Page 1 of 1

What colour for signal disc....?

Posted: Tue Jan 21, 2020 1:00 pm
by nutford
Below is a pic of a MacKenzie & Holland ground signal, at Ripon.

The map extract below shows where the signal was - I have marked the main running lines in red/green for clarity, the blue square is the signal.

This signal was at the end of the short bay, and physically linked to a point which either gave access to the main line, OR to a series of further sidings. It had only one disc. That point could not actually be set AGAINST a train in the bay - just determine which potential route was possible. I have 3 options in my head:

1) The disc was red and referred to the link to the other sidings - because a train was never allowed to leave straight on to the mainline, that access was only permitted to reverse into the bay. (There was an access back to the mainline through the other sidings route). The problem with that (even if it made sense) is if there were more than one or two cattle vans at the cattle dock, nothing could get out of the bay platform by that route - they fouled the point. Anything in the bay was trapped unless it could be taken out onto the main line.
2) The disc was yellow, and referred to one direction or the other - not sure which.
3) The disk was red, and set specifically for the intended movement of the train in the bay. Or perhaps linked to a viable route being set via a combination of that point it is linked to and the two potential subsequent point settings.

The third I think seems most sense - but this is NER signalling we're talking about, and have already learnt that 'makes more sense' is not necessarily the way it worked ;-)

Any suggestions guys?

Re: What colour for signal disc....?

Posted: Tue Jan 21, 2020 11:40 pm
by Mickey
I am guessing that it is a red face ground signal?. I don't know when yellow face ground disc signals were introduced but a general observation was that during the B.R. era of the 1960s & 1970s they weren't that numerous about on the railways and taking the GN main line from Kings Cross to Hitchin in particular I recall one being on the ground coming off the stops in Kings Cross passenger loco and heading into the re-fueling point beside the Down slow line just before the mouth of Gasworks tunnel before being replaced by a red face disc sometime around 1970/71 also I believe one was in the Up sidings at Langley Junction leading onto a headshunt and another one (or two?) may have been around Hitchin at either Hitchin Yard or Cambridge Junction?.

Re: What colour for signal disc....?

Posted: Wed Jan 22, 2020 12:21 am
by nutford
Mickey wrote: Tue Jan 21, 2020 11:40 pm I am guessing that it is a red face ground signal?. I don't know when yellow face ground disc signals were introduced but a general observation was that during the B.R. era of the 1960s & 1970s they weren't that numerous
The LNER certainly did have some yellow ground signals (of later type), and there is a pic of another similar signal at Ripon where the disc is certainly not red - it looks white in the B&W pic but is presumably yellow. Though that signal is old the date of the photo is less so, and the jury is out as to whether it was always yellow....

The one in this pic looks red - but could just be filthy. But my feeling is it IS red, but I am guessing at both that and its precise function.

I am trying to model Ripon with working signals - but my knowledge of these things is not much, and there seems to be a lot of oddities to say the least!

Re: What colour for signal disc....?

Posted: Wed Jan 22, 2020 1:13 am
by John Palmer
Presumably the signal under discussion is 28, as shown in your thread on 'bothways signals'. I suggest 28 is released by 27 points and reads over the connection from Dock to Down Main. It will originally have been a red disc, and for whatever reason may never have received a coat of yellow paint, even though there would be no reason in principle why it could not be passed at danger in the case of a movement into the Timber Dock. So far as the points in advance of 27 are concerned, I would expect 24 points reverse to lock 27 and vice versa. 9 points were probably not interlocked with 27 points, given that they lie in advance of the Down Starting signal (41, up to which I take 28 to read). Operational considerations may make it desirable to have both 9 points and 27 points concurrently reversed; for example this would permit a Down goods to be recessed via 9 points whilst a movement simultaneously exits the dock over 27 points preliminary to a movement to the Up side.

The wooden ramp and bridge just ahead of 28 is probably a walkway over the detection slides that 'prove' the position of the tongues on 27 points.

Re: What colour for signal disc....?

Posted: Wed Jan 22, 2020 9:45 am
by nutford
John Palmer wrote: Wed Jan 22, 2020 1:13 am Presumably the signal under discussion is 28, as shown in your thread on 'bothways signals'. I suggest 28 is released by 27 points and reads over the connection from Dock to Down Main. It will originally have been a red disc, and for whatever reason may never have received a coat of yellow paint, even though there would be no reason in principle why it could not be passed at danger in the case of a movement into the Timber Dock. So The wooden ramp and bridge just ahead of 28 is probably a walkway over the detection slides that 'prove' the position of the tongues on 27 points.
Yes John, 28 it is! I do have a problem with your theory though. That's because the timber dock route isn't a dead-end siding - it does go into the timber dock but also up to other loop sidings which have another (two in fact) routes back to the main line. So the cattle dock can be accessed from the main line further up - in fact it would be, since the bay isn't long enough to get much into it from there. So if that signal could be passed at danger, there seems no way of safely allowing a train to reverse into the cattle dock if there is one in the bay - well not by signals anyway.
(Pic below demonstrates).

If a loco was in the bay, with intent to go into the timber dock, it could potentially hit a train reversing into the cattle dock from the mainline if that signal could be passed at red...

I take the point that the fact the signal can be passed doesn't mean it is safe to pass - but If two locos were on that same set of sidings shunting stuff about - and a quick glance at the track plan shows what a mess it is, with access to the timber dock requiring the cattle dock to be cleared first - it could be difficult to control by direct human instructions unless everyone involved was 100% certain what everyone else was doing and when. Of course that situation may have rarely occurred, (two ways of reading that, both true!) except that a passing train, say, dropping off a van into the bay couldn't just wait about for the cattle vans to be moved etc for some other event. And that loco might be going back to the main line - or it might be going into the timber dock or up into the sidings loops.... it wouldn't be obvious, or necessarily a regular event.

So - you still of the same mind?

Re: What colour for signal disc....?

Posted: Wed Jan 22, 2020 1:39 pm
by thesignalman
nutford wrote: Wed Jan 22, 2020 9:45 am Yes John, 28 it is! I do have a problem with your theory though. That's because the timber dock route isn't a dead-end siding - it does go into the timber dock but also up to other loop sidings which have another (two in fact) routes back to the main line. So the cattle dock can be accessed from the main line further up - in fact it would be, since the bay isn't long enough to get much into it from there. So if that signal could be passed at danger, there seems no way of safely allowing a train to reverse into the cattle dock if there is one in the bay - well not by signals anyway.
(Pic below demonstrates).

If a loco was in the bay, with intent to go into the timber dock, it could potentially hit a train reversing into the cattle dock from the mainline if that signal could be passed at red...

I take the point that the fact the signal can be passed doesn't mean it is safe to pass - but If two locos were on that same set of sidings shunting stuff about - and a quick glance at the track plan shows what a mess it is, with access to the timber dock requiring the cattle dock to be cleared first - it could be difficult to control by direct human instructions unless everyone involved was 100% certain what everyone else was doing and when. Of course that situation may have rarely occurred, (two ways of reading that, both true!) except that a passing train, say, dropping off a van into the bay couldn't just wait about for the cattle vans to be moved etc for some other event. And that loco might be going back to the main line - or it might be going into the timber dock or up into the sidings loops.... it wouldn't be obvious, or necessarily a regular event.

So - you still of the same mind?
I agree with John. Whether or not the route to the main line is rarely used, to BoT requirements are that a signal is provided to protect the move. It would certainly have originally been red, though may have become yellow in later years.

As a red signal it should only be passed with permission. Yellow shunt signals are a bit different - they can be passed if the points are set for the straight route.

And don't worry about engines colliding in yards. Shunt signals do not indicate it is safe to proceed. They only indicate that the line is clear as far as can be seen. The sidings would be under the control of the shunter and drivers would obey their handsignals and instructions.

Another John

Re: What colour for signal disc....?

Posted: Wed Jan 22, 2020 3:36 pm
by nutford
What's better than one John?
Two obviously :-)

Thanks guys. Trouble with this signalling is you start off just wanting the odd signal... then all of a sudden you want the RIGHT signals, doing the RIGHT things. And even want to know WHY lol!

The whole layout will be computerised - so all I need now is a macro to have the signalman come out on the veranda and tell the driver when to go ;-)

Anyway - that's Ripon sussed, just Melmerby and Tanfield to sort now. Melmerby - double track main line, with junction to second main line, plus a branch line and two goods yards. Oh yes, and no proper signal plan, just a small number of pics spread over 50 years with barely two of the same signals in any of them.

No probs there shouldn't think......

Re: What colour for signal disc....?

Posted: Wed Jan 22, 2020 9:31 pm
by StevieG
I agree with the John's nutford, noting that, as alluded to, a shunter (or if none, a train guard) member of staff would be controlling the shunting movements (as long as any signals needing to be cleared, were 'Off').
So perhaps your 'macro' would need to be someone on the ground popping up rather than an on-veranda signalman !

Re: What colour for signal disc....?

Posted: Wed Jan 22, 2020 10:54 pm
by nutford
StevieG wrote: Wed Jan 22, 2020 9:31 pm I agree with the John's nutford, noting that, as alluded to, a shunter (or if none, a train guard) member of staff would be controlling the shunting movements (as long as any signals needing to be cleared, were 'Off').
So perhaps your 'macro' would need to be someone on the ground popping up rather than an on-veranda signalman !
That's Macro 2. Macro 1 is the signalman wondering where the heck 'man on ground' is and why isn't he shifting that loco out of the bay ;-)

Re: What colour for signal disc....?

Posted: Thu Jan 23, 2020 12:22 am
by StevieG
:D

Re: What colour for signal disc....?

Posted: Thu Jan 23, 2020 11:07 am
by thesignalman
StevieG wrote: Wed Jan 22, 2020 9:31 pmSo perhaps your 'macro' would need to be someone on the ground popping up rather than an on-veranda signalman !
That would be a "Jack-not-in-the-box" then?

More seriously, we are of course talking about the "proper" way to do things. In reality, almost everywhere had is own unofficial variations to make life easier. I have worked at a few places where it was considered perfectly OK to pass red shunt signals without any authority whatsoever. It had always been done that way, and forever was to be. Until something went wrong, of course . . .

(At one of those places, the shunt signals were yellow on the diagram and red outside - owing to lack of yellow ones at the time of resignalling).

So we don't really know how Ripon was really worked, we can only say how it should have been worked.

John No2

Re: What colour for signal disc....?

Posted: Thu Jan 23, 2020 9:54 pm
by nutford
'So we don't really know how Ripon was really worked, we can only say how it should have been worked.'

Indeed. And to try to reconcile that with what evidence we can find.

Part of me wished we could actually know these things, as future modellers will be able to look online at old google map pics etc and see exactly what buildings were where, what the rules were, etc etc.

But... what's the fun in that... ;-)

The harder the quest for the solutions the more satisfying when you find them!

Re: What colour for signal disc....?

Posted: Fri Jan 24, 2020 1:32 am
by StevieG
Think you've crystallised the realistic answer there John.