When I worked for ICOBS one of the overnight sleepers had an extra locomotive put onto the front
An observant tourist, of the American variety, promptly blurted out, "Blimey we've just come down from Inverness and now they are going to put even more muscle at the front"
To that I answered, "No, the driver doesn't know how to the drive they loco they provided, so they managed to find this smaller diesel loco that he does know and that will add about an hour to our journey"
"Oh darn, so why are does each loco have its own driver now?"
"That's because the driver at the front is blind and driver in the other loco knows the route"
"Sounds sensible"
eeeek!