Propelling Control Vehicle
A Propelling Control Vehicle is a type of British railway carriage for carrying mail. They were converted from Class 307 driving trailers and have a cab at one end which allows slow-speed movement control. PCVs are unpowered but the controls allow mail trains to be reversed at low speed, using the power of the locomotive at the other end of the train. Similar BR Class 91 Driving Van Trailer used on the ECML differ by being equipped for high-speed train control. Forty-two PCVs were converted by Hunslet-Barclay in Kilmarnock from 1994 to 1996; the rebuilding work including removal of the windows and slam-doors, the fitting of roller shutter doors, modernisation of the cab. The vehicles were given the TOPS code NAA and numbered 94300–94327 and 94331–94345; the first two vehicles converted were prototypes, were extensively tested to iron out any problems. The subsequent 40 vehicles incorporated modifications as a result of this testing. At the same time these vehicles were converted, the Class 47/7 locomotives that hauled mail trains were modified to be able to work in push-pull mode with the PCVs.
When first converted the vehicles were used by the Rail Express Systems parcels sector of British Rail. They were painted in Rail Express Systems red/grey livery with light blue flashes. PCVs were marshalled at either end of mail trains that worked into London termini, which removed the need for the locomotive to run round the train at its destination. Trains were propelled only at low speed, not for long distances. In 1996 Rail Express Systems was sold to EWS, who continued to operate mail trains on behalf of Royal Mail. PCVs were used on trains between London and Norwich, Bristol, Swansea and Glasgow. PCVs were used on Travelling Post Office trains from London to Plymouth, Norwich and Glasgow; the two prototype PCVs, nos. 94300/1, were non-standard. They were used as standard mail coaches on a new high-speed mail train from Walsall to Inverness, painted in EWS maroon/gold livery and renumbered 95300/1. In early 2004, EWS lost the contract to transport mail; as a result, all PCVs except 95300/1 were withdrawn from service, pending new traffic, sale or scrapping.
After a limited amount of residual traffic, trials for possible use for the movement of secure goods, 95300 and 95301 were withdrawn. During September 2016 95301 moved into preservation; the table below shows details including numbering and disposition. Control car - a passenger car with a train control cab used in push-pull service
In rail transport, head-end power known as electric train supply is the electrical power distribution system on a passenger train. The power source a locomotive at the front or'head' of a train, provides the electricity used for heating, lighting and other'hotel' needs; the maritime equivalent is hotel electric power. A successful attempt by the London and South Coast Railway in October 1881 to light the passenger car between London and Brighton heralded the beginning of using electricity to light trains in the world. Oil lamps were introduced in 1842 to light trains. Economics drove the Lancashire and Yorkshire Railway to replace oil with coal gas lighting in 1870, but a gas cylinder explosion on the train led them to abandon the experiment. Oil-gas lighting was introduced in late 1870. Electrical lighting was introduced in October 1881 by using twelve Swan carbon filament incandescent lamps connected to an underslung battery of 32 Faure lead-acid rechargeable cells, suitable for about 6 hours lighting before being removed for recharging.
The North British Railway in 1881 generated electricity using a dynamo on the Brotherhood steam locomotive to provide electrical lighting in a train, a concept, called head-end power. High steam consumption led to abandonment of the system. Three trains were started in 1883 by London and South Coast Railway with electricity generated on board using a dynamo driven from one of the axles; this charged a lead-acid battery in the guard's van, the guard operated and maintained the equipment. The system provided electric lighting in the train. In 1887, steam-driven generators in the baggage cars of the Florida Special and the Chicago Limited trains in the US supplied electric lighting to all the cars of the train by wiring them, to introduce the other form of head-end power; the oil-gas lighting provided a higher intensity of light compared to electric lighting and was more popularly used till September 1913, when an accident on the Midland Railway at Aisgill caused a large number of passenger deaths.
This accident prompted railways to adopt electricity for lighting the trains. Throughout the remainder of the age of steam and into the early diesel era, passenger cars were heated by low pressure saturated steam supplied by the locomotive, with the electricity for car lighting and ventilation being derived from batteries charged by axle-driven generators on each car, or from engine-generator sets mounted under the carbody. Starting in the 1930s, air conditioning became available on railcars, with the energy to run them being provided by mechanical power take offs from the axle, small dedicated engines or propane; the resulting separate systems of lighting power, steam heat, engine-driven air conditioning, increased the maintenance workload as well as parts proliferation. Head-end power would allow for a single power source to handle all those functions, more, for an entire train. In the steam era, all cars in Finland and Russia had a coal fired fireplace; such a solution was considered a fire danger in most countries in Europe, but not in Russia.
Trains hauled by a steam locomotive would be provided with a supply of steam from the locomotive for heating the carriages. When diesel locomotives and electric locomotives replaced steam, the steam heating was supplied by a steam-heat boiler; this was heated by an electric element. Oil-fired steam-heat boilers were unreliable, they caused more locomotive failures on any class to which they were fitted than any other system or component of the locomotive, this was a major incentive to adopt a more reliable method of carriage heating. At this time, lighting was powered by batteries which were charged by a dynamo underneath each carriage when the train was in motion, buffet cars would use bottled gas for cooking and water heating. Diesels and electric locomotives were equipped with Electric Train Heating apparatus, which supplied electrical power to the carriages to run electric heating elements installed alongside the steam-heat apparatus, retained for use with older locomotives. Carriage designs abolished the steam-heat apparatus, made use of the ETH supply for heating, ventilation, air conditioning, fans and kitchen equipment in the train.
In recognition of this ETH was renamed Electric Train Supply. Each coach has an index relating to the maximum consumption of electricity; the sum of all the indices must not exceed the index of the locomotive. One "ETH index unit" equals 5 kW; the first advance over the old axle generator system was developed on the Boston and Maine Railroad, which had placed a number of steam locomotives and passenger cars into dedicated commuter service in Boston. Due to the low average speeds and frequent stops characteristic of a commuter operation, the axle generators' output was insufficient to keep the batteries charged, resulting in passenger complaints about lighting and ventilation failures. In response, the railroad installed higher capacity generators on the locomotives assigned to these trains, provided electrical connections to the cars; the cars used steam from the locomotive for heating. Some early diesel streamliners took advantage of their fixed-consist construction to employ electrically-powered lighting, air conditioning, heating.
As the cars were not meant to mix with existing passenger stock, compatibility of these systems was not a concern. For example, the Nebraska Zephyr trainset has three diesel generator sets in the first car to power onboard equipment; when diese
InterCity (British Rail)
InterCity was introduced by British Rail in 1966 as a brand-name for its long-haul express passenger services. In 1986 the British Railways Board divided its operations into a number of sectors; the sector responsible for long-distance express trains assumed the brand-name InterCity, although many routes that were operated as InterCity services were assigned to other sectors. British Rail first used the term Inter-City in 1950 as the name of a train running between London Paddington and Wolverhampton Low Level; this was part of an overall policy of introducing new train names in the post World War II period. The name was applied to the business express which ran from London in the morning and returned in the afternoon, became part of the railway lore of the West Midlands. West Midlands residents always believed that it was the success of this one train that led to the adoption of the name as a British Rail brand in 1966; this belief was supported by the timeline: in 1966 The Inter-City was heading towards its ultimate demise in 1967, when the mainline London-West Midlands service was consolidated into the newly electrified route via Rugby.
Following sectorisation of British Rail, InterCity became profitable. InterCity became one of Britain’s top 150 companies, providing city centre to city centre travel across the nation from Aberdeen and Inverness in the north to Poole and Penzance in the south. InterCity had the following divisions: East Coast: Services on the East Coast Main Line from London King's Cross to Yorkshire, North East England and eastern Scotland. West Coast: Services on the West Coast Main Line from London Euston to the West Midlands, North Wales, North West England and southern Scotland, including overnight sleeper services to Scotland. Midland: Services on the Midland Main Line from London St Pancras to the East Midlands and South Yorkshire. Great Western: Services on the Great Western Main Line from London Paddington to South Wales and the West Country, including overnight sleeper services to the West Country. Great Eastern: Services on the Great Eastern Main Line from London Liverpool Street to Essex and East Anglia.
Cross-Country: Services between city pairs that used a combination of the various main lines, but avoided Greater London. Gatwick Express: Shuttle service between London Victoria and Gatwick Airport; the InterCity sector was responsible for Motorail services to and from London Kensington Olympia. InterCity operated High Speed Trains under the brand-name InterCity 125, as well as InterCity 225s for the electric high-speed trains operated on the East Coast route; the "125" referred to the trains' top speed in miles per hour, equivalent to 201 km/h, whereas "225" referred to the intended top speed in km/h and for signalling reasons their actual speed limit was the same 125 mph. InterCity 250 was the name given by InterCity to the proposed upgrade of the West Coast Main Line in the early 1990s; the existing trains operating on the West Coast were intended to be marketed under the brand InterCity 175, again referring to those trains' top operating speed of 110 mph equivalent to 175 km/h, although this idea was subsequently dropped.
All InterCity day services ran with a buffet car and the majority ran at speeds of 100 mph or above. If expresses on other sectors are included, there was a period in the early 1990s when British Rail operated more 100 mph services per day than any other country. Special discounted fares, including the Super Advance and the APEX, were available on InterCity if booked ahead. HST services were first introduced in 1976 on the Great Western Main Line from London Paddington to Bristol and Swansea. Formations consisted of 2 first-class, a Restaurant Buffet and 4 standard-class Mark 3 carriages with a Class 43 power car at each end. East Coast – InterCity 125 HST services started in 1977: Typically 2 first-class, a Restaurant Kitchen, Buffet Standard and 4 standard-class British Rail Mark 3 carriages with a Class 43 power car at each end; these progressively replaced Class 55 "Deltics" which were withdrawn in 1981. As catering needs changed, the Restaurant Kitchen was replaced by a fifth standard-class coach.
InterCity 225: a Class 91 electric locomotive, nine Mark 4 coaches and a Driving Van Trailer operating in push-pull mode. This saw most of the HSTs transferred to Great Western and Cross-Country routes but some remained for the runs to/from Aberdeen and Inverness. West Coast – London Euston to Wolverhampton used Class 86 electric locomotives hauling Mark 2 carriages and operated at 100 mph. Euston to Glasgow services used Class 87 and Class 90 locomotives hauling Mark 3 coaches and operated at 110 mph. Euston to Holyhead services used. From 1988, West Coast trains operated in push-pull mode with a DVT at the London end of the train. Before DVTs were introduced, larger fleets of Classes 81–87 were used to haul the trains conventionally. Class 50s operated in pairs north of Preston until electrification was completed in 1974. Great Western – Intercity 125s from new, which replaced Class 52s. Services were operated by Mark 2 carriages hauled by Class 47s and 50s. Anglia – Class 86 electrics hauling Mark 1 and Mark 2 carriages using Mark 2 Driving Brake Standard Opens in push-pull mode.
Class 47s were used before electrification in 1987. Some routes transferred to Network SouthEast, leaving London-Norwic
Rail Express Systems
Rail Express Systems was a sector of British Rail. Upon the sectorisation of British Rail during the 1980s, the Parcels Sector was created. In 1991, this was re-branded as Rail Express Systems; this sector of British Rail was responsible for transport of mail and parcels traffic, including the Travelling Post Office trains, as well as taking over the charter operations from Intercity. The Rail Express Systems launch event was held at Crewe Diesel Depot in October 1991. For this event, examples of Class 08, 47, 86 and 90 locomotives were painted into a new livery of red, with a grey upper band, light blue and grey flashes; the light blue and grey flashes represent a set of stylised eagle's wings. The sector had maintenance depots at Crewe Diesel, Bristol Barton Hill and Euston Downside. Rolling stock was maintained by other sectors at Heaton depot in Newcastle and Liverpool Edge Hill. During the existence of the Parcels sector there were many changes in the use of rail to deliver mail and parcels.
Smaller services were cut back, mail services were removed from most passenger stations. These changes were in part through the Railnet scheme initiated in 1996 which created mail hubs at Shieldmuir, Low Fell, Doncaster, Bristol Parkway and Wembley PRDC as well as dedicated platforms at Stafford; the company was bought by English Welsh & Scottish in 1996. The late 1980s and early 1990s saw many changes to the Rail Express Systems fleet, with the cessation of the usage of Class 105s by 1987, Class 114s by 1990, Class 120s by 1987, Class 127s by 1989, Class 128s by 1990, Class 302s by 1996 and Class 308s by 1989. In the same period, Class 325 EMUs were introduced and the entire parcels and mails fleet was refurbished or withdrawn. Rail Magazine Issue 159 Motive Power Pocket books pub. Platform 5 British Multiple Units Volume 1 and Volume 3
25 kV AC railway electrification
Railway electrification systems using alternating current at 25 kilovolts are used worldwide for high-speed rail. This electrification is ideal for railways that carry heavy traffic. After some experimentation before World War II in Hungary and in the Black Forest in Germany, it came into widespread use in the 1950s. One of the reasons why it was not introduced earlier was the lack of suitable small and lightweight control and rectification equipment before the development of solid-state rectifiers and related technology. Another reason was the increased clearance distances required where it ran under bridges and in tunnels, which would have required major civil engineering in order to provide the increased clearance to live parts. Railways using older, lower-capacity direct current systems have introduced or are introducing 25 kV AC instead of 3 kV DC/1.5 kV DC for their new high-speed lines. The first successful operational and regular use of the 50 Hz system dates back to 1931, tests having run since 1922.
It was developed by Kálmán Kandó in Hungary, who used 16 kV AC at 50 Hz, asynchronous traction, an adjustable number of poles. The first electrified line for testing was Budapest–Dunakeszi–Alag; the first electrified line was Budapest–Győr–Hegyeshalom. Although Kandó's solution showed a way for the future, railway operators outside of Hungary showed a lack of interest in the design; the first railway to use this system was completed in 1936 by the Deutsche Reichsbahn who electrified part of the Höllentalbahn between Freiburg and Neustadt installing a 20 kV, 50 Hz AC system. This part of Germany was in the French zone of occupation after 1945; as a result of examining the German system in 1951 the SNCF electrified the line between Aix-les-Bains and La Roche-sur-Foron in southern France at using the same 20 kV but converted to 25 kV in 1953. The 25 kV system was adopted as standard in France, but since substantial amounts of mileage south of Paris had been electrified at 1,500 V DC, SNCF continued some major new DC electrification projects, until dual-voltage locomotives were developed in the 1960s.
The main reason why electrification at this voltage had not been used before was the lack of reliability of mercury-arc-type rectifiers that could fit on the train. This in turn related to the requirement to use DC series motors, which required the current to be converted from AC to DC and for that a rectifier is needed; until the early 1950s, mercury-arc rectifiers were difficult to operate in ideal conditions and were therefore unsuitable for use in railway locomotives. It was possible to use AC motors, but they have less than ideal characteristics for traction purposes; this is because control of speed is difficult without varying the frequency and reliance on voltage to control speed gives a torque at any given speed, not ideal. This is why DC series motors are the best choice for traction purposes, as they can be controlled by voltage, have an ideal torque vs speed characteristic. In the 1990s, high-speed trains began to use lighter, lower-maintenance three-phase AC induction motors; the N700 Shinkansen uses a three-level converter to convert 25 kV single-phase AC to 1,520 V AC to 3,000 V DC to a maximum 2,300 V three-phase AC to run the motors.
The system works in reverse for regenerative braking. The choice of 25 kV was related to the efficiency of power transmission as a function of voltage and cost, not based on a neat and tidy ratio of the supply voltage. For a given power level, a higher voltage allows for a lower current and better efficiency at the greater cost for high-voltage equipment, it was found that 25 kV was an optimal point, where a higher voltage would still improve efficiency but not by a significant amount in relation to the higher costs incurred by the need for larger insulators and greater clearance from structures. To avoid short circuits, the high voltage must be protected from moisture. Weather events, such as "the wrong type of snow", have caused failures in the past. An example of atmospheric causes occurred in December 2009, when four Eurostar trains broke down inside the Channel Tunnel. Electric power from a generating station is transmitted to grid substations using a three-phase distribution system. At the grid substation, a step-down transformer is connected across two of the three phases of the high-voltage supply.
The transformer lowers the voltage to 25 kV, supplied to a railway feeder station located beside the tracks. SVCs are used for voltage control. In some cases dedicated single-phase AC power lines were built to substations with single phase AC transformers; such lines were built to supply the French TGV. Railway electrification using 25 kV, 50 Hz AC has become an international standard. There are two main standards that define the voltages of the system: EN 50163:2004+A1:2007 - "Railway applications. Supply voltages of traction systems" IEC 60850 - "Railway Applications. Supply voltages of traction systems"The permissible range of voltages allowed are as stated in the above standards and take into account the number of trains drawing current and their distance from the substation; this system is now part of the European Union's Trans-European railway interoperability standards. Systems based on this standard but with some variations have been used. In countries where 60 Hz is the normal gr
A railway brake is a type of brake used on the cars of railway trains to enable deceleration, control acceleration or to keep them immobile 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 used on trains. 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 brakemen, 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, 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, who had access to a brake wheel at their posts, supplanted them. The braking effort achievable was limited and it was unreliable, as the application of brakes by guards depended upon their hearing and responding to a whistle for brakes. 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; as train speeds increased, it became essential to provide some more powerful braking system capable of instant application and release by the train operator, 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 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 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 45½ to 48½ 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 Trials conducted after Abbots Ripton reported the following 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, because of the necessity to add and remove vehicles from the train at frequent points on the journey.. The chief types of solution were: A spring system: James Newall, carriage builder to the Lancashire and Yorkshire Railway, in 1853 obtained a patent for a system whereby a rotating rod passing the length of the train was used to wind up the brake levers on each carriage against the force of conical springs carried in cylinders.
The rod, mounted on the carriage roofs in rubber journals, was fitted with universal joints and short sliding sections to allow for compression of the buffers. The brakes were controlled from one end of the train; the guard wound up the rod, to release the brakes. When the ratchet was released the springs applied the brakes. If the train divided, the brakes were not held off by the ratchet in the guard's compartment and the springs in each carriage forced the brakes onto the wheel. Excess play in the couplings limited the effectiveness of the device to about five carriages; this apparatus was sold to a few companies and the system received recommendation from the Board of Trade. The L&Y conducted a simultaneous trial with a similar system designed by another employee, Charles Fay, but little difference was found in their effectiveness. In Fay's version, patented in 1856, the rods passed beneath the carriages and the spring application, which offered the important "automatic" feature of Newall but could act too fiercely, was replaced by a worm and rack for each brake.
The chain brake, such as the Heberlein brake, 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. Hydraulic brakes; as with car brakes. These found some favor in the UK, but water was used as the hydraulic fluid and in the UK "Freezing possibilities told against the hydraulic brakes, though the Great Eastern Railway, which used them for a while, overcame this by the use of salt water" 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 cheap and effective, but it had the major weakness that it became inoperative if the train became divided or if the tra