While weโre sticking the boot in to the good old HST, there must be plenty of loco classes that have been called upon to haul one in passenger service. Off the top of my head, I know the following classes have: 20, 25, 31, 33, 37, 43, 45, 47, 50, 57, 58, 59, 67, 86, 89, 91. Any others?
List updated thanks to Wild Boar Fell's post below.
List updated again thanks to Ncarter2 and 45125s posts below.