Train waiting indicators

[uax6]

A friend has acquired a train waiting indicator unit, and has installed in in his signalbox for his 7 1/4" railway. The indicator works by treadle, and is sited on the approach to a signal. The indicator consists of a standard needle dial that swings to train waiting when the treadle operates, and also rings a bell until a silence button is depressed. The indicator works when the signal is on, and when you pull off, the indicator resets.

 

My question is this:

Would the signal post have some sort of symbol on it to show the traincrew that the signalman is aware of the train sat there?

Would the indication be good enough to make the signal rule 55 exempt?

 

Andy G

[david.hill64]

Semaphore signals had a white diamond on the post to show that the line had track circuits and therefore the signalman was aware that the train was occupying that block. I leave it to others to write chapter and verse about Rule 55, but I think that the short answer was that it was not necessary (in most circumstances?) to report to the bobby when stopped at that signal. An alternative was the presence of a remote reporting device, the presence of which was denoted by a different plate - a sort of a D shape.

 

We need someone more competent than I in UK signalling practice to answer, but I I suspect that all lines in multiple aspect colour light areas are equipped with vacancy detection (track circuits or axle counters).

[Oldddudders]

Semaphore signals had a white diamond on the post to show that the line had track circuits and therefore the signalman was aware that the train was occupying that block. I leave it to others to write chapter and verse about Rule 55, but I think that the short answer was that it was not necessary (in most circumstances?) to report to the bobby when stopped at that signal. An alternative was the presence of a remote reporting device, the presence of which was denoted by a different plate - a sort of a D shape.

 

We need someone more competent than I in UK signalling practice to answer, but I I suspect that all lines in multiple aspect colour light areas are equipped with vacancy detection (track circuits or axle counters).

 

Yes, a "fireman's plunger" was often used for remote reporting at such signals. 

 

Stationmaster is probably among the best people to comment, but MAS and track circuitry generally go together. Even the odd colour light signal in absolute block areas, say an Intermediate Block Signal, would almost certainly have a berth track circuit. 

[31A]

The "Fireman's Plunger" D-shaped sign is an indication that the fireman needs to do something (press the plunger) whereas the white diamond indicates that the loco crew don't need to do anything (i.e. they don't need to carry out Rule 55), so I would have thought the white diamond would be more appropriate.  Having said that, the device you describe sounds a bit like an 'annunciator' which gives an indication to the signalman of a train's approach - as far as I know, there is no lineside indication of these.

[The Stationmaster]

The Rule 55 exemption (from most of it although with some bits modified and still applying) existed at signals where there was something to remind the Signalman of the presence of a train at the signal concerned.  Most commonly this was done by means of a track circuit but in some cases - usually associated with particular designs of block signalling equipment - a treadle was used instead although its primary purpose was part of the block system.  One interesting exception from the use of the diamond symbol was at an Intermediate Block Home Signal which although it had berth track circuit in rear in many cases didn't carry a diamond plate and most eventually carried a different plate (vertical black band on a white background) to indicate that it was an I.B, Home - the reason for this was that different Rules applied at an I.B. Home.  Incidentally at one time some I.B. Homes had 'D' plates on some Regions.

 

Generally, as Ian has said some track circuiting was installed along with colour light signals - technically only with colour light stop signals but not necessarily always including a berth track circuit (I.e. in rear of the signal) in the case of isolated replacements for semaphores.  However in MAS (Multiple Aspect Signalling) and full Track Circuit Block working continuous track circuits (or nowadays detection by means of electronic axle counters) are essential.  However the interesting thing is that traditional use of diamond plates indicating Rule 55 exemption in such areas changed in the 1960s - up to approximately the mid '60s it was usual practice to provide diamond plates on colour light stop signal in TCB areas but that changed and the practice ceased, including removal of diamond plates from existing signals.  The reason for this was to encourage traincrews to quickly contact the Signalman in the event of being brought to a stand at a signal - odd when you think about it but with the panel boxes controlling large areas trains could be overlooked even though they were obviously protected by signals.

 

The other thing to bear in mind is that introduction of Track Circuit Block didn't necessarily mean that colour light signals would be, or needed to be, installed - it's the the track circuits and signalling method that matter, not the type of signal so there were instances of TCB being used with semaphores on some Regions.

 

Track circuits were also increasingly installed over the years in connection with traditional Absolute Block working and the adoption of Welwyn Control required the provision of a berth track circuit in rear of the outermost Home Signal.  This track circuit is interlinked with the block in order - in essence - to prevent a second train being accepted if the first train has not occupied that track circuit but it has the by-product of also providing an indication that a train is standing at the signal ( so thus has some similarities with the use of a treadle in Sykes Lock & Block).

[Grovenor]

A bit more on block controls here, http://www.norgrove.me.uk/signalli-LMS.htm

Regards

[TheSignalEngineer]

There is a 'Rail Contact' shown on this box diagram for Ely Dock Junction. Look to the bottom right corner 100 yards before reaching signal 81. 

The symbol is that for a train operated treadle, a circle with a line to the track.

https://flic.kr/p/fSekQN