in 1869. Soon after, he moved to Pittsburgh, Pennsylvania, where he established the Westinghouse Air Brake Company on September 28, 1869...
(WABCO), later Wabtec
Wabtec
Wabtec Corporation is an American company formed by the merger of the Westinghouse Air Brake Company and MotivePower Industries Corporation in 1999....
Faiveley Transport Knorr-Bremse
Knorr-Bremse
Knorr-Bremse is a manufacturer of braking systems for rail and commercial vehicles that has operated in the field for over 100 years. The company also produces door systems for rail vehicles and torsional dampers. In 2009, the Group's workforce of over 14,000 achieved worldwide sales of EUR 2.761...
Rail Vehicle Systems Westinghouse Brake and Signal Company Ltd
Westinghouse Brake and Signal Company Ltd
The Westinghouse Brake & Signal Company Ltd was created in 1935 when the Westinghouse Brake & Saxby Signal Company Ltd, dropped the 'Saxby' from their title...
(now a division of Knorr-Bremse) New York Air Brake
New York Air Brake
The New York Air Brake Corporation, located in Watertown, New York, is a manufacturer of air brake and train control systems for the railroad industry worldwide.-History:-Establishment 1876-1900:...
(now a division of Knorr-Bremse) MZT HEPOS Mitsubishi Electric
Mitsubishi Electric
is a multinational electronics and information technology company headquartered in Tokyo, Japan. It is one of the core companies of the Mitsubishi Group....
Nabtesco Dellner Aflink Hanning & Kahl GmbH LRT trains, Hydraulic Brakes and control components YUJIN Machinery Ltd
Sources
- British Transport CommissionBritish Transport CommissionThe British Transport Commission was created by Clement Attlee's post-war Labour government as a part of its nationalisation programme, to oversee railways, canals and road freight transport in Great Britain...
, London (1957:142). Handbook for Railway Steam Locomotive Enginemen