SNCF TGV Duplex

SNCF TGV Duplex
TGV Duplex at 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 (2 power cars, 8 passenger cars)
Capacity	508 seats
Operator(s)	SNCF
Specifications
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 Dasye: 8 Alstom 6 FHA 1,160 kW (1,560 hp) AC Asynchronous Motors
Power output	3,680 kW (4,930 hp) Duplex & Dasye; under 1.5 kV DC supply 8,800 kW (11,800 hp) Duplex; under 25 kV AC supply 9,280 kW (12,440 hp) Dasye; 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	1,435 mm (4 ft 8 1⁄2 in) standard 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. It 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 increases the passenger capacity. While the TGV Duplex started as a small component of the TGV fleet, it has become one of the system's workhorses.

The LGV Sud-Est from Paris to Lyon is the busiest high-speed line in France. After its opening in 1981 it rapidly reached capacity. Several options were available to increase capacity. The separation between trains was reduced to three minutes on some TGV lines, but the increasingly complex signalling systems, and high-performance brakes (to reduce braking distance) required, limited this option. Another option is to widen the train but is generally not practicable due to loading gauge restrictions. Running two trainsets coupled together in multiple-unit (MU) configuration provides extra capacity, but required very long station platforms. Given length and width restrictions, the remaining option is to adopt a bi-level configuration, with seating on two levels, adding 45% more passenger capacity. TGV Duplex sets are often run with a single deck Réseau set or another Duplex set.

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 contract was finalized in early 1991, at which point the official order was made. The first tests of a bi-level trainset in were 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 not ready. The first Duplex power car was mated to the bi-level trailers on 21 June 1995.