On an earlier post someone asked in the comments why we have spares. Yesterday when one of my colleagues was booking on they told the DTSM that they had used an over-the-counter remedy for an ailment. When the DTSM consulted the list of medications its okay for us to use and carry on working it wasn’t listed so they couldn’t legally book the TOp on for their duty.
Fortunately we had one spare available who was able to cover the shift otherwise we’d have had to cancel one of the last trains. That was me.