The 'Z' group of steel welded cars were introduced in the late 1950's in a railway rehabilitation programme.
Between 1957 and 1960 twelve cars entered service: BZ 1 - 12.
During the construction of BZ 13, the partially completed shell caught fire. The shell was rebuilt but in the ensuing time, there were BZ car conversion to standard guage ( SG ) services. The car entered service as VFK_ 5.
For SG service, four BZ cars were reclassed VFK 1 - 4 in 1961.
In the 1980's, the renumbering scheme placed the VFK numbers into the '270' range: VFK 1 became VFK 271, etc.
In the early 1990's all the standard guage cars were replaced to broad gauge; replaced by the XPT train sets.