Between 1883 and 1887 there were twenty six vehicles placed into service as BD. From 1887 to 1904 a further forty six vehicles were converted to BD from classes _AD_ and ABD_.
The number group was 1 to 68.
About 1895, two BD cars were relegated to excursion traffic and coded to BDH.
In the 1910 recoding the class BD was relettered to _YZ_ with the same numbers retained.
BD cars 43 and 67 became BDH 43 and 67. They were retained for holiday traffic and stored at other times.
In the 1910 recoding they were relettered to YZH_.