SNCF Class Z 20900

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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 collector(s)	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 trainset that is operated on line C of the Réseau Express Régional (RER), a hybrid suburban commuter and rapid transit system serving Paris and its Île-de-France suburbs.

The 54 four-car trains were built by a consortium of French manufacturer Alstom and Canadian conglomerate Bombardier between 2001 and 2004. The first set was placed into regular passenger service in July 2001.

They are the final equipment produced as part of the Z 2N series of trainsets, which were continuously improved over several generations.

The introduction of the Z 20900 allowed for the oldest equipment on the RER C to be scrapped.

SNCF ordered the Class Z 20900 at the end of 1998 to complete the rolling stock fleet of line C and to replace the last 42 Z 5300 units still in service. The design of 54 four-car trainsets would be based on the earlier Z 20500.They are distinguished in particular by :

• large, much more comfortable seats with armrests
• their fixed composition at 4 cars
• the Alstom OniX traction chain (Onduleur à Intégration eXceptionnelle) based on IGBT components.
• the installation of the end-of-evening security system by the possibility of neutralizing the passenger spaces of the power cars
• air conditioning and tinted windows
• the inter-circulation between the two central car;
• luminous and audible warning device for the closing of the doors

The two power cars (ZB) have 82 seats while the two trailers (ZRB) each have 96, as well as a toilet.

In order to complete the rolling stock of line C of the RER, and to eliminate from the line the last Z 5300 units still in service, the SNCF ordered new Z 20500 type trainsets at the end of 1998, but with various engine and amenagement upgrades. These new components were delivered from July 2001 to 2004 and were numbered Z 20900. Their delivery made it possible to eliminate, by shifting, the first sub-series of Z 6100 in the northern suburbs. Between 2001 and 2012, 12 trains were used for the line H.

The OniX traction motor was tested on unit Z 20887-20888(Z20500 series), and is used on all trains of this series. This propulsion system is also used in Z 23500 (TER 2N) and CP 3500.

As of 1 January 2022^[update], 54 Z20900 trainsets are based at the Les Ardoines SNCF depot.

As shown below, they are formed with two motored cars and two non-powered (trailer) cars (2M2T).

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

The number of Z 20900 trainsets is 54, numbered 201 A to 254 A (the index "A" indicating asynchronous motorization). All are in service on line C of the Île-de-France RER and are managed by the technical supervision of the line C fleet (SLC).

• Listing Fleet Z20900 (in french)

Wikimedia Commons has media related to SNCF Class Z 20900.

• 
  Z 20900 in the SNCF livery
• 
  Z 20900 in the navy blue Transilien livery
• 
  Z 20900 interior, upper deck (original)
• 
  Z 20900 interior, the mid-deck wide entry, and stairs to lower deck, as seen from the upper deck
• 
  Operators compartment
• 
  Z 20900 interior (refurbished)

• 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, « https://malignec.transilien.com/2017/10/24/sive/ » [archive], Le blog du RER C, 24 octobre 2017 (consulté le 3 novembre 2017).(in french)
• « https://www.cheminots.net/forum/topic/24494-z-5600-z-8800-z-20500-z-20900-z2n-sujet-officiel/page/82/?tab=comments#comment-821264 » [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)
• « https://www.cheminots.net/forum/topic/24494-z-5600-z-8800-z-20500-z-20900-z2n-sujet-officiel/page/82/ » [archive], sur Le Web des Cheminots (consulté le 11 juin 2018).(in french)