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Vacuum Brake
The vacuum brake is a brake, 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 countries influenced by British practice. Vacuum brakes also enjoyed a brief period of adoption in the United States, primarily on narrow-gauge railroads. Their limitations caused them to be progressively superseded by Railway air brake, compressed air systems starting in the United Kingdom from the 1970s onward. The vacuum brake system is now obsolete; it is not in large-scale usage anywhere in the world, other than in South Africa, largely supplanted by railway air brake, air brakes. Introduction In the earliest days of railways, trains were slowed or stopped by the application of manually applied brakes on the locomotive and in brake vehicles through the train, and later by steam power brakes on locomotives. This was clearly unsatisfactory, given the slow and unreliable response ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Servo
A vacuum servo is a component used on motor vehicles in their brake, braking system, to provide assistance to the driver by decreasing the braking effort. In the US it is commonly called a brake booster. A vacuum servo, also known as a power booster or power brake unit, uses a vacuum, usually supplied by the engine, to multiply the driver's pedal effort and apply that effort to the master cylinder. Because the servo depends on the vacuum supplied by a running engine, a check valve is typically used in the vacuum line to maintain residual vacuum without engine support, allowing limited use even after parking. See also *List of auto parts Notes External links What is a brake booster? (a 4-page basic tutorial article, with illustrations & animation) at HowStuffWorks.com Brakes {{Automotive-part-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Check Valve
A check valve, non-return valve, reflux valve, retention valve, foot valve, or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. Check valves are two-port valves, meaning they have two openings in the body, one for fluid to enter and the other for fluid to leave. There are various types of check valves used in a wide variety of applications. Check valves are often part of common household items. Although they are available in a wide range of sizes and costs, check valves generally are very small, simple, and inexpensive. Check valves work automatically and most are not controlled by a person or any external control; accordingly, most do not have any valve handle or stem. The bodies (external shells) of most check valves are made of plastic or metal. An important concept in check valves is the cracking pressure which is the minimum differential upstream pressure between inlet and outlet at which the valve will operate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Davies And Metcalfe
Davies and Metcalfe Ltd is a railway equipment and locomotive manufacturer from Romiley, Manchester, England. It was founded in Aberystwyth in 1878. The company is now owned and run by Richard Charles Metcalfe and they continue to manufacture steam locomotive and traction engine parts from original drawings, as well as modern railway parts worldwide. History Rheidol Foundry James Metcalfe (1847–1920) was apprenticed to Sharp Stewart and worked for the company until 1867 before joining the Manchester and Milford Railway at Aberystwyth as locomotive foreman. Between 1875 and 1877 he took out three patents for an improved exhaust steam injector for steam locomotives and developed it with the financial support of David Davies "Llandinam" and Edward Hamer, the General Manager of the Manchester & Milford Railway. The Patent Exhaust Steam Injector Company was established at the Rheidol Foundry, Aberystwyth in April 1878. Davies and Metcalfe The company later moved to Romiley in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Westinghouse
British Westinghouse Electrical and Manufacturing Company was a subsidiary of the Pittsburgh, US-based Westinghouse Electric and Manufacturing Company. British Westinghouse would become a subsidiary of Metropolitan-Vickers in 1919; and after Metropolitan-Vickers merged with British Thomson-Houston in 1929, it became part of Associated Electrical Industries (AEI) in 1959. Further consolidation saw AEI taken over by GEC in 1967. Establishment George Westinghouse established British Westinghouse in 1899 with capital from his own company and a smaller share from UK investors. The company commenced the construction of its first factory in Trafford Park, Manchester the same year. Manufacturing began in 1902, the same year as the rival British Thomson-Houston (BTH). BTH was majority owned by General Electric and the competition between BTH and British Westinghouse mirrored that of the parent companies, GE and Westinghouse in America. The Belgian electrical engineer, Paul Mossay, worked ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prime Mover (locomotive)
In engineering, a prime mover is an engine that converts chemical energy of a fuel into useful work. In a locomotive, the prime mover is thus the source of power for its propulsion. In an engine-generator set, the engine is the prime mover, as distinct from the generator. Definition In a diesel-mechanical locomotive, the prime mover is the diesel engine that is mechanically coupled to the driving wheels (drivers). In a diesel-hydraulic locomotive, the prime mover is the diesel engine that powers the pumps of one or more torque converters mechanically coupled to the drivers. In a diesel-electric locomotive, the prime mover is the diesel engine that rotates the main generator responsible for producing electricity to power the traction motors that are geared to the drivers. The prime mover can also be a gas turbine instead of a diesel engine. In either case, the generator, traction motors and interconnecting apparatus are considered to be the power transmission system and not p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Railways Mark 2
The Mark 2 family of railway carriages are British Rail's second design of carriages. They were built by British Rail workshops (from 1969 British Rail Engineering Limited (BREL)) between 1964 and 1975 and were of steel construction. Development and production The Mark 2 has a semi-integral construction, giving it more strength than a British Railways Mark 1, Mark 1 in the event of an accident. A key driver of the changed construction method was to overcome the serious corrosion problem point in the Mark 1 at the base of the body, where it was attached to the underframe. Other changes of design, such as the window units, were for the same reason, which had become a serious problem in Mark 1 vehicle maintenance costs. Revised painting methods were also part of this, which coincided with the change of livery from maroon (dark green on the Southern) to the blue and grey that Mark 2 coaches wore for much of their lives (some of the earliest Mark 2 coaches had the old livery at f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Merry-go-round Train
A merry-go-round train, often abbreviated to MGR, is a Unit train, block train of Hopper car, hopper wagons which both loads and unloads its cargo while moving. In the United Kingdom, they are most commonly coal trains delivering to power stations. These trains were introduced in the 1960s, and were one of the few innovations of the Beeching cuts, along with investment from the Central Electricity Generating Board (CEGB) and the NCB (National Coal Board) into new power stations and loading facilities. History and description West Burton Power Station was used as a testing ground for the MGR system but the first power station to receive its coal by MGR was Cockenzie Power Station, Cockenzie in Scotland in 1966. It was estimated at the time that the 80 MGR hoppers needed to feed Cockenzie would replace up to 1,500 conventional wagons. A 1.2 GW power station, such as Cockenzie, receives up to 3 million tons of coal a year, whereas a larger 2 GW plant, like West Burton ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Railways Mark 1
British Rail Mark 1 is the family designation for the first standardised designs of railway carriages built by British Railways (BR) from 1951 until 1974, now used only for charter services on the main lines or on preserved railways. Following nationalisation in 1948, BR had continued to build carriages to the designs of the "Big Four" companies (the Great Western, Southern, London, Midland and Scottish and London and North Eastern railways), and the Mark 1 was intended to be the standard carriage design for use across all lines, incorporating the best features of each of the former companies' designs. It was also designed to be much stronger than previous designs, to provide better protection for passengers in the event of a collision or derailment. The Mark 1 coaches were built in two distinct tranches: the early vehicles (1951–1960) and, from 1961 onwards, the "Commonwealth" stock – so named on account of their bogies, which were a variant of the bogie designed by th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Rail Transport In Great Britain 1948–1994
The history of rail transport in Great Britain 1948–1994 covers the period when the British railway system was nationalised under the name of 'British Railways', latterly known as ''British Rail'' until its eventual privatisation in 1994. The railway system in this period underwent modernisation, reorganisation and rebranding, some of which proved controversial. The use of steam locomotives on the network also ended in this period. Due to falling passenger numbers, rail subsidies from the government were necessary to keep the railways financially viable. Concerns about the levels of these contributed to the Beeching cuts that closed down many less well used lines. The 1940s: Nationalisation The Transport Act 1947 nationalised nearly all forms of mass transport in Great Britain and came into effect on 1 January 1948. British Railways came into existence as the business name of the Railway Executive of the British Transport Commission (BTC) on 1 January 1948 when it took over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Locomotive
An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or on-board energy storage such as a Battery (electricity), battery or a supercapacitor. Locomotives with on-board fuelled prime mover (locomotive), prime movers, such as diesel engines or gas turbines, are classed as Diesel–electric powertrain, diesel–electric or turbine–electric powertrain, gas turbine–electric and not as electric locomotives, because the electric generator/motor combination serves only as a Transmission (mechanics), power transmission system. Electric locomotives benefit from the high efficiency of electric motors, often above 90% (not including the inefficiency of generating the electricity). Additional efficiency can be gained from regenerative braking, which allows kinetic energy to be recovered during braking to put power back on the line. Newer electric locomotives use AC motor-inverter drive systems that provide for regenerative braking. Electric loco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Locomotive
A diesel locomotive is a type of railway locomotive in which the prime mover (locomotive), power source is a diesel engine. Several types of diesel locomotives have been developed, differing mainly in the means by which mechanical power is conveyed to the driving wheels. The most common are diesel–electric locomotives and diesel–hydraulic. Early internal combustion engine, internal combustion locomotives and railcars used kerosene and gasoline as their fuel. Rudolf Diesel patented his first compression-ignition engine in 1898, and steady improvements to the design of diesel engines reduced their physical size and improved their power-to-weight ratios to a point where one could be mounted in a locomotive. Internal combustion engines only operate efficiently within a limited power band, and while low-power gasoline engines could be coupled to mechanical transmission (mechanics), transmissions, the more powerful diesel engines required the development of new forms of transmiss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double Heading
In railroad terminology, double heading indicates the use of two locomotives at the front of a train, each operated individually by its own crew. The practice of triple-heading involves the use of three locomotives. The practice of multi-heading involves the use of multiple locomotives and so on. Double heading is most common with steam locomotives, but is also practised with diesel locomotives. It is not strictly the same practice as two or more diesel or electric locomotives working ' in multiple' (or 'multiple-working'), where both (or all) locomotives are controlled by a single driver in the cab of the leading locomotive. Advantages Double heading is practised for a number of reasons: * In the UK it was usually to gain traction on steep inclines, twice the amount of driven wheels – twice the amount of grip. * The need for additional motive power when a single locomotive is unable to haul the train due to uphill grades, excessive train weight, or a combination of the tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
