Z 23000

The Z 23000 were railcars of the Compagnie du chemin de fer métropolitain de Paris (CMP). The trains, also known as the "automotrices Z" (English: self-propelled Z), were ordered from 1934 to provide service on the Ligne de Sceaux to the southern suburbs of Paris, which was heavily modernized and electrified by 1937. Each car in the series was identical, with all being motorized. The Z 23000 was the first generation of modern self-propelled equipment intended to serve a future regional metro network, which would not be created until forty years later under the name Reseau Express Regional (RER).

Z 23000
Z 23000 train at Laplace station, c. 1980
2nd class section of preserved Z 23000 train
Manufacturer	Brissonneau et Lotz, CFMCF, CGC, CIMT and Decauville
Scrapped	1987
Number built	150 cars
Capacity	84 seats (56 fixed, 28 folding), 177 maximum
Operator(s)	CMP (before 1949) RATP (after 1949)
Line(s) served	Ligne de Sceaux
Specifications
Car length	20.7 m (67 ft 11 in)
Width	3.2 m (10 ft 6 in)
Height	4.4 m (14 ft 5 in)
Floor height	1.2 m (3 ft 11 in)
Doors	4 pairs per side, per car
Wheel diameter	1.1 m (3 ft 7 in)
Maximum speed	80 km/h (50 mph)
Weight	44,600 kg (98,300 lb)
Traction motors	2x 173.5 kW (232.7 hp) self-ventilated motors (Jeumont TC127-4)
Power output	1,390 kW (1,860 hp) (four-car train)
Acceleration	1 m/s^2 (2.2 mph/s)
Electric system(s)	1.5 kV DC overhead catenary
Current collection method	Pantograph
Track gauge	1,435 mm (4 ft 8 ^1⁄2 in) standard gauge

History

In 1930, the Compagnie du chemin de fer métropolitain de Paris (CMP) ordered the Z 23000, intended to be suitable for reliable and efficient suburban service on the Ligne de Sceaux, which was being radically modernized and electrified at the time of the order. These new cars 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 are 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, followed by a second order in 1937, a third in 1942, a fourth in June 1950, a fifth in 1959, and a sixth in 1961. A total of 160 railcars were built over a period of almost 30 years.

In the 1970s, RATP transformed the Ligne de Sceaux into line B of the new Reseau Express Regional (RER), and the Z 23000 continued to see use on the new line after brakes and wheels were upgraded to accommodate the steeper grades on the new tracks for the RER B. However the Z 23000 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).

Withdrawal

The RATP planned to withdraw the Z 23000 from service by 1983, but technical issues with the MS 61 (which would soon operate exclusively on the RER A) forced 24 trains of the then-new MI 79 to leave the RER B to make up for the shortfall. Withdrawal actually began in 1984, but the process was slowed down by a cold wave in 1985–86, which caused technical issues with the MI 79 fleet to force the surviving Z 23000 units to make up for the shortfall.[1]

The last Z 23000 train ran in revenue service on 27 February 1987, from Gare du Nord to Orsay-Ville. The withdrawal of the Z 23000 was also necessary for Saint-Michel – Notre-Dame to open (in 1988): although the Z 23000 was upgraded to climb a 4.08% gradient from Luxembourg to Châtelet, the momentum would have been lost if the train stopped at Saint Michel.[1]

After its withdrawal from service, two heritage runs took place on the southern part of the line, in 1990 and 1994.[2][3]

Order list

Order	Number purchased	Numbering	Original owner	Ordered	Builder	Delivered	Notes
1	21	Z 23221-241	CMP	1934	Decauville	1937	Delivered in "duck blue" livery
	24	Z 23242-265			CFMCF
	12	Z 23266-277			CGC
2	4	Z 23278-281	CMP	1937	CFMCF	?
	14	Z 23451-464	PO	1937		1938
3	5	Z 23282-286	CMP	1942	Brissonneau et Lotz	1947	Delivered in "celtic green" livery
	10	Z 23287-296				1949
4	14	Z 23297-310	RATP	20 June 1950	CIMT	1952	Fluorescent lights instead of chandeliers
5	21	Z 23311-331		2 October 1959		1961
6	25	Z 23332-356		1961		1962

Preserved examples

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 blue and gray livery they wore at retirement.

Photo gallery

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

References

1. "Les automotrices de la ligne de Sceaux". Transport Paris (in French). Archived from the original on 15 January 2021. Retrieved 15 January 2021.
2. Camous Joël (13 November 2016). "Automotrice Z 23000 Paris Denfert -Rochereau 1990". Retrieved 25 July 2017.
3. Celerier, Jean-Leon (7 February 2016). "Les Tramways,Métro,RER,Bus de la RATP: RER B". Les Tramways,Métro,RER,Bus de la RATP. Retrieved 2 November 2018.