SNCF Class BB 8700

The Class BB 8700 electric locomotives were rebuilt from the BB 8500 (or BB 88500) as the first subseries for the growth in Maurienne.

Class BB 8700
Type and origin Power type Electric Builder Alsthom Model BB 8500/BB 88500 Build date 1964–1972 Rebuild date 2001 Number rebuilt 20
Specifications Configuration: ​  • UIC B'B'+B'B' Gauge 1,435 mm (4 ft 8+1⁄2 in) standard gauge Wheel diameter 1,100 mm (3 ft 7.31 in) Length 14.700 m (48 ft 2+3⁄4 in) (8710-36) 14.940 m (49 ft 1⁄4 in) (8737-86) Width 3.038 m (9 ft 11.6 in) Height 4.148 m (13 ft 7.3 in) Loco weight 78.3 t (77.1 long tons; 86.3 short tons) (8710-36) 79.5 t (78.2 long tons; 87.6 short tons) (8737-86) Electric system/s 1.5 kV DC Catenary Current pickup(s) Pantograph Traction motors 2 × TAB 660 B1
Performance figures Maximum speed 100 km/h (62 mph) Power output 2,610 kW (3,550 CV; 3,500 hp) (8710-36) 2,940 kW (4,000 CV; 3,940 hp) (8737-86) Tractive effort 646 kN (145,000 lbf)
Career Operators SNCF/Fret Class BB 8700 Number in class 20 Numbers 8710–8786 Locale Culoz–Modane railway Withdrawn 2004–2005 Disposition Bank engine

Indeed, while the CC 6500 participated in this task, the reorganization of traction in Maurienne had led them to other services. Since the BB 8500 had been restricted for some years to 150 km/h (93 mph), as a result of their poor suspension and for the comfort of the drivers, it was decided to re-use twenty for Maurienne. These were renumbered as Class BB 8700.

Conversion

The conversion consisted particularly in the modification and expansion of the driving cabs at one end, by removing an air compressor. The BB 8700 were permanently coupled to run in pairs, with the unmodified cabs remaining in the middle, at the permanent coupling. Limited to 80 km/h (50 mph) and on a limited route, their discomfort was more bearable for the driving personnel.

Service

These locomotives, assigned to freight activity and attached to the Chambéry depot, were used exclusively on the Maurienne line for banking freight trains. They ran exclusively as paired units.

By 2005, the end of their career related to the reorganization of Fret SNCF and pushed them quickly towards withdrawal. Banking locomotives became less necessary with the introduction of the more powerful Class BB 36000. If the occasion arose, a Class BB 7200 was used.

See also

• List of SNCF classes

Further reading

• Defrance, Jacques (1978). Le matériel moteur de la SNCF [The SNCF engine equipment] (in French). N.M. La Vie du Rail.
• Redoutey, Denis (2007). Le matériel moteur de la SNCF [The SNCF engine equipment] (in French). La Vie du Rail. pp. 63, 366. ISBN 978-2-915034-65-3. OCLC 470662461.