Tyler Block Apparatus

During my childhood and early 'teens I had the equivalent of a 'mis-spent youth' hanging around many of the signal boxes worked by my grandad. A perfect 'gricer' upbringing eh?

Of course I didn't just sit there and watch either did I? I worked all those trains as they came and went, 'setting the road' pulling 'off' the signals and handling the telegraph instruments.

So pieces of kit like the Tyler 'Absolute Block' apparatus are very familiar to me. This is the piece of equipment that 'reserves' the track between two signal boxes for a particular train. Basically if it's used correctly it's theoretically impossible for two trains to be on the same line at the same time. Normally the line is considered 'blocked' but when a train needs to move the receiving signal box sets the equipment to 'line clear' and then the dispatching signal box sets it to 'train on line'.

Foolproof. Theoretically, that is.

I first learned something about electric shocks using this bit of gear, or rather the telegraph key that goes with it. When 'offering' a train at Hopetown Junction at Darlington with my left hand on a steel lever ready to pull my right hand slipped off the ebony key and onto the brass contact underneath. It was then I discovered that 90 volts DC packs quite a punch.