Split shifts sometimes called spreadovers seem to be used in the bus industry to boost the service in peak periods. The entire shift exceeds 12 hours but drivers are often only drive 8 to 9 hours. Is this a good idea for the rail industry ?
A split shift is where you might work 6 am to 10 am then have a few hours off and work 3 pm to 7 pm or something like that.
It is common in other industries eg catering. However the same safety issues don't apply. - though they might do in hospitals where some doctors do work these sort of hours!
I'm sure it's popular from a business point of view but rules are there that you are paid from the start of a turn to the end of one.