Some of the tablets are well worn bakelite and others are fairly new plastic ones.
Shame. I've got a couple of the classic heavy old ones in brass mounted on the wall. They get shone up with the Brasso about once a year. They came from old Southern lines in Devon (the GWR lines all used aluminium Key Tokens, and I've some of those as well).
So with a Pilotman on board the train it looks like the signal line working system was up the creek that day. It could be a tablet machine failure or more likely a cable fault between the two signal boxes.
On the old Taunton branches the most common reason was neither (which would have been embarrassing to the S&T lineman), but loss of the token while running. The GWR token catchers, a scissors-like arrangement mounted on the tender front, allowed exchanges at about 30mph. Slight misalignment and the token would fly off in a spectacular parabola, generally into a drainage ditch or middle of a blackberry bush. Brakes on, if the signalman hadn't seen it go it would take too long to get the S&T lineman down to reset the token instruments, so the stationmaster donned the piilotman armband and spent the rest of the day going up and down.
Tokens being fumbled in a hand exchange and falling under the train wheels were a further amusement
David L Smith. in his books about the G&SW, had the best story (as always). Temporary single line working past some major works. Novice fireman. Driver picks up the big hoop to show how to do it, then tells his young colleague that "at the far end a man will stand with something to catch it, just hang the hoop over it as we pass slowly by". Unfortunately, as they approached, the surveyor is just setting up his theodolite alongside the line ....
