After successful tests with BB20004, prototype of BB25500 locomotives, another new series of dual-voltage locomotives was ordered by SNCF: the BB25150 and BB25200 series. These had a higher power than their predecessors, and in order to test the new parts and technology it was decided to rebuild a BB16000 locomotive into dual-voltage.
BB20005 differed from previous prototypes in the way that it had a both complete AC and DC equipment, previous locomotives only having a complete AC equipment and a small DC equipment, limiting their power under 1.5 kV.With a full AC and DC equipment, BB20005 developed nearly 85% of its power under 1.5 kV, which was a great achievement at that time, knowing that only 2 years before BB20004 developed only 45% of its power under 1.5 kV.
The prototype helped to develop the bogies of the 2 'BB Jacquemin [fr]' series: the BB25150 series which had bogies for 130 km/h (81 mph) and were lower geared (to pull heavier freight trains) and the BB25200 series which had bogies for 160 km/h (99 mph) and were higher geared (for lighter passenger trains and to operate in push-pull mode).
