Duplex

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.

Purpose
The LGV Sud-Est from Paris to Lyon is the busiest high-speed line in France.[citation needed] 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.

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

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

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

These trains are numbered in the "700" class. They feature a new powertrain with asynchronous motors of the same type as that of the motor TGV POS, and they are equipped with ERTMS. Train 701 was delivered in late 2006 and joined with the carriages of Duplex-Réseau unit 619 for pre-production tests. Unit 701 was delivered complete on 14 February 2008.

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

These trains were planned to strengthen the connections to the south, including the LGV Perpignan–Figueres, allowing joint Franco-Spanish operation. They were completed in February 2010 and used from December 2010 on two round trip Paris - Figueres and in December 2013 for Paris - Barcelona. This new infrastructure was designed for high-speed train traffic, AVE and freight. The 200 and 600 series will not enter the Spanish network, because they are not equipped with ERTMS.

Ninety-five Euroduplex trains were used on the recently opened LGV Rhin-Rhône; made up of the original fifty-five, plus an additional forty ordered by SNCF in April 2012.[1]

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