TGV Duplex

TGV Duplex

This article was originally based on material from TGVweb, which is licensed under the GFDL.
Paris-Gare de Lyon.
First class on a TGV Duplex
Manufacturer GEC-Alsthom, Alstom
Family name TGV
Constructed 1995 - 2012
Number built 89 trainsets (Duplex)
52 trainsets (Dasye)
19 trainsets 6xx (modification)
Formation 10 cars
Capacity 508 seats
Operator SNCF
Train length 200 m (656 ft)
Height 4,320 mm (14 ft 2 in)
Maximum speed 320 km/h (199 mph)
Weight 380 t (374 long tons; 419 short tons)
Traction system Duplex: 8 Alstom SM 47 1,100 kW (1,500 hp) AC Synchronous Motors
Dayse: 8 Alstom 6 FHA 1,160 kW (1,560 hp) AC Asynchronous Motors
Power output 3,680 kW (4,930 hp)
Duplex & Dayse; under 1.5 kV DC supply
8,800 kW (11,800 hp)
Duplex; under 25 kV AC supply
9,280 kW (12,440 hp)
Dayse; under 25 kV AC supply
Electric system(s) 25 kV 50 Hz AC
1.5 kV DC
Overhead catenary
Current collection method Pantograph
UIC classification Bo'Bo'+2'2'2'2'2'2'2'2'2'+Bo'Bo'
Braking system(s) Regenerative & Pneumatic
Multiple working Up to two units
Track gauge

The TGV Duplex is a French high-speed train of the TGV family, manufactured by Alstom, and operated by the French national railway company SNCF. It is unique among TGV trains in that it features bi-level carriages. The Duplex inaugurated the third generation of TGV trainsets, and was specially designed to increase capacity on high-speed lines with saturated traffic. With two seating levels and a seating capacity of 508 passengers, the Duplex maximizes the number of passengers carried in one trainset. While the TGV Duplex started as a small component of the TGV fleet, it has become one of the system's main workhorses.

Why the duplex?

The LGV Sud-Est from Paris to Lyon is the busiest high-speed line in France, and after its opening in 1981 it rapidly reached capacity. When a railway line reaches its saturation limit, there are several options available to increase capacity. One way is to reduce train headways (the time between each train), i.e. to fit more trains onto the line at once. To achieve this, increasingly complex signalling systems and high-performance brakes (to reduce braking distance) are required. While these avenues have already been pursued to some extent by SNCF (headways have been reduced to three minutes on some TGV lines), the technical difficulties of continually improving signalling and braking make other solutions to the problem more attractive. Another option is to change the size of the train. Making the train wider is generally not practicable due to gauging restrictions. Running two trainsets coupled together in multiple-unit (MU) configuration provides extra capacity, but not enough in this case, and had the added disadvantage of requiring very long station platforms. If a train cannot be made longer or wider, then the remaining option is to make it taller, resulting in a bi-level configuration, with passenger seating on two levels, and 45% more passenger capacity than an equivalent single-level TGV. In addition, TGV Duplex sets are often run with a single deck Réseau set or another Duplex set.

Development history

The Duplex feasibility study was completed in 1987. In 1988, a full-scale mockup was built to gauge customer reactions to the bi-level concept, traditionally associated with commuter and regional rail rather than with high-speed intercity trains. A TGV Sud-Est trailer was tested in revenue service with the inside furnished to simulate the lower floor of a bi-level arrangement, and later that year another TGV Sud-Est was modified to study the dynamic behavior of a train with a higher center of gravity. Discussions with GEC-Alsthom began soon after, and in July 1990 the company won the contract to build the "TGV-2N", as it was then known. The details of the contract were not put in place until early 1991, at which point the official order was made. Since then, technological hurdles have been overcome in a four-year process that led to the first tests of a bi-level trainset in November 1994. Soon after their first run, the first rake of eight trailers was tested at 290 km/h (180 mph) on the Sud-Est line. The trainset was powered by TGV Réseau power cars at the time, as the Duplex power cars were still undergoing development. The first Duplex power car was mated to the bi-level trailers on 21 June 1995.


Perhaps the most important innovation is the efficiency of the Duplex design. Comparing an original TGV Sud-Est and a Duplex trainset shows that the double-decker design has improvements in both power-to-weight ratio and the weight-per-seat overhead:

Power-to-weight ratio
TGV Sud-Est 17 1.10 18.34
TGV Duplex 23 0.7 16.15

In this comparison, "power" refers to installed power, not all of which is used when operating.

  • Aluminium bodies - the strict requirement of a 17-tonne (16.7-long-ton; 18.7-short-ton) axle load limit made it imperative to cut down on weight, wherever possible. Extruded aluminum construction made possible a 20% reduction in the weight of the structure.
  • Improved styling and aerodynamics - the nose of the power units and the gap between trailers were improved such that a Duplex train at cruise speed of 300 km/h (186 mph) experiences only 4% more drag than a single-level TGV. The nose, the first significant departure from Cooper's original design, was styled by industrial designer Roger Tallon, as was the rest of the trainset.
  • Crashworthiness - crush zones and rigid passenger compartments ensure maximum safety in the event of a collision. The power units' frame is designed to take a (steady-state) 500 tonnes (490 long tons; 550 short tons) of force frontal load, and features structural fuses to absorb impact energy.
  • Active pantograph - the Faiveley CX used on the Duplex has a pneumatically actuated active control system. Two small gas cylinders in the wiper armature can tune the stiffness of the pantograph's upper stage, to optimize contact at any speed.
  • All wheel disc brakes - earlier TGVs (including Eurostar) used disc brakes only on unpowered axles. Weight gains on the Duplex power units allowed the installation of disc brakes directly on the wheels of powered axles (so-called "cheek discs"), instead of using the traditional tread brakes. This does not greatly improve braking performance, but it leaves the wheel tread smooth and considerably reduces rolling noise.
  • Quiet roof fans - the cooling fans in TGV power units produce the most noticeable sound (a loud hum) when the train is in a station. The fans, located in the roof of the unit, have been redesigned to be quieter.

Réseau Duplex

Also called Réseau Duplex, they take the serial number 600 (601-619). This version came to existence when the carriages of nineteen TGV-Réseau sets were used to create the TGV POS sets. The Réseau powercars of these sets then, with only some aerodynamic adjustments, joined new Duplex sets. They are the first series of "inter-recoupled series" TGV achieved a sustainable basis by SNCF.

In fact, the railways had changed an order for 19 Duplex as follows:

  • 19 sets of 8 Duplex-carriages, identical to the original TGV Duplex (Series 200), to be powered by the 38 surplus TGV Réseau powercars.
  • 38 new tricourant powercars, based on the Duplex-version, making them suitable for use on networks of Deutsche Bahn and Swiss Federal Railways. These were joined to the nineteen sets of Réseau carriages, renovated by Christian Lacroix, becoming the series "4400" or TGV POS.

They are identical to the whole Duplex family. It is these that form new motor Duplex Network. Also called "duplex" (with a "small to"), they are the number of 19, numbered from 601 to 619, all connected in Technicentre South-East Europe. This solution of "tinkering" has allowed the railways to maintain the pace of delivery of Duplex which was considered a priority.

Dasye and Euroduplex

Dasye is a contraction of Duplex Asynchronous ERTMS. The series has a similar design to the classic series Duplex, but internal changes have been made.

These trains are rolling the serial number "700". They feature a new powertrain with asynchronous motor of the same type as that of the motor TGV POS, and they also boarded the ERTMS. Train 701 was delivered in late 2006 and joined with section 619 Duplex Network (section delivered for processing and network duplex POS) for tests of preproduction. The train was delivered 701 complete on 14/02/2008.

In June 2007, the SNCF placed a large order to Alstom for 25 additional Dasye Duplex trainsets. Part of this order is for 55 trains tricourant a new type high-speed trains and 2 levels (TGV 2N2) and a reserve engine, permitting the relationship between France and Germany or Switzerland; Alstom call this "Euroduplex".

These trains will strengthen the connections to the south, including the LGV Perpignan–Figueres, allowing the transit joint Franco-Spanish, completed in February 2009, used from December 2010 to two round trip Paris - Figueres and will be fully opened in 2013 for journeys Paris - Barcelona unchanged. This new infrastructure is innovative in France, because it is designed for high-speed train traffic, AVE and train Freight. It saves huge on travel time. The trains 200 and 600 series will not go to Spain because they are not equipped with ERTMS.

95 Euroduplex trains will also be used on the recently opened Rhine-Rhône; the original 55, plus an additional 40 ordered by SNCF in April 2012.[1]

The interior trim has reams of new colors (blue) and new interior (with electrical outlets at the seat in the 1st and 2nd class), the remaining facilities is very similar to those of duplex and an indicator of the speed of a TGV been installed in the car bar, above the bar.


Main article: Eurotrain

Eurotrain was a consortium formed by Siemens and GEC-Alsthom (today Alstom) in 1996 to market high-speed rail technology in Asia. In 1997, it was one of two competitors to supply the core system of Taiwan High Speed Rail (THSR), and was awarded the status of preferred bidder by concessionaire THSRC.[2]

In early 1998, the two companies created a demonstration train by combining cars of three existing French and German high-speed trains: the intermediate cars of TGV Duplex trainset #224 was joined with German Railways ICE 2 powerheads 402 042 and 402 046 at the two ends. On 4 May 1998, the Eurotrain demonstration train made a presentation run on the Hanover–Würzburg high-speed railway in Germany, achieving a maximum speed of 316 km/h (196 mph).[3][4]

In December 2000, THSRC decided to award the contract to the rival Taiwan Shinkansen Consortium,[2] leading to a legal battle[5] ending in damage payments for Eurotrain in 2004.[6][7]

See also