SNCF Class BB 15000

The SNCF class BB 15000 is a class of 25 kV 50 Hz electric locomotives built by Alstom and MTE between 1971 and 1978. Initially 65 locomotives strong, the class was widely deployed on the whole French 25 kV network before being replaced by TGV trains when the LGV Est went into service in 2007.
In the mid-1960s, SNCF sought a new type of dual-current electric locomotives. As thyristor technology advanced rapidly, SNCF decided to adopt the new technology for a new series of locomotives, later known as the Nez Cassés (Broken Noses, due to their cab styling by Paul Arzens) or BB 4400 kW. Given that the need for pure AC-locomotives was greatest, SNCF placed an initial order of five locomotives in 1968. In 1969 a second order of 10 locomotives followed, in 1970 a third order was made for another 10 locomotives. The remaining 40 locomotives were ordered in 1973.
The first five locomotives were delivered in 1971 in the overall-green "Maurienne" livery. The rest followed between 1973 and 1978, painted in the striking TEE-Arzens livery. Initially meant to support BB16000 locomotives on eastern and northeastern lines, which could not keep up with the timetables anymore after top speed on some sections was raised to 160 km/h (99 mph), the BB15000 series would become the most important locomotives on the northern and northeast network.
After being tested on the Paris–Épernay main line in 1971, they entered revenue service from 1972. They ran mostly on the northeastern network where they hauled nearly all the principle passenger trains, including the national TEE trains Kléber and Stanislas. Some services extended to the northwest, with workings to Lille, Calais and the Belgian border at Quévy.
Services remained stable throughout the 1970s and 1980s, but the opening of the Ligne-a-Grande-Vitesse Nord in 1993 started a cascade of assignments in which the BB 15000's lost services to either dual-voltage BB 26000 locomotives or to TGV trains. Yet BB 15000 locomotives remained strong in the northeast and hauled Corail Téoz services between Paris and Strasbourg from 2003 until mid-2005, when half of the loco-hauled services were converted to TGV trainsets, albeit still running on the classic line. In mid-2006 the remainder were also converted into TGV services, leaving only some TER trains for the Lorraine and Alsace regions, and the EuroCity trains between Basel and Brussels (loco change at Luxemburg) or Paris and Frankfurt (loco change at Strasbourg).
The partial opening of the LGV Est in June 2007 meant the end of classic locomotive-hauled Intercity trains between Paris and the northeastern regions, with BB 15000 locomotives losing a great deal of importance there.
Although the end of locomotive-hauled Intercity trains in the northeast marked a downgrading of duties, it did not result in the withdrawal of the class. The remaining 60 locomotives are divided over the following three sectors:
The locomotive's body shell is shared with the other members of the "Nez Cassé" (broken nose) family (BB7200, BB22200) and is of the monocoque type.
The cab layout is shared with the BB7200 and BB22200 series and has a great deal in common with cabs of other SNCF locomotives of the 1960s. This class was also the first to introduce the VI ("Vitesse Imposée") cruise control system which is now standard on all SNCF locomotives delivered after 1971.
The electrical equipment consists of a single pantograph (type AM18U) which collects 25 kV from the catenary. Power is passed through a transformer which lowers the voltage to about 1500 V AC and a bridge rectifier controlled by thyristors rectify it into DC, which is then fed into the traction motors.
Brake equipment consists of pneumatic, electro-pneumatic, regenerative and dynamic brakes. The monomotor bogies were derived from the Y217 bogies of BB67400 locomotives and have primary (coil springs) and secondary ("sandwich" blocs) suspension.
The reliability of the locomotives is outstanding, as some locomotives have already passed the 10,000,000 km mark and have less than 2 defects per million kilometres, a number unrivaled by other similar European locomotives.
BB15000 locomotives have carried at least six different liveries:
BB 15000 locomotives were popular locomotives for conducting various experiments:
Many of the class were named after French communes, towns and cities.