Railwaymen knew these heavy metal discs as 'tablets' and in signal boxes they were locked into a machine known as the "Tyler Patent Tablet Apparatus". They were the critical link in a safety system to ensure that two trains couldn't collide head on when using a length of single track between stations. The system worked by having a tablet machine in the signal boxes at each end of a section of track - in this case between Kirkby Stephen and Warcop. You could only ever have one tablet out of the pair of machines at any time. The driver carried it with him in the cab of the locomotive and it was his guarantee that he wouldn't meet a train coming the other way, a disaster known to American railwaymen as a 'cornfield meet'!
'Tablets' were handed between signalman and driver in a black leather pouch attached to a white hoop, and you often see these in collections of memorabilia too. There was quite a knack to hook it over the arm of a driver high up on the footplate of a passing locomotive at night, and if you missed and he dropped it there would be a great deal of cussing from the footplate as the brakes were slammed on and the fireman had to clamber down and retrieve the dropped item from the trackside. But there was no question of carrying on without that all important tablet in the cab.
Do you have a tablet from any of the sections of the single lines on which they were used around Kirkby Stephen, or east of 'Barney'? If so we would love to hear from you.
When I lived back in the Far North there was the Haltwhistle to Alston branch line, closed in 1974. It was a single track line that had a similar tablet system. I lived near Lambley, the station half way along where the tablet was exchanged.
ReplyDeleteStrangely enough, when the change from stean to DMU's was made, this tablet system was discontinued.
Now the line is narrow guage and run by volunteers but only from Alston to some miles short of Slaggyford.
I guess that was because they moved over to a method of operating where only one train was ever allowed up the branch at any one time Norman - in steam days it used to be called 'One Engine in Steam'
ReplyDeleteI remember taking that DMU up from Haltwhistle to Alston in 1966. It was a bumpy ride and I think a 5mph limit over the viaduct at Lambley which looked well 'out of true' by then.