A Signalling Sighting Conundrum

[Adam]

The club's EM tailchaster, South Juction, has never yet been fully signalled, but it's been a long-term aspiration for at at least non-working signals to be installed. Time permitting, we may even get around to making some at least operate. Anyway, I appreciate that the up line (left hand as shown in the picture) appraching the junction really requires a stop signal (ignore the backet in the background, this refers to the other line). As you can also see - hopefully - sighting of this would be a nightmare with both the cutting and bridge (shortly after a tunnel) obscuring the view.

 

 

My guess is that either/or a tall co-acting signal and a banner repeater before the bridge at a much lower level - and so visible on exiting the tunnel - would be provided. Is that right/likely? Or have I got this totally wrong?

 

Any advice gratefully received>

 

Adam

[Edwin_m]

It probably depends on region/company and era.

 

I presume you'd like the signal close up to the junction near the end of the retaining wall. I'm not sure even the high signal would be easily visible when leaving the tunnel unless it was positively stratospheric. Can you give us a driver's eye view by placing the camera in the tunnel mouth?

 

I think a banner on the approach to the bridge would work.

[Adam]

Thanks Edwin

 

Note the Midland Railway signal box in the background Post war on the LMS or BR(M) is the era sorry, I should have stated that.

 

I'm currently 70 or so miles away from the layout and unlikely to actually set eyes on it for a week or two, and I admit that I've only thought of it now while going through the pictures. Had I thought about it a little bit more, a co-acting signal would be unlikely for exactly the reason you suggest: I'm reasonably certain that the driver wouldn't be able to see end of the retaining wall from the tunnel exit.

 

So, theory 2: a banner repeater immediately before the bridge and a stop signal - possibly bracketed out for improved visibility? - more or less where you suggest. Opinions? Suppressed mirth?

 

Adam

[big jim]

i'd say a banner before or on the bridge then the stop signal beyond it where the retaining wall ends

 

as a possible prototype example of a poorly sited signal protecting a junction here's a piccie i took while i road refreshed the liverpool dock branch with fastline, the 37 is sat on the exit to the curved tunnel (picow No1 i seem to recall, beast 66606 will no doubt correct me if i'm wrong) and you can make out just how close the signal is to it, this one however has no banner repeator and you dont see the signal until you are virtually exiting the tunnel, also prior to resignalling the signal previous to this one was a reflective fixed distant so you had to creep up to it regardless, it now however has a "working" colour light led signal before it

 

[Edwin_m]

I'll let someone else comment on whether a banner repeater would be appropriate for an ex-Midland route in the BR steam era. 'fraid my eyesight isn't good enough to ID the signal box at that distance.

[Tim V]

Why not put in an outer home?

[beast66606]

Why not put in an outer home?

 

It depends on the traffic requirements as to whether an outer home would be provided, I reckon a small straight post signal, as drawn, would suffice

 

[Adam]

Thanks Jim, Edwin and Tim

 

My knowledge of signalling is fairly basic, hence the question. Having acquainted myself with what an outer home actually is, this is what I thought it should be, so I must have understood at least some of the theory I've picked up, and I can't see why not. A couple of supplementary questions then:

 

1. Would these be interchangable?

2. Assuming the answer to 1. is yes, was there a regional preference on the Midland one way or the other?

 

With the parts I have in hand from the last signal I built, the stop signal will be a Midland article either in original lower quadrant form (if I have enough bits), or modernised with an upper quadrant arm if not. The one in the cutting will have to be on some sort of bracket rather than hung off the bridge I guess? Thanks again.

 

Adam

[Adam]

Thanks Dave (our replies crossed). With the relative sharpness of the curve, the line speed should not (operator discipline permitting...) be all that high so a repeater would be less likely?

 

I'm quite happy to build whatever is required, of course, and the single post has the advantage that I have the bits in stock.

 

Adam

[beast66606]

With the relative sharpness of the curve, the line speed should not (operator discipline permitting...) be all that high so a repeater would be less likely?

 

Hi Adam,

 

Thats correct - I'v assumed you don't have any facing connections which would require additional dolls of course.

[The Stationmaster]

Clearly of Midland Railway origin (unless it's got the wrong signals already in place) so look for what they would have done - any reference pictures of similar sites you might have or can find. But in the LMS era I would think the provision of a banner repeater the most likely judging from similar situations elsewhere.

[Adam]

Thanks again Dave, you're correct, there are no facing points needing an extra doll.

 

Clearly of Midland Railway origin (unless it's got the wrong signals already in place) so look for what they would have done - any reference pictures of similar sites you might have or can find. But in the LMS era I would think the provision of a banner repeater the most likely judging from similar situations elsewhere.

 

And thank you Mike. It seems I might have to visit MSE at Warley after all.

 

I'm not convinced about the lattice bracket in the background I must admit. I think it does the right thing, for the supposed layout of the rest of the unmodelled world, [Edit: thinking about it, it reflects the major divergence in the fiddle yard accurately!] but it looks like no LMS or Midland signal I can find pictures of. I think these are D&S etches assembled a very long time ago - it may well have been all that was available at the time. Given Danny Pinnock's predilections, an LNER constituent is likely. The Midland box post-dates the signals and the layout was designed to be somewhat 'generic'. Unfortunately, I have this strange notion that it would be nice if the box and signals matched!

 

Thanks again

 

Adam

[The Stationmaster]

Thanks again Dave, you're correct, there are no facing points needing an extra doll.

 

 

 

And thank you Mike. It seems I might have to visit MSE at Warley after all.

 

I'm not convinced about the lattice bracket in the background I must admit. I think it does the right thing, for the supposed layout of the rest of the unmodelled world, but it looks like no LMS or Midland signal I can find pictures of. I think these are D&S etches assembled a very long time ago - it may well have been all that was available at the time. Given Danny Pinnock's predilections, an LNER constituent is likely. The Midland box post-dates the signals and the layout was designed to be somewhat 'generic'. Unfortunately, I have this strange notion that it would be nice if the box and signals matched!

 

Thanks again

 

Adam

 

I think (based on what I saw, and could ever find out about them) that all the signalling components which appeared from D&S were based on LNER/its constituents. MickNich might know more possibly?

 

 

[TheSignalEngineer]

A sketch of the junction layout would be useful, but from the picture a few options could be possible. Also the area (Midland/LMS/LMR?) and period, as rules and principles changed over time, often as a result of accidents.

With absolute block signalling an outer home would be 5.28 metres from the fouling point of the junction at 4mm scale. Not really practical in the modelling world so some compromise is necessary. Firstly is it necessary for trains to pull right up to a signal at the junction to stop? If it is, an outer home could be provided, albeit at a non scale distance from the signal at the junction. The train would come virtually to a stand at the outer home before the signal was cleared, and then would draw up slowly to the junction signal. Alternatively a banner signal could be positioned on a wall bracket just before the bridge. In both cases the signal at the junction could be a straight post with the arm at say, 60mm to 80mm above rail level. If drawing right up to the junction was not essential another option would be to put the signal protecting it on a wall bracket at the bridge. Given a bit of modelling license, this could be operated like an outer home without providing an inner home. The issue could hinge on what conflicting moves are to take place across the junction when the train is approaching.

[beast66606]

I'm not sure why it is assumed a banner would be provided ? - this was nowhere near always the case, especially if the line speed was low - as it is here.

 

The outer home is typically 440yds (assuming semaphore signals) from the inner and was provided for acceptance purposes, it would not be permissible to drop a train from the outer to the inner if another train was signalled in a conflicting route, no matter how slow the train was running, as Adam has already said there are no facing points there are no alternate routes which could be set to provide an alternate overlap in front of the inner, so it comes down to traffic requirements. If the previous box was only a matter of a few hundred yards away it is likely an outer would not be provided, even if the previous box was a distance away its still not a certainty - a major (ex LNW) junction near me with a 4-track main line, a double track branch and a single track branch did not get outer homes until the 1970s, despite the LMR altering the signals in the early 1950s, and it didn't have any banners despite both branches approaching the junction on sharp curves.

[Adam]

A sketch of the junction layout would be useful, but from the picture a few options could be possible. Also the area (Midland/LMS/LMR?) and period, as rules and principles changed over time, often as a result of accidents.

With absolute block signalling an outer home would be 5.28 metres from the fouling point of the junction at 4mm scale. Not really practical in the modelling world so some compromise is necessary. Firstly is it necessary for trains to pull right up to a signal at the junction to stop? If it is, an outer home could be provided, albeit at a non scale distance from the signal at the junction. The train would come virtually to a stand at the outer home before the signal was cleared, and then would draw up slowly to the junction signal. Alternatively a banner signal could be positioned on a wall bracket just before the bridge. In both cases the signal at the junction could be a straight post with the arm at say, 60mm to 80mm above rail level. If drawing right up to the junction was not essential another option would be to put the signal protecting it on a wall bracket at the bridge. Given a bit of modelling license, this could be operated like an outer home without providing an inner home. The issue could hinge on what conflicting moves are to take place across the junction when the train is approaching.

 

Thanks. I don't have a sketch of the junction layout to hand - though I can certainly manage this when I next get near my camera lead - but I do have a picture taken from the opposite direction which might help (see below). For the purposes of exhibition running we would rather trains ran up to the junction stop signal.

 

My preference at this stage - if anything has to be there at all of course - based on the advice received above (and from yourself) would be a banner bracketed from the wall in front of the bridge. The cutting wasn't built with provision for a signal post - though one could be squeezed into so a wall bracket makes sense, but not having to provide one at all would be easier still!

 

Hypothetically, and at least partly out of curiosity, would I be correct in thinking that such a bracket would be very like one attached to a signal post? All the pictures I've been able to locate in a quick search show modern installations, usually in stations which are obviously a bit different.

 

 

Adam

[beast66606]

For the purposes of exhibition running we would rather trains ran up to the junction stop signal.

 

See my comments re acceptance to conflicting route, the junction would have to be set "to the left" for a train to drop to the signal.

 

My preference at this stage - if anything has to be there at all of course - based on the advice received above (and from yourself) would be a banner bracketed from the wall in front of the bridge. The cutting wasn't built with provision for a signal post - though one could be squeezed into so a wall bracket makes sense, but not having to provide one at all would be easier still!

 

Your choice - I don't believe a banner is required but you should provide a signal at least.

 

Hypothetically, and at least partly out of curiosity, would I be correct in thinking that such a bracket would be very like one attached to a signal post? All the pictures I've been able to locate in a quick search show modern installations, usually in stations which are obviously a bit different.

 

Unlikely, it would probably be a bespoke build, given the difficult location.

[Southernman46]

Stop signal at the junction clearing point as show in one of the photos - with an unseen distant somewhere on the approach to the tunnel. This would indicate whether the stop signal protecting the junction was "on" or "off".

[TheSignalEngineer]

A bracket from the wall would often look similar to that on a junction signal. The flitches were sometimes effectively buried into the wall, there are still instances visible around the system where stubs of these have been burnt off. The ladder would be usually fixed to the wall.

There have been comments about the lattice signal on the layout. I know these were used on the LNER, but straight posts at least were widely used by the LMS, and I also have a drawing of a junction signal similar to the one one the layout from the LSWR.

 

Charles

[Adam]

Thanks again, that's very helpful. A single, simple post with a single arm will be provided forthwith. Once that's done, and I'm next in Somerset, I'll reassess the situation and provide an update. I will also do something about that erroneous lattice... *

 

Adam

 

* The LMS did use Lattice posts, I know, but they weren't like the ones we have at present!

[beast66606]

There have been comments about the lattice signal on the layout. I know these were used on the LNER, but straight posts at least were widely used by the LMS, and I also have a drawing of a junction signal similar to the one one the layout from the LSWR.

 

The LMS used lattice main stems, on brackets, for quite a while, and of course completely lattice signals were mandatory above a certain height

[Trainshed Terry]

It depends on the traffic requirements as to whether an outer home would be provided, I reckon a small straight post signal, as drawn, would suffice

 

 

And I would be inclined to place a banner repeater at the start of the curve so that the loco crew have an advance warning of the position of the home signal shown in the photo.

 

Terry

[cb900f]

If you were to put the signal protecting it on a wall bracket at the bridge, you could always paint a white square on the bridge behind the signal to act as a sighting board to aid the 4mm driver.

How about a 2 aspect colour light on the floor instead ?

Although it is a good idea to give the driver as good a sighting as possible, in reality this is not always the case as I am sure everyone is aware of. At the end of the day the driver's route knowledge is what counts.

 

Pete

[Geoff Endacott]

Banner repeaters are seldom modelled so why not put one in because it would look interesting?

 

Geoff Endacott

[Captain Kernow]

While I was reading down through the thread, I was thinking that an Outer Home would be required, to enable you to drop down to the junction, then I found Dave's comments, which reinforced my own views.

 

There was a 'bracket' type signal mounted on a brick retaining wall coming off the Lambourn branch at Newbury, if you can find a photo of it - purely in terms of a 'prototype for everything'..

 

If you have the main junction home signal where Dave sketched it in on the photo, and given 'modellers licence/layout compression', perhaps you could have an outer home mounted on a bracket coming out of the retaining wall between the tunnel and bridge, possibly with a small/bespoke arm with a centre pivot?

 

Operation of the layout could thus demonstrate junction acceptance - ie. the train stopping at the Outer Home when a conflicting route was set ahead of it at the junction.

 

Drivers would be assumed to have a full and comprehensive route knowledge and would know that if the distant signal for these homes was 'on', then he should not expect any of them to be clear until he saw them, hence a cautious approach would be called for (slow linespeed notwithstanding).