These vans were in 1961. The construction started as _BB_ group until October. These BB vans, numbered 23 to 118 were issued with plain bearing bogies.
The first van issued with roller bearings was BF 119 on the 5th Oct 1961. Some of the earlier BB vans were also modified to BF during October. These were BB 22, 35, 41, 45, 54, 57, 75, 85, 88, 93 and 105.
One month later BF 22 was reclassed to BMF_ 1. The remaining BF vans were reclassed to BLF_ during the rest of 1961 and early 1962.
Vans numbered 120 and onwards were issued to service as BLF.