SNCF's X 2400 are a French class of railcars.^[1] The 79 XABDP 2400, unifiés 600 PS (440 kW) were built from 1951 to 1955. They were capable of carrying 12 passengers in 1st class and 56 in 2nd class,^[2] they were 27 m (88 ft 7 in) long and capable of reaching a top speed of 120 km/h (75 mph). The railcars were often coupled to trailers of coupled to other units.

SNCF X 2400
The X 2426 at Pont-Audemer
In service	1951 to 1989
Manufacturer	Régie Renault/Decauville
Constructed	1951 to 1955
Number built	79
Number in service	0
Number preserved	11
Formation	Single car
Fleet numbers	X 2401 to X 2479
Capacity	12 first class 56 second class
Operators	SNCF/TER
Specifications
Car length	27.73 m (91 ft 0 in)
Maximum speed	120 km/h (75 mph)
Weight	43 tonnes (42 long tons; 47 short tons) in working order
Prime mover(s)	Renault 517, 2 off
Engine type	Diesel
Power output	456 kW (612 hp)
Transmission	Mechanical
Track gauge	1,435 mm (4 ft 8+1⁄2 in)

The class was put into service along the X 3800, Picasso. These 300 PS (220 kW) railcars facilitated the phasing out of steam traction and to renew aging railcar stock. The class was first allocated to Limoges and onto the lines of the Massif Central, coupled to XR 8000 trailers. The X 2400 was quickly accompanied by the X 2800 railcars, equipped with one engine only, but more powerful.

The maintenance cost of the X 2400 was greater than the one-engined X 2800 and so the class was moved to Rennes. The arrival of the X 2100 and X 2200 railcars precipitated the retirement of the X 2400, the last 2400 retiring in 1989.

The X 2464 was withdrawn from service in 1988 and was modified into a measurement train. It was painted into the Corail livery of dark grey, orange and white. Twelve railcars have been preserved.

Two sub-classes of X 2400 exist:

• XABDP 2401 to 2469 with a weight of 43 t (42 long tons; 47 short tons), two 517G Renault engines with 250 kW (340 PS) (340 ch) output.
• XABDP 2470 to 2479 with a weight of 44.5 t (43.8 long tons; 49.1 short tons), two Saurer engines with 235 kW (320 PS) (320 ch) output.