British Rail Class 373

The British Rail Class 373 or TGV-TMST train is an electric multiple unit that operates Eurostar's high-speed rail service between Britain, France and Belgium via the Channel Tunnel. Part of the TGV family, it has a smaller cross-section to fit within the constrictive British loading gauge, was originally able to operate on the UK third rail network, and has extensive fireproofing in case of fire in the tunnel. This is both the longest—394 m—and fastest train in regular UK passenger service.

Known as the TransManche Super Train (Cross-channel Super Train) during development up until start of service in 1993, the train is designated Class 373 under the British TOPS classification system and as series 373000 TGV in France. It was built by GEC-Alsthom (now Alstom) at its sites in La Rochelle (France), Belfort (France) and Washwood Heath (UK) and by Brugeoise et Nivelles (BN, now part of Bombardier) in Brugge.

Development and construction
Two types were constructed:
 * Thirty-one "Three Capitals" sets consisting of two power cars and 18 carriages, including two with powered bogies. These trains are 394 metres long and can carry 750 passengers; 206 in first class, 544 in standard class.
 * Seven shorter "North of London" trains which have 14 carriages and are 320 metres in length. These still include two carriages with powered bogies, resulting in a higher power-to-weight-ratio. These sets have a capacity of 558 seats;  114 in first class, 444 in standard class).  These were designed to operate the proposed Regional Eurostar services.

Thirty-eight full sets were ordered by the railway companies involved: 16 by SNCF; four by NMBS/SNCB; and 18 by British Rail, of which seven were North of London sets. Upon privatisation of British Rail by the UK Government, the sets were bought by London and Continental Railways, which named the subsidiary Eurostar (U.K.) Ltd., now managed by a consortium made up of the National Express Group (40%), SNCF (35%), SNCB (15%) and British Airways (10%).

The first Eurostar set was built at Belfort in 1992. Identified as "PS1" (Pre-Series 1), it was formed of just seven coaches and two power cars, and was delivered for test running in January 1993. Its first powered runs were between Strasbourg and Mulhouse, and it was transferred to the UK for third-rail DC tests in June 1993. A second, full-length, pre-series train PS2 was completed in May 1993.

One extra power car, numbered 3999, was built as a spare for use in the event of another power car being damaged or destroyed. This was required for a couple of years, when 3999 was renumbered and replaced another power car whilst it underwent rebuilding at Le Landy. It is usually held at Temple Mills depot in London.

Third rail test train
To test the third rail shoes planned for the Class 373 units on the Southern Region lines in Great Britain, an eight vehicle locomotive hauled train was formed and used in early 1994. This consisted of a Class 73 locomotive, a converted Class 33 locomotive acting as a Driving Brake Van (classified as NZ under TOPS), and six carriages from three Class 438 (4TC) multiple unit sets, 8007, 8023 and 8028.
 * Formation
 * Class 73 - 73205
 * Class 33 (NZ) - 33115
 * Class 438 DTSO - 76281
 * Class 438 TFK - 70850
 * Class 438 TFK - 70871
 * Class 438 TFK - 70866
 * Class 438 TBSK - 70818
 * Class 438 DTSO - 76282

Mid-life update
The 27 sets operating on Eurostar's routes were refurbished in 2004/2005 with a new interior, designed by Philippe Starck. The grey-yellow look (in Standard class) and the grey-red look (in First class) have been replaced with a more grey-brown look in Standard, and a grey-burnt orange in First class.

In 2008, Eurostar announced that it was beginning the process to institute a mid-life update of its Class 373 trains. This process will take in the 28 units making up the Eurostar fleet, but will not include those units used exclusively in France by SNCF. As a part of the update process, the Italian company Pininfarina has been contracted to redesign the interiors; the first refurbished Eurostar is not due in service until 2012. The refurbishment could also include an engine maintenance and a new livery. Eurostar plans for the entire process to be complete by 2014, allowing the fleet to remain in service beyond 2020.

Maintenance
Maintenance of the fleet is carried out at depots close to the three capital cities. With the opening of High Speed 1 on 14 November 2007, the depot for London was changed from North Pole International depot adjacent to the Great Western Main Line in west London, to Temple Mills depot near Stratford International in east London. This is where the unused spare power car is stored. In France the trains are maintained at Le Landy depot in northern Paris, and in Belgium at Brussels Forest/Vorst depot.

Eurostar


The bulk of the fleet's operations are on Eurostar's core routes from London St Pancras to Paris Gare du Nord and Brussels-South railway station (Bruxelles-Midi; Brussel-Zuid). A daily return service operates between London and Disneyland Paris. At particular times of the year, sets equipped for operation on French lignes classiques (classic lines) operate to Avignon Centre railway station (summer only) or on "ski-train" services to Bourg-Saint-Maurice (winter time only).

The trains can operate at up to 300 km/h on high-speed lines and 160 km/h in the Channel Tunnel; there is an automatic application of the brakes if the speed exceeds 315 km/h, or 170 km/h when the pantograph is in the tunnel setting. Speeds within the Channel Tunnel are dictated by air resistance, energy (heat) dissipation and the need to fit in with other train services operating at lower speeds.

SNCF


Three of the Three Capitals sets owned by SNCF are in French domestic use on the TGV network, mainly operating services between Paris and Lille and currently carrying a variation on the standard silver and blue TGV livery. These sets were originally built to the same specification as the rest of the fleet, which saw them initially used on international services as well as French domestic routes. Later, the third rail pick up shoes and yellow front warning panels were removed. In 2007, SNCF enhanced their fleet by leasing six and a half of the seven redundant North of London sets, with one half-set remaining with Eurostar. The North of London sets were originally intended to provide direct Regional Eurostar services from Continental Europe to and from UK cities north of London, using the West Coast Main Line and the East Coast Main Line. These never came to fruition because of long proposed journey times, and the proliferation of budget airlines offering lower fares. There were also issues with the relatively crude design of British Rail overhead lines and the logistics of getting the trains across London. SNCF's lease of the sets is scheduled to last until 2011, with an option for a further two years.

GNER


Five of the North of London sets were leased to GNER in 2000 to provide additional capacity on its routes from London King's Cross. The units were utilised on its White Rose titled services to York, and later to Leeds. These were stripped of their Eurostar markings, two sporting a mostly-white livery, with three sets in the pool receiving full-length GNER-style deep-navy vinyl wraps. On rare occasions sets were formed of both a GNER and an unbranded Eurostar halfset. The lease ended in December 2005, after which they were returned to Eurostar. Due to limitations in the power supply on the East Coast Main Line the units were barred from operating at times of peak electrical demand. The reason the trains were restricted to run between King's Cross and York and later to Leeds due to the fact the sets compromised of 14 coaches and the three stations (including intermediate stations served by the units between the sectors) had platforms long enough to handle the extra length and due to the 110 mph speed restriction for the units.

Fleet details
Each power car has a four-digit number starting with "3" (3xxx). This designates the train as a Mark 3 TGV (Mark 1 being SNCF TGV Sud-Est; Mark 2 being SNCF TGV Atlantique). The second digit denotes the country of ownership:
 * 30xx UK
 * 31xx Belgium
 * 32xx France
 * 33xx Regional Eurostar

Each half-set is numbered separately:

Each full trainset is formed of two power cars and eighteen coaches, ordered as shown in the table below:

Power
When built, all train sets were tri-voltage, being able to operate on 25 kV, 50 Hz AC (LGVs, Eurotunnel, High Speed 1, UK overhead electrified lines) and 3 kV DC (Belgian classic lines) using pantographs and 750 V DC (UK third rail network) using third-rail pickup shoes. The shoes were retracted when operating from overhead power and prototypes were used for testing. After the opening of High Speed 1, overhead electricity is available throughout the core network between London and Paris / Brussels and the third rail shoes became redundant and were removed. The railway links to the new London-based depot facilities at Temple Mills and to the East Coast Main Line and West-Coast Main Line are 25 kV overhead. Five of the SNCF-owned sets are quadri-voltage, being able to operate from 1,500 V DC (French lignes classiques) in the south of France; these sets are used for London–Avignon and ski services.

British-designed asynchronous traction motors are used. There are four powered axles in each power car and one additional bogie in the adjacent passenger carriage. This layout was also used on the original SNCF TGV Sud-Est (PSE) sets. The six powered bogies therefore contain a total of twelve powered axles to haul the rake of eighteen carriages. Drawing up to 12 MW of power, the train has the lowest power-to-weight ratio of any train in the TGV family—a SNCF TGV Réseau set has eight powered axles but is only required to haul eight passenger carriages.

The train design is able to cope with five different standards of overhead catenary: domestic catenary in each of Belgium, France and the United Kingdom; fixed-height catenary for the LGV lines and the taller catenary used within the Channel Tunnel. The Eurotunnel catenary is much higher as the tunnel is designed to accommodate the double-deck car-carrying trains and roll-on roll-off heavy goods vehicle trains. The train driver is required to lower and then raise the pantograph during the change from each catenary system.

Signalling systems
The trains must be fitted with the signalling systems used in all regions of operation, leading to a cluttered control desk in the driver's cab. These include
 * Automatic Warning System, the British signalling system (induction based), used in the Ashford International area
 * Train Protection & Warning System, the warning system which supplements AWS, used in the Ashford International area
 * Transmission Voie-Machine (TVM), used on lignes à grande vitesse, on the Eurotunnel tracks, and on High Speed 1.
 * Contrôle de vitesse par balises, the system used between Paris Gare du Nord and the LGV Nord, on other French lignes classiques and HS1-connected throat around St. Pancras. The system is electro-mechanical with fixed radio beacons.
 * TBL, the Belgian signalling system (electro-mechanical), used between Brussels-South and HSL 1

At high speed, the driver is considered to be unable to see line side signals reliably and to be able to respond accordingly. With the TVM signalling used on the high-speed lines, the target speed for the end of the current block is displayed, along with a flashing indication for the next block if it is a different speed. In addition, auxiliary signalling information is transmitted, including the location of neutral sections in the overhead supply and pantograph adjustment zones. This extra information is displayed in cab as well as by the line side. The operation of a Eurostar's circuit breakers over the neutral sections is handled automatically on the TVM-signalled lines only, but the pantograph adjustments must always be performed by the driver.

Bogies and couplings
The trains were designed with Channel Tunnel safety in mind, and consist of two independent "half-sets", each with its own power car. Most of the trailers rest on Jacobs bogies which are shared between adjacent carriages, supporting both of them. However, the power cars at each end of the train and the two central trailers (coaches 9 and 10 in a full-length set) rest partially or fully on their own bogies. Across the non-shared bogies, the set is coupled together using a Scharfenberg coupler, providing three points for easy separation in the event of an emergency in the Channel Tunnel. The electrical supply cables between a power-car and the first carriage are designed to break apart during an emergency separation of the train. In the event of a serious fire on board while travelling through the Tunnel, the passengers would be transferred into the undamaged half of the train, which would then be uncoupled from the damaged half and driven out of the tunnel to safety. If the undamaged part is the rear half of the train, this would be driven by the Chef du Train who is a fully authorised driver and occupies the rear driving cab while the train travels through the tunnel for this purpose. In fact, due to limitations on driving hours, once the train has reached its destination, the driver and Chef du Train exchange roles for the return journey.

The articulated design is advantageous during a derailment as the passenger carriages will tend to stay aligned in the event of a derailment. On non-articulated trains, by contrast, couplings may split and the carriages may jackknife. A disadvantage of articulation is that it is difficult to remove individual carriages for maintenance. While the power cars can be separated from trains via standard uncoupling procedures, specialised depot equipment is needed to split carriages by lifting the entire train at once. Once uncoupled, one of the carriage ends is left without a bogie at the split, so a bogie frame is required to support it.

Braking systems
The train has three braking systems: The combined effect of the three braking systems can bring a train travelling at 300 km/h to a complete standstill in 65 seconds, during which time the train covers about 3.5 kilometres.
 * The twelve motors can provide rheostatic braking.
 * All non-powered axles have four disc brakes on them.
 * Both power cars and the powered axles on the adjacent (powered) trailer have wheel brakes capable of operating directly on the wheels.

Miscellaneous
In order to combat the hypnotic effect of driving through a tunnel at speed for 20 minutes, the power cars have only a very small windshield/screen when compared to other high-speed trains and TGV models.

Accidents and incidents
, there has only been one major accident involving a service operated by Eurostar. On 5 June 2000, a Eurostar train travelling from Paris to London derailed on the LGV Nord high-speed line while travelling at a speed of 290 km/h. Fourteen people were treated for light injuries or shock, with no major injures or fatalities. The articulated nature of the trainset was credited with maintaining stability during the incident and all of the train stayed upright. After investigation, the incident was blamed on a component of the transmission system between the electric motors and axles coming loose. To reduce the unsprung mass, TGV-style trains have the motors attached to the train rather than the bogies. In order for the train to still be able to go around curves, an extra sliding "tripod" assembly is used, which is what became dislodged.

There have been several minor incidents with a few Eurostar services. In October 1994, there were teething problems relating to the start of operations. The first preview train, carrying 400 members of the press and media, was delayed for two hours owing to technical issues. On 29 May 2002 a Eurostar train was initially sent down a wrong line—towards London Victoria railway station instead of London Waterloo—causing the service to arrive 25 minutes late. A signalling error that lead to the incorrect routeing was stated to have caused "no risk" as a result.

Record runs
On 30 July 2003, on the opening press run of High Speed 1 section 1, Eurostar 3313/14 set a new British rail speed record of 334.7 kilometres per hour (208 mph), breaking the previous-held record of 259.5 kilometres per hour (162.2 mph) set by an Advanced Passenger Train on 20 December 1979.

On 16 May 2006 a Eurostar set a new record for the longest non-stop high speed journey, when set 3209/10 made the 1421 km journey from London to Cannes in 7 hours 25 minutes. This was a result of Eurostar's partnership with the Da Vinci Code film. The train carried stars Tom Hanks, Audrey Tautou and director Ron Howard, who had jointly named the train The Da Vinci Code prior to departing London on its way to the film premiere at the Cannes Film Festival.

On 4 September 2007 the first revenue Eurostar train to use the new Channel Tunnel Rail Link to St Pancras railway station set a new speed record for rail travel between London and Paris. The first train left Paris at 09:44 BST and arrived at St. Pancras two hours, three minutes and 39 seconds later. Officials aboard the inaugural train recorded speeds of up to 325 km/h in France and 314 km/h in Britain.

Exhibitions
On several occasions, Class 373 power cars and sets have appeared at special events and displays on behalf of Eurostar; such as at Rotterdam Centraal Station on 6 April 1996, Berlin-Grunewald station for Eurailspeed 1998, Madrid Chamartín railway station for Eurorailspeed 2002 and at the York National Railway Museum for the Railfest 200 celebrations in 2004.

To celebrate ten years of the Eurostar service in operation, a barge was floated down the River Thames in London on 16 November 2004, with a power car onboard, that had been specially painted by Ben Langlands and Nikki Bell. Named "Language of Places on Eurostar" by Langlands and Bell, the artwork piece consisted of the three-letter "destination codes for all the places Eurostar goes to or connects to". The barge's voyage took it under Tower Bridge, past the Houses of Parliament and was moored for a period beside the museum-warship HMS Belfast.