SNCF Class Z 20900

Z 20900
A Z 20900 trainset operating on the RER C line at Neuilly – Porte Maillot station
In service	2001–present
Manufacturer	Alstom and Bombardier[1]
Family name	Z 2N series, X'Trapolis Tagus
Replaced	Z5300
Constructed	2001–2004
Entered service	12 June 2001
Refurbished	2019–2023
Number in service	54 trainsets (216 cars)
Formation	4 cars per trainset
Fleet numbers	Z 20901/2 to 21007/8
Operators	SNCF Transilien
Depots	Les Ardoines
Lines served
Specifications
Car body construction	Copper steel Stainless steel
Train length	103.508 m (339 ft 7.1 in)
Width	2.82 m (9 ft 3 in)
Height	4.32 m (14 ft 2 in)
Doors	2 pairs per side, per car
Maximum speed	140 km/h (87 mph)
Weight	245,000 kg (540,000 lb)
Traction system	Alstom OniX IGBT–VVVF
Traction motors	8 × 4 FXA 2858 (asynchronous motors)
Power output	3,464 kW (4,645 hp)
Transmission	Gear wheel, hollow shaft and cardan shaft, ratio : 4.18
Acceleration	1 m/s2 (3.3 ft/s2)
Deceleration	1.05 m/s2 (3.4 ft/s2) (service) 1.10 m/s2 (3.6 ft/s2) (emergency)
Electric system(s)	Overhead line:     25 kV 50 Hz AC     1,500 V DC
Current collection	Pantograph Type AM18
Bogies	type Y401(motor)/Y30PL(trailer), H shape
Braking system(s)	Electrodynamic
Safety system(s)	Crocodile, KVB
Coupling system	Scharfenberg type
Multiple working	Other Z 2N series trains (Z 5600, Z 8800, Z 20500, Z 20900)
Track gauge	1,435 mm (4 ft 8+1⁄2 in) standard gauge

The SNCF Class Z 20900 is a double-deck, dual-voltage electric multiple unit (EMU) trainset operated on RER C of the Réseau Express Régional (RER), a hybrid suburban commuter and rapid transit system serving Paris and its Île-de-France suburbs.

Fifty-four four-car trainsets were built by a consortium of Alstom and Bombardier Transportation between 2001 and 2004. The first set entered passenger service in July 2001. They were the final trains produced in the Z 2N series, which had been developed over several generations. Their introduction enabled the withdrawal of older rolling stock from RER C.

SNCF ordered the Class Z 20900 in late 1998 to complete the RER C fleet and replace the last 42 Class Z 5300 units still in service. Based on the earlier Class Z 20500 design, the Z 20900 introduced a number of refinements, including a fixed four-car formation, upgraded seating with armrests, and air-conditioned interiors with tinted windows. The two central cars are connected by gangways to improve passenger flow, and door operations are accompanied by both visual and audible warnings. The trains use the Alstom OniX (French: Onduleur à Intégration eXceptionnelle, lit. 'exceptional integration inverter') traction system with insulated-gate bipolar transistor (IGBT) and variable-frequency drive (VVVF) components, and are equipped with a security feature allowing passenger areas in the power cars to be locked during late-night operations. Each power car (ZB) contains 82 seats, while each trailer car (ZRB) contains 96 seats and is fitted with a toilet.

The first Class Z 20900 sets entered service on RER C in July 2001, with deliveries continuing until 2004. Their arrival enabled the withdrawal of the remaining Z 5300 units from the line and, through fleet reassignments, the retirement of the oldest Class Z 6100 units in the northern suburbs. Between 2001 and 2012, twelve sets were allocated to Transilien Line H. The OniX traction system, first tested on unit Z 20887–20888 of the Z 20500 series, is also used in the Class Z 23500 (TER 2N) and CP 3500 series.

The Class Z 20900 fleet consists of 54 trainsets, numbered 201 A to 254 A, with the suffix "A" indicating asynchronous motor.

As of 1 January 2022, all 54 trainsets are based at the Les Ardoines SNCF depot and are assigned to the RER C. Each set is formed in a 2M2T configuration, comprising two motored cars and two non-powered trailer cars.

• < or > show a pantograph. Cars 1 and 4 are each equipped with one pantograph.
• Cars 2 and 3 are connected by a gangway.

Wikimedia Commons has media related to SNCF Class Z 20900.

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  Z 20900 in the SNCF livery
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  Z 20900 in the navy blue Transilien livery
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  Z 20900 interior, upper deck (original)
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  Z 20900 interior, the mid-deck wide entry, and stairs to lower deck, as seen from the upper deck
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  Operators compartment
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  Z 20900 interior (refurbished)
• Z 20900, with SIVE and the luminous and audible warning device for the closing of the doors in operation

• Redoutey, Denis (2007). Le matériel moteur de la SNCF. La vie du Rail. ISBN 978-2-915034-65-3.
• Bernard Collardey, Les trains de banlieue, tome II, Éd. La Vie du Rail, 1999, 335 p. ISBN 2902808763
• Le parc Z 20900, on metro-pole.net via web.archive.org, 1er janvier 2008(in french)
• Revue bimestrielle Voies Ferrées, Le matériel moteur de la SNCF, en plusieurs articles sur plusieurs numéros par année. (in french)
• Revue mensuelle Rail Passion, État trimestriel du matériel moteur SNCF, un article par trimestre. (in french)
• Lydie, « Le SIVE, ou l'amélioration de l'information à bord des RER C » [archive], Le blog du RER C, 24 octobre 2017 (consulté le 3 novembre 2017).(in french)
• « [Z 5600 / Z 8800 / Z 20500 / Z 20900 (Z2N)] Sujet Officiel » [archive], sur Le web des cheminots, article du 22 avril 2018 (consulté le 24 avril 2018) : « La 1ère à sortir du Technicentre de Saint Pierre des Corps est la Z 20905/06 (203A). Cette dernière est ressortie avec la même livrée qu'une partie des Z2N de la ligne C, à base de rouge "carmillon" de la SNCF et "vif argent" du STIF ».(in french)
• Marc Carémantrant, « Les débuts des Z 20900 » dans Rail Passion no 51, septembre 2001, pp. 12 et 13.(in french)
• Bernard Collardey, Les trains de banlieue, tome II, p. 302.(in french)
• « [Z 5600 / Z 8800 / Z 20500 / Z 20900 (Z2N)] Sujet Officiel » [archive], sur Le Web des Cheminots (consulté le 11 juin 2018).(in french)