HJ2392 SNCF, diesel locomotive class BB 66047, 2nd subseries, blue/yellow livery, period III

After electrification of high-traffic lines, SNCF continued to modernise its network by replacing steam locomotives with diesel locomotives.

In 1958, SNCF launched the construction of a series of 318 medium-powered diesel-electric machines, suitable for multiple unit operation for the traction of freight and passenger trains. The design of these machines is simple with a single driver's cab framed by an extended cab cover at the front of the engine-generator set and a short cab cover at the rear. The characteristic shape of the cab roof is due to the installation of mufflers in the ceiling. Initially designated 040 DG, then renamed BB 66000 from January 1962.

There are three tranches of these locomotives:

• BB 66001 to BB 66040, originally with a gangway their original speed was limited to 105 km/h and then increased to 120 km/h will be increased after modification to 120 km/h like the other units
• BB 66041 to BB 66188
• BB 66189 to BB 66318

In order to deal with its ageing fleet of diesel locomotives used to pull freight trains, SNCF is modernising its robust BB 66000 locomotives from 2005 until the end of 2009 instead of ordering new ones. This modernisation concerns only 91 machines from the third batch (BB 66189 to BB 66318), and includes the installation of a new, more fuel-efficient and less polluting 1040 kW MTU diesel engine.

The modernised freight locomotives were given the same green-white and grey livery as the BB 66400/69400, while the INFRA locomotives were given a blue livery and then gradually the new yellow INFRA livery. The modernised vehicles are registered BB 69 (...) with the last three digits of the original registration number to which is added the prefix "4" or "6" according to the activity to which they are attached ("4" for the FRET activity or "6" for the INFRA activity in charge of track and infrastructure maintenance).

The capacity of the fuel tank is 3000 litres, the range is about 1000 km. The mass is 72 tonnes, the length is 14,898 m, the minimum curve radius is 80 m, the maximum speed in service is 120 km/h.

As of the end of September 2019, 64 of the 91 modernised machines remain in service, mainly used by the INFRA activity. The BB 69216 was put into service on 28 November 1965 under the registration BB 66216, then renumbered as BB 469216 on 11 June 2005. This locomotive is managed by the STF (Supervision technique de flotte) Infrarail de Chalindrey (SLI).