Advanced Passenger Train
Encyclopedia
Tilting train
A tilting train is a train that has a mechanism enabling increased speed on regular rail tracks. As a train rounds a curve at speed, objects inside the train experience centrifugal force. This can cause packages to slide about or seated passengers to feel squashed by the outboard armrest due to...
High Speed Train
High Speed Train
There are three types of trains in Britain that have been traditionally viewed as high speed trains:* Advanced Passenger Train - Tilting trains which never entered into regular revenue-earning service....
developed by British Rail
British Rail
British Railways , which from 1965 traded as British Rail, was the operator of most of the rail transport in Great Britain between 1948 and 1997. It was formed from the nationalisation of the "Big Four" British railway companies and lasted until the gradual privatisation of British Rail, in stages...
during the 1970s and early 1980s.
The introduction into service of the Advanced Passenger Train was to be a three-stage project. Phase 1, the development of an experimental APT, the APT-E
British Rail APT-E
The APT-E, for Advanced Passenger Train Experimental, was the prototype Advanced Passenger Train tilting train unit. It was powered by gas turbines, the only multiple unit so powered that was used by British Rail. The APT-E consisted of two driving power cars and two trailer cars...
, was completed. Phase 2, the introduction of three prototype trains, known as the APT-P
British Rail Class 370
British Rail's Class 370 tilting trains, also referred to as APT-P , were the pre-production Advanced Passenger Train units...
, into revenue service on the Glasgow - London route, did occur but enjoyed limited service due to bad publicity. Phase 3, the introduction of the Squadron fleet designated APT-S, did not occur. The knowledge and experience gained enabled the construction of other high speed trains, including tilting
Tilting train
A tilting train is a train that has a mechanism enabling increased speed on regular rail tracks. As a train rounds a curve at speed, objects inside the train experience centrifugal force. This can cause packages to slide about or seated passengers to feel squashed by the outboard armrest due to...
derivatives.
Background
In the mid to late 20th century, British Rail express services compared unfavourably with France's TGVTGV
The TGV is France's high-speed rail service, currently operated by SNCF Voyages, the long-distance rail branch of SNCF, the French national rail operator....
and Japan's Shinkansen
Shinkansen
The , also known as THE BULLET TRAIN, is a network of high-speed railway lines in Japan operated by four Japan Railways Group companies. Starting with the Tōkaidō Shinkansen in 1964, the network has expanded to currently consist of of lines with maximum speeds of , of Mini-shinkansen with a...
. Experience with High Speed Trains on the East Coast Main Line
East Coast Main Line
The East Coast Main Line is a long electrified high-speed railway link between London, Peterborough, Doncaster, Wakefield, Leeds, York, Darlington, Newcastle and Edinburgh...
from London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
to Edinburgh
Edinburgh
Edinburgh is the capital city of Scotland, the second largest city in Scotland, and the eighth most populous in the United Kingdom. The City of Edinburgh Council governs one of Scotland's 32 local government council areas. The council area includes urban Edinburgh and a rural area...
had shown that reduced journey times could produce a significant increase in passenger numbers, but that line was largely straight and suited to high speeds. Other lines, such as the West Coast Main Line
West Coast Main Line
The West Coast Main Line is the busiest mixed-traffic railway route in Britain, being the country's most important rail backbone in terms of population served. Fast, long-distance inter-city passenger services are provided between London, the West Midlands, the North West, North Wales and the...
(WCML) from London to Glasgow
Glasgow
Glasgow is the largest city in Scotland and third most populous in the United Kingdom. The city is situated on the River Clyde in the country's west central lowlands...
, were not straight enough to support high speeds with conventional equipment. Lateral forces would be just too high around corners; passengers would not be able to stand upright easily, and items would move on tables. Because slower trains also use the same tracks, superelevation (banking or "canting" of the track around curves) could only be utilised to enable speeds up to 125 mph (56 m/s).
In order to permit a top speed of 155 mph (69 m/s), and thereby cut journey times, British Rail
British Rail
British Railways , which from 1965 traded as British Rail, was the operator of most of the rail transport in Great Britain between 1948 and 1997. It was formed from the nationalisation of the "Big Four" British railway companies and lasted until the gradual privatisation of British Rail, in stages...
's engineers at the Derby Research Division
British Rail Research Division
The British Rail Research Division came into being in 1964 directly under the control of the British Railways Board, moving into purpose-built premises at the Railway Technical Centre in Derby. The intention was to improve railway reliability and efficiency, while reducing costs and improving revenue...
developed an advanced active tilting technology, using hydraulic rams controlled by spirit level sensors to tilt the passenger cars into the curves so that no lateral forces would be felt. Numerous engineers involved in the project had an aeroengineering background. Not only was the train designed to tilt but it was also articulated and had hydrokinetic (Water turbine) brakes. The latter feature is often overlooked but was in fact just as significant as the tilting concept, because it enabled the train to stop within the existing signal spacings. The fact that under operating conditions it failed to do so, was one of the main factors in the train being withdrawn.
Some of the senior managers in British Rail at the time were unwilling to put all their eggs in one basket, and so initiated a parallel project to design a train based on conventional technology as a stopgap. This was the High Speed Train (HST), which was also marketed under the InterCity 125
InterCity 125
The InterCity 125 was the brand name of British Rail's High Speed Train fleet. The InterCity 125 train is made up of two power cars, one at each end of a fixed formation of Mark 3 carriages, and is capable of , making the train the fastest diesel-powered locomotive in regular service in the...
name. The HST went on to become one of the most successful designs ever and is still in use 30 years later.
In 1972, the APT-E
British Rail APT-E
The APT-E, for Advanced Passenger Train Experimental, was the prototype Advanced Passenger Train tilting train unit. It was powered by gas turbines, the only multiple unit so powered that was used by British Rail. The APT-E consisted of two driving power cars and two trailer cars...
, a gas turbine-powered
Gas turbine-electric locomotive
A gas turbine - electric locomotive, or GTEL, is a locomotive that uses a gas turbine to drive an electric generator or alternator. The electric current thus produced is used to power traction motors. This type of locomotive was first experimented with during the Second World War, but reached its...
experimental testbed, was constructed. This was only four cars in length; two power cars, one at each end and two 'passenger' cars full of instrumentation. The experimental train APT-E having proved the concept, British Rail moved to build three prototype Class 370 APT-P
British Rail Class 370
British Rail's Class 370 tilting trains, also referred to as APT-P , were the pre-production Advanced Passenger Train units...
trains. Gas turbine
Gas turbine
A gas turbine, also called a combustion turbine, is a type of internal combustion engine. It has an upstream rotating compressor coupled to a downstream turbine, and a combustion chamber in-between....
s had been chosen for their light weight compared to diesel engines but Leyland had ceased production and development and no other was suitable. Thus the new APT-P and APT-S trains were to be electrically powered and so restricted to electrified track.
The APT-P trains were designed as two half-trains with twin power cars in the middle, sharing one pantograph. There was a passage through the power cars but it was noisy, cramped and not normally permitted for passengers. Therefore, each end of the train had to duplicate facilities. There were a number of reasons for this design compromise. Two power cars were necessary to maintain the design speeds over the northern banks with 12 coaches. Normally these would be situated at the front and rear of the train (as with the HST and TGV etc.) but, due to the design of the overhead line, a "wave" was set up in it by the front pantograph, thus causing problems for current collection from the rear unit. The obvious answer was an on-board 25 kV link to the rear power car but this was considered infeasible at the time. The final option was to put both power cars at one end of the train but, at the high speeds (and with the tilt feature), concerns were raised over excessive buckling forces when the train was being propelled.
Demise
Members of the press riding the first demonstration train apparently reported high levels of motion sickness and this caused much bad publicity; though it has been suggested by some, including APT designer Prof. Alan Wickens, that the 'motion sickness' suffered by the press may have had more to do with them over-indulging in BR's "liquid hospitality". None of the other passengers on this demonstration run or subsequent runs, noticed the problem. It turned out that the tilting mechanism was, in effect, working too well. It was perfectly compensating for lateral forces around curves, which induced motion sickness, since the eyes could see turning but the body did not feel it; reducing the tilt by a few degrees so that the curves could be felt cured this.
On one test run with the press, certain units of the train 'stuck' tilted to one side for parts of the journey.
The first "public" APT-P run on 7 December 1981, from Glasgow Central to London Euston
Euston railway station
Euston railway station, also known as London Euston, is a central London railway terminus in the London Borough of Camden. It is the sixth busiest rail terminal in London . It is one of 18 railway stations managed by Network Rail, and is the southern terminus of the West Coast Main Line...
, was successful. Even so, British Rail played safe by running a scheduled service out of Glasgow some 15 minutes later. Some APT-P cars suffered tilt failures during the return trip out of London and this was widely publicised by the media
Mass media
Mass media refers collectively to all media technologies which are intended to reach a large audience via mass communication. Broadcast media transmit their information electronically and comprise of television, film and radio, movies, CDs, DVDs and some other gadgets like cameras or video consoles...
. The extremely cold weather also caused problems with the brakes freezing. The trains were withdrawn from revenue service four days later. This highly visible failure was eventually to prove terminal for the project.
The APT-P trains were quietly reintroduced into service in mid-1984 and ran regularly, the problems having been apparently corrected but the political and managerial will to continue the project and build the projected APT-S production vehicles had evaporated.
One APT-P set was kept at Glasgow Shields Depot and found use once or twice as an "EMU
Multiple unit
The term multiple unit or MU is used to describe a self-propelled carriages capable of coupling with other units of the same or similar type and still being controlled from one driving cab. The term is commonly used to denote passenger trainsets consisting of more than one carriage...
" to take journalists from Glasgow Central to Anderston railway station
Anderston railway station
Anderston railway station serves Glasgow's Financial district of Anderston and, across the M8 motorway, the housing schemes of Anderston West. It is a manned station with an island platform and most of it is underground.- History :...
and back, for the Scottish Exhibition and Conference Centre
Scottish Exhibition and Conference Centre
The Scottish Exhibition and Conference Centre , located on the north bank of the River Clyde, in Glasgow, is Scotland's largest exhibition centre....
. A second APT-P was stored in a siding behind Crewe Works. The "Glasgow" APT-P and the third APT-P were scrapped very quietly without publicity.
Williams notes that work continued on a new variant, the APT-U, and that the project was later retitled InterCity 225
InterCity 225
The InterCity 225 is a locomotive-hauled domestic train in the United Kingdom, comprising a Class 91 electric locomotive, nine Mark 4 coaches and a Driving Van Trailer...
, perhaps to distance it from the bad publicity surrounding the APT-P. The Mark 4
British Rail Mark 4
British Rail's fourth design of passenger carriages was designated Mark 4, designed for use in InterCity 225 sets on the newly-electrified East Coast Main Line between London, Leeds, and Edinburgh.-History and construction:...
coach design that was introduced as part of the new IC225 sets for the East Coast Main Line
East Coast Main Line
The East Coast Main Line is a long electrified high-speed railway link between London, Peterborough, Doncaster, Wakefield, Leeds, York, Darlington, Newcastle and Edinburgh...
electrification is a direct descendant of the APT-U, and the coach was designed for the retrofitting of the tilt mechanism, although this was never implemented. The Class 91
British Rail Class 91
The British Rail Class 91 is a class of , electric locomotives ordered as a component of the East Coast Main Line modernisation and electrification programme of the late 1980s. The Class 91s were given the auxiliary name of InterCity 225 to indicate their envisaged top speed of...
locomotives that power the IC225s also take many features from the APT-P powercars, including body- rather than bogie-mounted traction motors to reduce unsprung load and having the transformer below rather than on top of the underframe to reduce the centre of gravity. Unlike the APT-P powercars, though, they were never intended to tilt.
APT today
National Railway Museum
The National Railway Museum is a museum in York forming part of the British National Museum of Science and Industry and telling the story of rail transport in Britain and its impact on society. It has won many awards, including the European Museum of the Year Award in 2001...
and is on display at their Locomotion
Shildon Locomotion Museum
Shildon Locomotion Museum is a railway museum in Shildon, County Durham, England. The museum is a branch of the National Railway Museum , which is part of the National Museum of Science and Industry...
museum at Shildon
Shildon
Shildon is a town in County Durham, in England. It is situated 2 miles to the south east of Bishop Auckland and 11 miles north of Darlington. It is 13 miles away from Durham, 23 miles from Sunderland and 23 miles from Newcastle-upon-Tyne...
in County Durham
County Durham
County Durham is a ceremonial county and unitary district in north east England. The county town is Durham. The largest settlement in the ceremonial county is the town of Darlington...
. Also at Locomotion is an APT-P power car, number 49006, which is due to undergo restoration work after having been stored outdoors at York
York
York is a walled city, situated at the confluence of the Rivers Ouse and Foss in North Yorkshire, England. The city has a rich heritage and has provided the backdrop to major political events throughout much of its two millennia of existence...
for many years. Appropriately, the second APT-P unit is now on display at Crewe Heritage Centre (formerly known as The Railway Age) and can be seen from trains passing on the adjacent WCML
WCML
WCML may refer to:* West Coast Main Line, a mainline railway in the United Kingdom* WCML , a television station licensed to Alpena, Michigan, United States...
.
APT versus TGV and Shinkansen
In contrast to the APT, FranceFrance
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
's high speed train, the TGV
TGV
The TGV is France's high-speed rail service, currently operated by SNCF Voyages, the long-distance rail branch of SNCF, the French national rail operator....
, developed around the same time, has been a great success. SNCF
SNCF
The SNCF , is France's national state-owned railway company. SNCF operates the country's national rail services, including the TGV, France's high-speed rail network...
decided to develop not only a new train, but a new infrastructure for it to run upon as well. They built completely new Lignes à Grande Vitesse (high speed lines) with long, straight tracks designed for high-speed running, with longer signalling blocks lengths which relieved the problems of braking in adverse conditions, and avoiding the need for a complicated tilting system, as did the Japanese with their Shinkansen
Shinkansen
The , also known as THE BULLET TRAIN, is a network of high-speed railway lines in Japan operated by four Japan Railways Group companies. Starting with the Tōkaidō Shinkansen in 1964, the network has expanded to currently consist of of lines with maximum speeds of , of Mini-shinkansen with a...
.
Doing this in Britain has involved more red tape, with public enquiries necessary, as shown with the initial difficulty in obtaining permission to build High Speed 1. In Britain's crowded island, the cost and upheaval present a significant obstacle in the construction of new lines (and not politically acceptable, as it was in the even more crowded Japan), particularly as British Rail was looking for a solution, not only for the West Coast Main Line, but also for other routes such as the Western Region
Western Region of British Railways
The Western Region was a region of British Railways from 1948. The region ceased to be an operating unit in its own right in the 1980s and was wound up at the end of 1992...
's services to Bristol
Bristol
Bristol is a city, unitary authority area and ceremonial county in South West England, with an estimated population of 433,100 for the unitary authority in 2009, and a surrounding Larger Urban Zone with an estimated 1,070,000 residents in 2007...
, and the Midland Main Line
Midland Main Line
The Midland Main Line is a major railway route in the United Kingdom, part of the British railway system.The present-day line links London St...
to the Midlands
English Midlands
The Midlands, or the English Midlands, is the traditional name for the area comprising central England that broadly corresponds to the early medieval Kingdom of Mercia. It borders Southern England, Northern England, East Anglia and Wales. Its largest city is Birmingham, and it was an important...
and Yorkshire
Yorkshire
Yorkshire is a historic county of northern England and the largest in the United Kingdom. Because of its great size in comparison to other English counties, functions have been increasingly undertaken over time by its subdivisions, which have also been subject to periodic reform...
.
What is often not acknowledged is that the TGV was only a small part of France's total rail network, while, in Japan, the Shinkansen was conceived as a totally new system to replace an increasingly inadequate narrow-gauge service. There was a need to carry upwards of 120 million passengers per year, which meant that its financiers could safely predict a rapid return on investment.
Further uses of APT technology
The initial research into vehicle dynamics was at the cutting edge in the 1960s. The knowledge obtained has passed into mainstream theory, such that it is taken for granted. An early benefit was that freight trains could be sped up, such that hundreds of miles of relief track ('slow lines') could be dispensed with.The APT-P was new throughout and, perhaps, should have remained a 'concept vehicle'. The APT powercar technology was imported almost wholesale, though without the tilt, into the design of the Class 91
British Rail Class 91
The British Rail Class 91 is a class of , electric locomotives ordered as a component of the East Coast Main Line modernisation and electrification programme of the late 1980s. The Class 91s were given the auxiliary name of InterCity 225 to indicate their envisaged top speed of...
locomotives.
While tilting trains had been in development in other countries for some years, and even seen service, so-called 'pendular tilt' had not been particularly satisfactory. The designs of the APT 'powered tilt' carriages were sold to Fiat Ferroviaria
Fiat
FIAT, an acronym for Fabbrica Italiana Automobili Torino , is an Italian automobile manufacturer, engine manufacturer, financial, and industrial group based in Turin in the Italian region of Piedmont. Fiat was founded in 1899 by a group of investors including Giovanni Agnelli...
, which exploited the technology in the design of the second generation of the functionally similar Pendolino
Pendolino
Pendolino is an Italian family of tilting trains used in Italy, Spain, Portugal, Slovenia, Finland, Russian Federation, the Czech Republic, the United Kingdom, Slovakia, Switzerland, China and shortly in Romania and Poland...
trains, coupled with an in-house electronic control system (first generation systems had been in service since 1976). Italian Pendolino systems incorporating original APT technology have since been sold internationally to various rail networks, including the British Class 390 Pendolino
British Rail Class 390
The Class 390 Pendolino is a type of train used in Great Britain. They are electric multiple units using Fiat's tilting train pendolino technology and built by Alstom. Fifty-three 9-car units were originally built for Virgin Trains from 2001 to 2004 for operation on the West Coast Main Line , with...
introduced on the West Coast Main Line
West Coast Main Line
The West Coast Main Line is the busiest mixed-traffic railway route in Britain, being the country's most important rail backbone in terms of population served. Fast, long-distance inter-city passenger services are provided between London, the West Midlands, the North West, North Wales and the...
from late 2003 onwards, culminating in September 2004 with the introduction of a full passenger timetable, with tilting enabled from Manchester
Manchester
Manchester is a city and metropolitan borough in Greater Manchester, England. According to the Office for National Statistics, the 2010 mid-year population estimate for Manchester was 498,800. Manchester lies within one of the UK's largest metropolitan areas, the metropolitan county of Greater...
and Birmingham
Birmingham
Birmingham is a city and metropolitan borough in the West Midlands of England. It is the most populous British city outside the capital London, with a population of 1,036,900 , and lies at the heart of the West Midlands conurbation, the second most populous urban area in the United Kingdom with a...
to London Euston.
Although the APT failed, this was not primarily due to the system, which, given enough time to iron out the inevitable technical problems of brand new technology, could have worked; instead it was due to management failures concerning the introduction of the APT Project. Too much technology, lack of commitment and moved goalposts are also blamed. It is interesting to note that, even 25 years later (on an upgraded infrastructure) the Class 390 Pendolinos can only now match the APT's scheduled timings. The London to Glasgow route by APT (1980/81 timetable) was 4hrs 10min, the same time as the fastest Pendolino
Pendolino
Pendolino is an Italian family of tilting trains used in Italy, Spain, Portugal, Slovenia, Finland, Russian Federation, the Czech Republic, the United Kingdom, Slovakia, Switzerland, China and shortly in Romania and Poland...
timing (December 2008 timetable). Recently (on a one off non-stop run for charity), a Pendolino completed the Glasgow to London journey in 3hrs 55min, whereas the APT completed the opposite London to Glasgow journey in 3hrs 52min in 1984.