A Class 47 standing in for a DMU
In slightly more detail.
Vice = instead of (as in Vice-chair etc)
Turn = (or diagram or duty or....) train or consecutive series of trains worked by the same locomotive (and coaches) or multiple unit
Duff = spotter slang for class 47
EH = ETH = Electric Train Heating fitted (the 47s were first built when steam heating was the norm for loco hauled trains - by this time most older coaches had been re-fitted for ETH)