London Underground 1996 Stock
Encyclopedia
The London Underground
1996 Stock is a deep tube train used on the Jubilee Line
and one of the newest trains currently running on the network. They were built by Alstom
and began service in 1997. They are similar to the 1995 Stock
used on the Northern Line
, having been built at a similar time by the same manufacturer.
's 1995 stock
. The development programmes for both stocks was run in parallel, with detail design work undertaken by Alstom in the UK at their Birmingham and Rugby facilities, with the first six train sets manufactured in Alstom's Barcelona
factory to the 1996 Stock Jubilee Line design. All type approvals for the design were conducted on these early train sets. The production of the 1995 Stock for the Northern Line subsequently followed from the factory in Barcelona. The balance of the 1996 Stock for the Jubilee Line followed the 1995 Stock Production. Both stocks were freighted to Alstom's facility at Washwood Heath
in Birmingham
for final assembly and equipping, with 1995 and 1996 stock assembled in adjacent production lines.
The 1996 Stock was bought to support the opening of the Jubilee Line Extension
(JLE) from to . However, delays in the JLE's opening meant that 1996 Stock was introduced, completely replacing the existing fleet of 1983 Stock
, between Christmas Eve
1997 and July 1998 - over a year before the JLE was opened. The existing trains (1983 stock) were originally planned to be refurbished with the same exterior and interior as the new stock (1996 stock) even with double doors, but the cost proved prohibitive.
The 1995 and 1996 Stock trains, while similar, have different interiors, seating layouts and cab designs designed by Warwick Design Consultants. Other differences include different traction packages (Alstom ONIX system on 1995 Northern Line stock), Train Management Systems, slight differences with Tripcock geometry and the use of LED body-side lights on the 1995 Northern Line Tube stock while 1996 Tube stock uses filament bulbs
. The most apparent difference between the two stocks is the bogie
. The 1996 Stock utilises an Alstom bogie with a rubber suspension whereas the 1995 Stock has fitted AdTranz
(now owned by Bombardier
) bogies with air suspension
to cope with the arduous track conditions encountered on the underground portions of the Northern Line. The main technical differences occurred because the 1996 Stock was designed as "Cheapest first cost" for LUL, while the 1995 Stock was designed for "Life Cycle Cost" as Alstom had won the contract to act as service provider and maintainer of this stock. Alstom subsequently won the maintenance of the 1996 Stock to be carried out at the newly constructed Stratford
Market depot in East London.
The 1996 Stock is operated with a dead man's handle
at the driver's right hand. When the train is stopped the top of the handle is turned away from the position in which the driver holds it. To depart the driver turns the top of the handle and pushes the red lever forward. The trains were originally designed for automatic train operation
as on the Victoria
and Central Line
s, using a Westinghouse
system, however, due to operational problems with the system and the cost of upgrading the signalling line-side infrastructure, this system will never enter service. A new system based on the Alcatel
SelTrac
as used on the Docklands Light Railway
has been installed across the fleet; this is the first application of this system on an underground mass transit line and is referred to as Transmission-Based Train Control (TBTC). This is a 'moving block' system that will allow trains to run faster and closer together without compromising safety, and is crucial to allow Tube Lines to meet future timetable and passenger loading targets.
The original seat covers were a mauve and grey moquette
. They formed the letter 'J' for Jubilee, as much as the Northern Line's moquette forms the letter 'N'.
In November 2005 the old cars were refurbished and these seat covers were replaced with the new dark blue Tube Lines
moquette. This features multi-coloured and multi-size hollow squares. The new cars were ordered with this moquette. The Piccadilly Line
's 1973 Stock
also has this moquette, and it has also now been introduced on the Northern Line stock. The armrests were purple but have been repainted blue to match the new seat covers. However, the new (mark 2) trains delivered in late 2005 were still carrying the old internal layout as of December 2008.
The 1996 Stock as originally delivered consisted of six car trains, with two three car units coupled together. Each unit consists of a Driving Motor car [DM], Trailer car [T], Uncoupling Non-Driving Motor car [UNDM], with a standard train formation of DM-T-UNDM+UNDM-T-DM. Twelve of the later build trailer cars had de-icing equipment installed and are referred to as De-Icing Trailer cars [DIT].
The trains are numbered with both 'odd' and 'even' ends. The number comprises five digits. The first two digits are the stock type [96]. The third digit refers to the car type: 0 or 1 DM, 2 or 3 T, 4 or 5 UNDM. 7 indicates a DIT. For example, a six car train set would be 96001, 96201, 96401, 96402, 96202, 96002.
In the design, each car is given a letter designation. The even cab end car is A, odd cab end car is B, even UNDM is C, odd UNDM is D, trailer cars are E, DIT is F.
in the Barcelona suburbs. The four new trains were built as six-car trains and then modified at the Stratford Depot maintenance facility to the seven-car configuration.
So from 25 December 2005, the line was closed for completion of the seventh-car conversion, including signalling alterations and software modification to the platform edge doors on the JLE. The original plan was to hard wire two cars together so that the onboard computer would "see" them as one car, but this proved not to be necessary. Since the 1996 Stock had been designed as a six-car train set with the ability to add a seventh car to the trainset if necessary, the platforms were already long enough for seven-car trains throughout the line, and the JLE platform edge doors had been built with space for a seventh car. The line was scheduled to close for five days, but the work by Alstom and Tube Lines
was completed ahead of schedule, enabling the line to re-open two days early. The new carriage is a trailer car in the "odd" unit with design designation "G". An example of a seven-car train set would be 96118, 96318, 96718, 96418, 96419, 96219, 96119. [seventh car in bold]
There were various differences between the new and old cars at the time of introduction:
Many of these are likely to change as the old cars undergo refurbishment. The new trailer cars are numbered 96601 to 96725 (odd numbers only). The door seal on the new cars still reads "1996", because of the national production rules. However they feature the newer Alstom
logo, instead of GEC Alstom.
The refurbishment design was carried out by Warwick Design Consultants who also designed the moquette. They were also responsible for the Northern and Picacdilly Line refurbishment designs including the driver's cabs and controls.
Following the introduction, an upgrade to the passenger information system has been introduced, resulting in next station announcements playing on approach to stations.
The voice announcement system makes use of three voices: one female voice for station announcements (Celia Drummond), another female voice to announce the train's destination, and a male voice for alerts such as, "please keep your personal belongings with you, at all times." Announcements are made when approaching a station and when standing at the platform. Listed below are the announcements that play on a Jubilee Line train traveling from Waterloo
to St. John's Wood:
The regular dot matrix pattern at Green Park is as follows:
In between stops, the announcements will also scroll across the displays.
The disparity between the voices used for each part of the announcements is due to the fact that whilst the original recording has been retained for the "This train terminates at... station" announcement, the station announcements have been modified since the installation of the DVA system. The occasional use of a male announcer for general passenger alerts and information like station closures makes the Jubilee Line the second line on the London Underground to use a male voice in its DVA system, after the Piccadilly line (which lost its male voice upon refurbishment).
1995 stock and 1996 stock have similar bodyshells and were both built by Alstom. However, they use different AC traction control systems. The control system on the 1995 stock is more modern than the 1996 stock, reflecting the fact that the latter's design spec was 'frozen' in 1991.
The 1996 stock uses three-phase induction motors fed from a single-source inverter using a GTO (gate-turn-off) thyristor
, derived from those on Class 465 Networker
trains. The 1995 stock, for comparison, uses Alstom's "Onix" three-phase Insulated Gate Bipolar Transistor
drive.
Earlier London Underground stock, like most electric trains until the 1990s, used DC
motors. These are now regarded as inefficient, partly because they are traditionally controlled by resistors, and partly because a 3-phase AC
induction motor can provide higher specific power and volumetric power density. The brushes and commutator of a DC motor are a wear item and require regular maintenance, whilst an induction machine has neither.
However, in an AC motor supplied by a fixed-frequency supply, maximum torque
can only be achieved when the resistance of the rotor windings equals the reactance
. AC motors in an industrial setting tend to be operated at approximately constant speed and therefore large banks of resistors can be used on start-up to raise resistance and maintain torque, if a wound-rotor machine is employed. This would not be efficient in a small motor designed for stop/start operation.
As a result, it was only the invention of electronic control systems from the 1980s onwards that made AC traction viable for trains. The motor can be supplied using an inverter
, and by varying the inverter's output frequency it is possible to keep the frequency of the currents flowing in the rotor windings constant, and hence the reactance. (note the reactance depends on frequency whereas the resistance is fixed)
The GTO thyristor used on 1996 stock achieves this by 'chopping' the supply voltage in order to drive a sinusoidal current in the motor windings (PWM), creating the characteristic audible whine associated with the stock and with the Class 465 Networker
trains that share its traction drive system. The noise timbre
changes as the pulse length changes. The noise is produced by the switching frequency current ripple and resulting torque pulsation experienced by the rotor of the induction machine.
More modern AC traction, such as the 1995 stock, uses the IGBT (which is essentially a combination of the MOSFET
and the BJT
), which can operate at much higher switching frequencies than the GTO
. The 'whine' effect is far less noticeable due to the higher switching frequency of IGBT drives.
London Underground
The London Underground is a rapid transit system serving a large part of Greater London and some parts of Buckinghamshire, Hertfordshire and Essex in England...
1996 Stock is a deep tube train used on the Jubilee Line
Jubilee Line
The Jubilee line is a line on the London Underground , in the United Kingdom. It was built in two major sections—initially to Charing Cross, in central London, and later extended, in 1999, to Stratford, in east London. The later stations are larger and have special safety features, both aspects...
and one of the newest trains currently running on the network. They were built by Alstom
Alstom
Alstom is a large multinational conglomerate which holds interests in the power generation and transport markets. According to the company website, in the years 2010-2011 Alstom had annual sales of over €20.9 billion, and employed more than 85,000 people in 70 countries. Alstom's headquarters are...
and began service in 1997. They are similar to the 1995 Stock
London Underground 1995 Stock
The London Underground's 1995 stock is used in daily service on the Northern Line. There are 106 six car trains in operation; they entered service between 12 June 1998 and 10 April 2001....
used on the Northern Line
Northern Line
The Northern line is a London Underground line. It is coloured black on the Tube map.For most of its length it is a deep-level tube line. The line carries 206,734,000 passengers per year. This is the highest number of any line on the London Underground system, but the Northern line is unique in...
, having been built at a similar time by the same manufacturer.
Overview
There is a degree of confusion with regard to the manufacture and delivery of the Jubilee Line's 1996 stock and the Northern LineNorthern Line
The Northern line is a London Underground line. It is coloured black on the Tube map.For most of its length it is a deep-level tube line. The line carries 206,734,000 passengers per year. This is the highest number of any line on the London Underground system, but the Northern line is unique in...
's 1995 stock
London Underground 1995 Stock
The London Underground's 1995 stock is used in daily service on the Northern Line. There are 106 six car trains in operation; they entered service between 12 June 1998 and 10 April 2001....
. The development programmes for both stocks was run in parallel, with detail design work undertaken by Alstom in the UK at their Birmingham and Rugby facilities, with the first six train sets manufactured in Alstom's Barcelona
Barcelona
Barcelona is the second largest city in Spain after Madrid, and the capital of Catalonia, with a population of 1,621,537 within its administrative limits on a land area of...
factory to the 1996 Stock Jubilee Line design. All type approvals for the design were conducted on these early train sets. The production of the 1995 Stock for the Northern Line subsequently followed from the factory in Barcelona. The balance of the 1996 Stock for the Jubilee Line followed the 1995 Stock Production. Both stocks were freighted to Alstom's facility at Washwood Heath
Washwood Heath
Washwood Heath is a ward in Birmingham, within the formal district of Hodge Hill, roughly two miles north-east of Birmingham city centre, England...
in 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...
for final assembly and equipping, with 1995 and 1996 stock assembled in adjacent production lines.
The 1996 Stock was bought to support the opening of the Jubilee Line Extension
Jubilee Line Extension
The Jubilee Line Extension is the extension of the London Underground Jubilee line from to through south and east London. An eastward extension of the Jubilee line was first proposed in the 1970s and a modified route was constructed during the 1990s...
(JLE) from to . However, delays in the JLE's opening meant that 1996 Stock was introduced, completely replacing the existing fleet of 1983 Stock
London Underground 1983 Stock
The London Underground 1983 Stock was a class of electric multiple unit designed for the Jubilee Line.The 1983 Tube Stock could be considered the last train to be designed by London Underground; it was the last conventional Tube train in the long line of evolving design since the 1938 Tube...
, between Christmas Eve
Christmas Eve
Christmas Eve refers to the evening or entire day preceding Christmas Day, a widely celebrated festival commemorating the birth of Jesus of Nazareth that takes place on December 25...
1997 and July 1998 - over a year before the JLE was opened. The existing trains (1983 stock) were originally planned to be refurbished with the same exterior and interior as the new stock (1996 stock) even with double doors, but the cost proved prohibitive.
The 1995 and 1996 Stock trains, while similar, have different interiors, seating layouts and cab designs designed by Warwick Design Consultants. Other differences include different traction packages (Alstom ONIX system on 1995 Northern Line stock), Train Management Systems, slight differences with Tripcock geometry and the use of LED body-side lights on the 1995 Northern Line Tube stock while 1996 Tube stock uses filament bulbs
Incandescent light bulb
The incandescent light bulb, incandescent lamp or incandescent light globe makes light by heating a metal filament wire to a high temperature until it glows. The hot filament is protected from air by a glass bulb that is filled with inert gas or evacuated. In a halogen lamp, a chemical process...
. The most apparent difference between the two stocks is the bogie
Bogie
A bogie is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a railway carriage/car or locomotive, or sprung as in the suspension of a caterpillar...
. The 1996 Stock utilises an Alstom bogie with a rubber suspension whereas the 1995 Stock has fitted AdTranz
Adtranz
ABB Daimler-Benz Transportation , commonly known under its brand Adtranz, was a multi-national rail transport equipment manufacturer with facilities concentrated in Europe and the USA....
(now owned by Bombardier
Bombardier Transportation
Bombardier Transportation is the rail equipment division of the Canadian firm, Bombardier Inc. Bombardier Transportation is one of the world's largest companies in the rail-equipment manufacturing and servicing industry. Its headquarters are in Berlin, Germany....
) bogies with air suspension
Air suspension
Air suspension is a type of vehicle suspension powered by an engine driven or electric air pump or compressor. This pump pressurizes the air, using compressed air as a spring. Air suspension replaces conventional steel springs. If the engine is left off for an extended period, the car will settle...
to cope with the arduous track conditions encountered on the underground portions of the Northern Line. The main technical differences occurred because the 1996 Stock was designed as "Cheapest first cost" for LUL, while the 1995 Stock was designed for "Life Cycle Cost" as Alstom had won the contract to act as service provider and maintainer of this stock. Alstom subsequently won the maintenance of the 1996 Stock to be carried out at the newly constructed Stratford
Stratford, London
Stratford is a place in the London Borough of Newham, England. It is located east northeast of Charing Cross and is one of the major centres identified in the London Plan. It was historically an agrarian settlement in the ancient parish of West Ham, which transformed into an industrial suburb...
Market depot in East London.
The 1996 Stock is operated with a dead man's handle
Dead Man's Handle
Dead Man's Handle is the title of a 1985 action-adventure/spy novel written by Peter O'Donnell. It was the eleventh and final full-length novel chronicling the adventures of O'Donnell's comic strip creation, Modesty Blaise...
at the driver's right hand. When the train is stopped the top of the handle is turned away from the position in which the driver holds it. To depart the driver turns the top of the handle and pushes the red lever forward. The trains were originally designed for automatic train operation
Automatic train operation
Automatic train operation ensures partial or complete automatic train piloting and driverless functions.Most systems elect to maintain a driver to mitigate risks associated with failures or emergencies....
as on the Victoria
Victoria Line
The Victoria line is a deep-level London Underground line running from the south to the north-east of London. It is coloured light blue on the Tube map...
and Central Line
Central Line
The Central line is a London Underground line, coloured red on the tube map. It is a deep-level "tube" line, running east-west across London, and, at , has the greatest total length of track of any line on the Underground. Of the 49 stations served, 20 are below ground...
s, using a Westinghouse
Westinghouse
Westinghouse may refer to:In current companies:*Westinghouse Licensing, the brand management division of CBS Corporation, and its licensees:**Westinghouse Electric Company LLC, providing nuclear power related services....
system, however, due to operational problems with the system and the cost of upgrading the signalling line-side infrastructure, this system will never enter service. A new system based on the Alcatel
Alcatel
Alcatel Mobile Phones is a brand of mobile handsets. It was established in 2004 as a joint venture between Alcatel-Lucent of France and TCL Communication of China....
SelTrac
SelTrac
SELTrac is a digital signalling technology used to control the movements of rail vehicles originally developed by Standard Elektrik Lorenz . It was originally developed for the Krauss-Maffei Transurban automated guideway transit system developed in the 1970s, and moved to the ICTS vehicle when the...
as used on the Docklands Light Railway
Docklands Light Railway
The Docklands Light Railway is an automated light metro or light rail system opened on 31 August 1987 to serve the redeveloped Docklands area of London...
has been installed across the fleet; this is the first application of this system on an underground mass transit line and is referred to as Transmission-Based Train Control (TBTC). This is a 'moving block' system that will allow trains to run faster and closer together without compromising safety, and is crucial to allow Tube Lines to meet future timetable and passenger loading targets.
The original seat covers were a mauve and grey moquette
Moquette
Moquette is type of fabric with a thick, dense pile. It is a particularly versatile and hard-wearing material, predominantly wool with a small percentage of polyester. Moquette is renowned for its attractive, hard-wearing, durable, and fire-resistant qualities, hence it is commonly used for...
. They formed the letter 'J' for Jubilee, as much as the Northern Line's moquette forms the letter 'N'.
In November 2005 the old cars were refurbished and these seat covers were replaced with the new dark blue Tube Lines
Tube Lines
Tube Lines Limited, initially known as 'Infraco JNP', has been a wholly owned subsidiary of Transport for London since May 2010. Tube Lines is an asset-management company responsible for the maintenance, renewal and upgrade of the infrastructure, including track, trains, signals, civil work and...
moquette. This features multi-coloured and multi-size hollow squares. The new cars were ordered with this moquette. The Piccadilly Line
Piccadilly Line
The Piccadilly line is a line of the London Underground, coloured dark blue on the Tube map. It is the fifth busiest line on the Underground network judged by the number of passengers transported per year. It is mainly a deep-level line, running from the north to the west of London via Zone 1, with...
's 1973 Stock
London Underground 1973 Stock
The 1973 Tube Stock operates on the Piccadilly line of the London Underground and was introduced in 1975 for the opening of the extension to Hatton Cross .-Construction:...
also has this moquette, and it has also now been introduced on the Northern Line stock. The armrests were purple but have been repainted blue to match the new seat covers. However, the new (mark 2) trains delivered in late 2005 were still carrying the old internal layout as of December 2008.
The 1996 Stock as originally delivered consisted of six car trains, with two three car units coupled together. Each unit consists of a Driving Motor car [DM], Trailer car [T], Uncoupling Non-Driving Motor car [UNDM], with a standard train formation of DM-T-UNDM+UNDM-T-DM. Twelve of the later build trailer cars had de-icing equipment installed and are referred to as De-Icing Trailer cars [DIT].
The trains are numbered with both 'odd' and 'even' ends. The number comprises five digits. The first two digits are the stock type [96]. The third digit refers to the car type: 0 or 1 DM, 2 or 3 T, 4 or 5 UNDM. 7 indicates a DIT. For example, a six car train set would be 96001, 96201, 96401, 96402, 96202, 96002.
In the design, each car is given a letter designation. The even cab end car is A, odd cab end car is B, even UNDM is C, odd UNDM is D, trailer cars are E, DIT is F.
Addition of seventh car
During early 2005, London Underground announced that it would be adding a seventh car to the trains of the existing Jubilee Line fleet, and also adding four new complete trains. With the original factory having been closed on the Barcelona beach front, the four new train sets and sixty three new trailer cars were manufactured in Alstom's new factory at Santa Perpètua de MogodaSanta Perpètua de Mogoda
Santa Perpètua de Mogoda is a municipality in the comarca of Vallès Occidental inCatalonia.-References:* Panareda Clopés, Josep Maria; Rios Calvet, Jaume; Rabella Vives, Josep Maria . Guia de Catalunya, Barcelona:Caixa de Catalunya. ISBN 84-87135-02-1 .-External links :*...
in the Barcelona suburbs. The four new trains were built as six-car trains and then modified at the Stratford Depot maintenance facility to the seven-car configuration.
So from 25 December 2005, the line was closed for completion of the seventh-car conversion, including signalling alterations and software modification to the platform edge doors on the JLE. The original plan was to hard wire two cars together so that the onboard computer would "see" them as one car, but this proved not to be necessary. Since the 1996 Stock had been designed as a six-car train set with the ability to add a seventh car to the trainset if necessary, the platforms were already long enough for seven-car trains throughout the line, and the JLE platform edge doors had been built with space for a seventh car. The line was scheduled to close for five days, but the work by Alstom and Tube Lines
Tube Lines
Tube Lines Limited, initially known as 'Infraco JNP', has been a wholly owned subsidiary of Transport for London since May 2010. Tube Lines is an asset-management company responsible for the maintenance, renewal and upgrade of the infrastructure, including track, trains, signals, civil work and...
was completed ahead of schedule, enabling the line to re-open two days early. The new carriage is a trailer car in the "odd" unit with design designation "G". An example of a seven-car train set would be 96118, 96318, 96718, 96418, 96419, 96219, 96119. [seventh car in bold]
There were various differences between the new and old cars at the time of introduction:
- Amber passenger information displays (PIDs) instead of red
- Black vestibule floor instead of grey
- Yellow strip on door seal
- Better fitted seat covers
- The ridged vestibule floor extends the width of the car
Many of these are likely to change as the old cars undergo refurbishment. The new trailer cars are numbered 96601 to 96725 (odd numbers only). The door seal on the new cars still reads "1996", because of the national production rules. However they feature the newer Alstom
Alstom
Alstom is a large multinational conglomerate which holds interests in the power generation and transport markets. According to the company website, in the years 2010-2011 Alstom had annual sales of over €20.9 billion, and employed more than 85,000 people in 70 countries. Alstom's headquarters are...
logo, instead of GEC Alstom.
The refurbishment design was carried out by Warwick Design Consultants who also designed the moquette. They were also responsible for the Northern and Picacdilly Line refurbishment designs including the driver's cabs and controls.
Following the introduction, an upgrade to the passenger information system has been introduced, resulting in next station announcements playing on approach to stations.
Digital voice announcements
The Jubilee Line stock is fitted with a digital voice announcement system and dot-matrix displays to provide passenger information.The voice announcement system makes use of three voices: one female voice for station announcements (Celia Drummond), another female voice to announce the train's destination, and a male voice for alerts such as, "please keep your personal belongings with you, at all times." Announcements are made when approaching a station and when standing at the platform. Listed below are the announcements that play on a Jubilee Line train traveling from Waterloo
Waterloo tube station
Waterloo tube station is a London Underground station located at Waterloo station. It is the second busiest station on the network and is served by the Bakerloo, Jubilee, Northern and the Waterloo & City lines...
to St. John's Wood:
Approaching Waterloo: "The next station is Waterloo. Change for the Bakerloo, Northern and Waterloo & City Lines, and National Rail services."
Upon arrival at Waterloo: "This station is . Change here for the BakerlooBakerloo LineThe Bakerloo line is a line of the London Underground, coloured brown on the Tube map. It runs partly on the surface and partly at deep level, from Elephant and Castle in the south-east to Harrow & Wealdstone in the north-west of London. The line serves 25 stations, of which 15 are underground...
, NorthernNorthern LineThe Northern line is a London Underground line. It is coloured black on the Tube map.For most of its length it is a deep-level tube line. The line carries 206,734,000 passengers per year. This is the highest number of any line on the London Underground system, but the Northern line is unique in...
and Waterloo & City LineWaterloo & City LineThe Waterloo & City line is a short underground railway line in London, which was formally opened on 11 July 1898. It has only two stations, Waterloo and Bank...
s, and National RailNational RailNational Rail is a title used by the Association of Train Operating Companies as a generic term to define the passenger rail services operated in Great Britain...
services." "This train terminates at StanmoreStanmore tube stationStanmore tube station is a London Underground station at Stanmore. It is the northern terminus of the Jubilee Line; the previous station is Canons Park. It is in Travelcard Zone 5...
."
Approaching Westminster: "The next station is Westminster. Change for the Circle and District Lines. Exit for Westminster Abbey and Houses of Parliament."
Upon arrival at Westminster: "This station is . Change here for Circle and District LineDistrict LineThe District line is a line of the London Underground, coloured green on the Tube map. It is a "sub-surface" line, running through the central area in shallow cut-and-cover tunnels. It is the busiest of the sub-surface lines. Out of the 60 stations served, 25 are underground...
s. Exit for Westminster AbbeyWestminster AbbeyThe Collegiate Church of St Peter at Westminster, popularly known as Westminster Abbey, is a large, mainly Gothic church, in the City of Westminster, London, United Kingdom, located just to the west of the Palace of Westminster. It is the traditional place of coronation and burial site for English,...
and Houses of ParliamentPalace of WestminsterThe Palace of Westminster, also known as the Houses of Parliament or Westminster Palace, is the meeting place of the two houses of the Parliament of the United Kingdom—the House of Lords and the House of Commons...
." "This train terminates at .
Approaching Green Park: "The next station is Green Park. Change for the Piccadilly and Victoria Lines. Exit for Buckingham Palace."
Upon arrival at Green Park: "This station is . Change here for the PiccadillyPiccadilly LineThe Piccadilly line is a line of the London Underground, coloured dark blue on the Tube map. It is the fifth busiest line on the Underground network judged by the number of passengers transported per year. It is mainly a deep-level line, running from the north to the west of London via Zone 1, with...
and Victoria LineVictoria LineThe Victoria line is a deep-level London Underground line running from the south to the north-east of London. It is coloured light blue on the Tube map...
s. Exit here for Buckingham PalaceBuckingham PalaceBuckingham Palace, in London, is the principal residence and office of the British monarch. Located in the City of Westminster, the palace is a setting for state occasions and royal hospitality...
." "This train terminates at ."
Approaching Bond Street: "The next station is Bond Street. Change for the Central Line."
Upon arrival at Bond Street: "This station is . Change here for the Central LineCentral LineThe Central line is a London Underground line, coloured red on the tube map. It is a deep-level "tube" line, running east-west across London, and, at , has the greatest total length of track of any line on the Underground. Of the 49 stations served, 20 are below ground...
." "This train terminates at ."
Approaching Baker Street: "The next station is Baker Street. Change for the Bakerloo, Hammersmith & City, Circle and Metropolitan Lines."
Upon arrival at Baker Street: "This station is . Change here for the BakerlooBakerloo LineThe Bakerloo line is a line of the London Underground, coloured brown on the Tube map. It runs partly on the surface and partly at deep level, from Elephant and Castle in the south-east to Harrow & Wealdstone in the north-west of London. The line serves 25 stations, of which 15 are underground...
, Hammersmith & CityHammersmith & City LineThe Hammersmith & City line is a subsurface London Underground line. It connects Hammersmith in the west with Barking in the east, running through the northern part of central London. It is coloured salmon pink on the Tube map...
, Circle and Metropolitan LineMetropolitan LineThe Metropolitan line is part of the London Underground. It is coloured in Transport for London's Corporate Magenta on the Tube map and in other branding. It was the first underground railway in the world, opening as the Metropolitan Railway on 10 January 1863...
s." "This train terminates at Stanmore."
Approaching St. John's Wood: "The next station is St. John's Wood."
Upon arrival at St. John's Wood: "This station is St. John's Wood." "This train terminates at StanmoreStanmore tube stationStanmore tube station is a London Underground station at Stanmore. It is the northern terminus of the Jubilee Line; the previous station is Canons Park. It is in Travelcard Zone 5...
."
The regular dot matrix pattern at Green Park is as follows:
"Green Park" - "Destination : Stanmore"
In between stops, the announcements will also scroll across the displays.
The disparity between the voices used for each part of the announcements is due to the fact that whilst the original recording has been retained for the "This train terminates at... station" announcement, the station announcements have been modified since the installation of the DVA system. The occasional use of a male announcer for general passenger alerts and information like station closures makes the Jubilee Line the second line on the London Underground to use a male voice in its DVA system, after the Piccadilly line (which lost its male voice upon refurbishment).
Traction control
The 1996 stock uses three-phase induction motors fed from a single-source inverter using a GTO (gate-turn-off) thyristor
Thyristor
A thyristor is a solid-state semiconductor device with four layers of alternating N and P-type material. They act as bistable switches, conducting when their gate receives a current trigger, and continue to conduct while they are forward biased .Some sources define silicon controlled rectifiers and...
, derived from those on Class 465 Networker
British Rail Class 465
The British Rail Class 465 Networker electric multiple units were built by GEC Alsthom and BREL between 1991 and 1993, and by ABB Rail between 1993 and 1994. They were brought into service from 1991 onwards. They are mostly used on suburban routes serving the South East of England, now operated by...
trains. The 1995 stock, for comparison, uses Alstom's "Onix" three-phase Insulated Gate Bipolar Transistor
Insulated gate bipolar transistor
The insulated gate bipolar transistor or IGBT is a three-terminal power semiconductor device primarily used as an electronic switch and in newer devices is noted for combining high efficiency and fast switching...
drive.
Earlier London Underground stock, like most electric trains until the 1990s, used DC
Direct current
Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...
motors. These are now regarded as inefficient, partly because they are traditionally controlled by resistors, and partly because a 3-phase AC
Alternating current
In alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction....
induction motor can provide higher specific power and volumetric power density. The brushes and commutator of a DC motor are a wear item and require regular maintenance, whilst an induction machine has neither.
However, in an AC motor supplied by a fixed-frequency supply, maximum torque
Torque
Torque, moment or moment of force , is the tendency of a force to rotate an object about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist....
can only be achieved when the resistance of the rotor windings equals the reactance
Reactance
Reactance is the opposition of a circuit element to a change of electric current or voltage, due to that element's capacitance or inductance. A built-up electric field resists the change of voltage on the element, while a magnetic field resists the change of current...
. AC motors in an industrial setting tend to be operated at approximately constant speed and therefore large banks of resistors can be used on start-up to raise resistance and maintain torque, if a wound-rotor machine is employed. This would not be efficient in a small motor designed for stop/start operation.
As a result, it was only the invention of electronic control systems from the 1980s onwards that made AC traction viable for trains. The motor can be supplied using an inverter
Inverter
Inverter may refer to* Inverter , a device that converts direct current to alternating current** Inverter , an air conditioner that can continuously regulate its output by altering the compressor speed in response to cooling demand** Uninterruptible power supply, which often are based on an...
, and by varying the inverter's output frequency it is possible to keep the frequency of the currents flowing in the rotor windings constant, and hence the reactance. (note the reactance depends on frequency whereas the resistance is fixed)
The GTO thyristor used on 1996 stock achieves this by 'chopping' the supply voltage in order to drive a sinusoidal current in the motor windings (PWM), creating the characteristic audible whine associated with the stock and with the Class 465 Networker
British Rail Class 465
The British Rail Class 465 Networker electric multiple units were built by GEC Alsthom and BREL between 1991 and 1993, and by ABB Rail between 1993 and 1994. They were brought into service from 1991 onwards. They are mostly used on suburban routes serving the South East of England, now operated by...
trains that share its traction drive system. The noise timbre
Timbre
In music, timbre is the quality of a musical note or sound or tone that distinguishes different types of sound production, such as voices and musical instruments, such as string instruments, wind instruments, and percussion instruments. The physical characteristics of sound that determine the...
changes as the pulse length changes. The noise is produced by the switching frequency current ripple and resulting torque pulsation experienced by the rotor of the induction machine.
More modern AC traction, such as the 1995 stock, uses the IGBT (which is essentially a combination of the MOSFET
MOSFET
The metal–oxide–semiconductor field-effect transistor is a transistor used for amplifying or switching electronic signals. The basic principle of this kind of transistor was first patented by Julius Edgar Lilienfeld in 1925...
and the BJT
Bipolar junction transistor
|- align = "center"| || PNP|- align = "center"| || NPNA bipolar transistor is a three-terminal electronic device constructed of doped semiconductor material and may be used in amplifying or switching applications. Bipolar transistors are so named because their operation involves both electrons...
), which can operate at much higher switching frequencies than the GTO
Gate turn-off thyristor
A gate turn-off thyristor is a special type of thyristor, a high-power semiconductor device. GTOs, as opposed to normal thyristors, are fully controllable switches which can be turned on and off by their third lead, the GATE lead.-Device description:...
. The 'whine' effect is far less noticeable due to the higher switching frequency of IGBT drives.