Z 23000

In 1930, the CMP ordered the Z 23000, intended to be suitable for reliable and efficient suburban service on the Sceaux Line, which was being radically modernized and electrified at the time of the order. These new railcars introduced several new features, including four pairs of doors per side (similar to equipment used on the Paris Métro) allowing for faster passenger boarding at stations, high platform boarding, longer cars without significant gaps at curved platforms, light construction for faster acceleration and simple, reliable electrical equipment. The railcars were equipped with a pantograph for capturing the 1.5 kV DC power from overhead catenary lines.

The Z 23000 railcars were ordered in several installments: the first phase in 1934, built by the Forges et ateliers de constructions électriques de Jeumont company, followed by a second order in 1937, a third in 1942 and a fourth in June 1950. Similarly, the commercial implementation of the railcars was also rolled out in multiple phases between November 1937 and December 1938 (for the first two series) on the Sceaux Line, which had just been modernised and electrified. Two final orders were placed in 1959 for 21 engines and in 1961 for a further 25. A total of 148 railcars were built over a period of almost 30 years.

The Z 23000 also played a part in the integration of the Sceaux and the RER B Lines in 1977, initially extending to Châtelet-Les Halles. They received some technical improvements at this time to accommodate the steeper gradients on the new tracks for the RER B. The line has a north–south ramp with a gradient of 40 per thousand. RATP engineers tested the railcars on the Line A ramp between Le Vésinet et Saint-Germain-en-Laye. The brakes needed replacing, and the wheels were upgraded to monoblock (there were also some spoke wheels.) However the Z 23000, designed for a continuous 1500 V current, had limited functionality on the RER B because north of Gare du Nord the line was electrified using SNCF's incompatible 25 kV AC system. Because of this, the RATP ordered the MI 79 (French: Matériel d'Interconnexion de 1979, English: interconnection rolling stock of 1979) trainsets for the RER B, which could use both electric systems (interconnect).

Z 23461 preserved at Cité du train in Mulhouse, in the original "duck blue" livery.

Z 23237 preserved at Villeneuve-Saint-Georges, in the later "celtic green" livery.

The Z 23461 is preserved in its original "duck blue" livery at the Cité du train museum in Mulhouse.

The RATP preserves five railcars in the Villeneuve-Saint-Georges reserve. Z 23237 has been restored into the "celtic green" livery, while Z 23342, Z 23312, Z 23326 and Z 23328 were preserved in the same blue and gray livery they had when they were retired.

• 
  MS 61 (left), Z 23237 (right) preserved at Villeneuve-Saint-Georges
• 
  Control cab
• 
  Route map
• 
  First class seat
• 
  Chandelier