Railway signalling discussion

Semaphore operation

Current and future British signalling (UK except Northern Ireland)

Re: Semaphore operation

Unread postby Mike Hodgson » Sun May 17, 2015 10:34 am

Sorry for confusion Steve, I have now edited the post. All I am saying is that the locking stops you putting stop signals back in emergency while you've got the distant off. So it's particularly important to put that back as soon as the train as passed it to meet your emergency objective most efficiently, and rules effectively call for all the signals to be put back sequentially to protect the rear of the train as it proceeds.
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Re: Semaphore operation

Unread postby madscientist » Mon May 18, 2015 11:24 pm

thanks for all the contributions
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Re: Semaphore operation

Unread postby Chris Rideout » Tue May 26, 2015 9:01 pm

Regarding sequential locking, it was not necessary to pull off in the direction of travel with Sykes Lock & Block instruments. Each lever was "locked" or "free" according to what had happened previously involving treadles or track circuits. Despite the "anti Sykes brigade" it was one of the best systems I have ever worked and some of the instruments still survive to this day. The only weak spot was the release key. It was needed to release the instruments or signals after a shunt move or loco run round. Most of us will know what happened at Croydon when the signalman forgot a train was there and misused the release key. However such mistakes were few and far between. A tribute to the signalmen who survived 2 world wars and lived to collect their pension of 10 shillings a week.
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