The DRS-6-4 series included road switchers that had a total of six axles, four of which were powered. The three less powerful variants each had a six-cylinder with 660, 750 or 1,000 hp, with only the most powerful variant having a turbocharger. 

SNCF A1AA1A 62030 in September 1983 at Bobigny depot

Didier Duforest

The first variant with 660 hp was manufactured from 1946 and 100 of the 106 locomotives went to the SNCF. They were derived from the four-axle VO-1000 and had a carrying axle in each bogie to reduce the axle load. They were given the designation A1AA1A 62000 and remained in service until 1994. The remaining six went to Morocco.

Sectional drawing of the DRS-6-4-660NA

Didier Duforest

The DRS-6-4-1000 received the same six-cylinder engine as the 660 hp variant, but here it delivered 1,000 hp thanks to a turbocharger. From 1948, 20 of this variant were delivered to Algeria on behalf of France. In 1949 a single naturally aspirated 750 hp locomotive was delivered to Morocco and used to transport phosphate.

The variant with 1,500 hp was powered by an eight-cylinder with turbocharger and was also available from 1946. In the USA it was replaced by the AS-416 in 1950. The DRS-6-4-1500E was manufactured for export until 1952. Ultimately, more than half of a total of 91 DRS-6-4-1500 were sold to Algeria, Morocco and Tunisia.