BCM Second Class motor carriages were converted from _BC_ Second Class car/vans.
A description of the conversion is in the ACM_ car history.
BCM's were placed into service between 1919 and 1921. There were only twenty seven cars, numbered 1 - 27.
These cars were recoded to _M__ between 1921 and 1924. BCM 1 - 27 became M 128 - 154.
Some of the BCM cars were significant, either for discrepancies in records or enlightenment of past events: