# RER NG

RER NG (French: RER Nouvelle Génération, English: RER New Generation), also known as the X'Trapolis Cityduplex and classified as Class Z 58000 and Class Z 58500, is a double-deck, dual-voltage electric multiple unit trainset that operates on line D and line E of the Réseau Express Régional (RER), a hybrid suburban commuter and rapid transit system serving Paris and its Île-de-France suburbs. The trainsets have gradually been introduced to service since November 2023 on line E, and since December 2024 on line D.
The trainsets are being built by a consortium of French manufacturer Alstom and Canadian conglomerate Bombardier. The RER NG is part of Alstom's X'Trapolis Duplex platform and is an evolution of several generations of double-deck trainsets built by the consortium, including the Z 2N, MI 2N, and MI 09 series.
Final assembly takes place at the Alstom factory in Valenciennes and the former Bombardier plant in Crespin, while the car bodies are being manufactured at the Alstom plant in Česká Lípa, Czech Republic.

## History

As Île-de-France Mobilités and SNCF prepared to extend the RER E line west across Paris, the agencies issued a invitation to tender for new trainsets for the line and overall fleet replacement. Several manufacturers responded including a consortium of Alstom and Bombardier, CAF, and Siemens.
Ultimately, the €3.75 billion contract was awarded to Alstom and Bombardier on 6 January 2017. The consortium had previously built several generations of double-deck trainsets, including the Z 2N, MI 2N, and MI 09 series. Similar to those earlier contracts, Alstom would build the two end cars, which contain the cabs, while Bombardier manufactured the intermediate cars. The contract will supply 255 trainsets, 130 for the RER E and 125 for fleet replacement, which are planned to be assigned to the RER D, replacing older trainsets.
In October 2018, Île-de-France Mobilités purchased an additional 64 trainsets for fleet replacement, increasing the total contract to 371 trainsets.
In spring 2020, the first trainset started testing in the Czech Republic.
On April 26, 2023, Alstom announced the exercise of a first option for the supply of 60 additional trainsets, bringing orders to 131 trainsets.
The first six-car Z 58000 trainsets were introduced to regular passenger service on line E of the RER on 13 November 2023. Introduction of seven-car Z 58500 trainsets on line D followed on 13 December 2024.

## Description

The design of the RER NG is similar to Bombardier's Regio 2N trainsets with a mix of single and double-deck cars. The single-level end cars are designed to offer level boarding that accommodates disabled passengers who are unable to use stairs and standing passengers traveling short distances. The double-deck intermediate cars accommodate seated passengers traveling longer distances.
The RER NG trainsets are being built in two different configurations:
* Class Z 58000: 130 six-car trainsets for the RER line E consisting of two single-level cars with cabs and motors, two bi-level cars with motors, and two unpowered bi-level cars at a total length of 112 metres (367 ft).
* Class Z 58500: 125 seven-car trainsets for the RER line D consisting of two single-level cars with cabs and motors, two bi-level cars with motors, and three unpowered bi-level cars at a total length of 130 metres (430 ft).
The single-level end cars are 20 metres (65 ft 7 in) long, with two doors per side (one 1.3 metres (4 ft 3 in) wide and one 1.95 metres (6 ft 5 in) wide). The double-deck intermediate cars each have two doors per side. The doors located just behind the driving cabs are fitted with gap fillers to enable level boarding for passengers using a mobility device, like a wheelchair.
All trainsets have open-gangways allowing passengers to travel from one end of the trainset to the other, allowing more an even distribution of passengers on board, reducing crowding during peak periods. Unlike some other open-gangway trainsets, the RER NG will not use a jacobs bogie between cars, but rather a conventional architecture with two bogies on each car.
Like all RER trains since the MI 84, the RER NG is required to meet strict acceleration standards, being able to fully depart a 225-metre (738 ft 2 in) platform in 23 seconds. Despite the fact that the RER NG is heavier and up to 17 metres (55 ft 9 in) longer than a MI 84, it is able to meet this standard with its eight or ten motorised bogies.
The maximum top speed for the RER NG in service is 140 kilometres per hour (87 mph). During testing, speeds of 160 kilometres per hour (99 mph) were reached.
The RER NG trainsets are equipped with the NExTEO system for operating in the tunnels of the central section on the RER E, allowing for travel speeds at up to 120 kilometres per hour (75 mph) in that section.

## Formations

As of 1 April 2022, at least 3 Z58000 trainsets were in tests.
The six-car class Z 58000 trainsets are in operation on RER line E. They are based at the Noisy-le-Sec and Nanterre SNCF depots.
As shown below, they are formed of four motorised cars and two non-powered trailer cars.
| RER E | ← Haussmann–Saint-Lazare (Paris)—Chelles–Gournay/Tournan → | ← Haussmann–Saint-Lazare (Paris)—Chelles–Gournay/Tournan → | ← Haussmann–Saint-Lazare (Paris)—Chelles–Gournay/Tournan → | ← Haussmann–Saint-Lazare (Paris)—Chelles–Gournay/Tournan → | ← Haussmann–Saint-Lazare (Paris)—Chelles–Gournay/Tournan → | ← Haussmann–Saint-Lazare (Paris)—Chelles–Gournay/Tournan → |
| Car No. | 1 > | 2 | 3 | 4 | 5 | < 6 |
| Type | Motor | Motor | Trailer | Trailer | Motor | Motor |
* < or > show a pantograph. Cars 1 and 6 are each equipped with one pantograph.
* All cars are connected by gangway.
The seven-car Class Z 58500 trainsets in operation on RER line D. They are based at the Villeneuve and Joncherolles SNCF depots.
As shown below, they are formed of four motorised cars and three non-powered trailer cars.
| RER D | ← CreilCorbeil-Essonnes/Malesherbes/Melun → | ← CreilCorbeil-Essonnes/Malesherbes/Melun → | ← CreilCorbeil-Essonnes/Malesherbes/Melun → | ← CreilCorbeil-Essonnes/Malesherbes/Melun → | ← CreilCorbeil-Essonnes/Malesherbes/Melun → | ← CreilCorbeil-Essonnes/Malesherbes/Melun → | ← CreilCorbeil-Essonnes/Malesherbes/Melun → |
| Car No. | 1 > | 2 | 3 | 4 | 5 | 6 | < 7 |
| Type | Motor | Motor | Trailer | Trailer | Trailer | Motor | Motor |
* < or > show a pantograph. Cars 1 and 7 are each equipped with one pantograph.
* All cars are connected by gangway.