Alsop-en-le-Dale Signalling Diagram: Help Now Needed with Interlocking

[Tortuga]

Since I’m having a slow day on site, I’m going to pick the brains of RMWeb’s collective signalling expertise.

 

Below is a link to the Signalling Railway Society’s diagram of the signalling layout at Alsop-en-le-Dale on the former LNWR Buxton to Ashbourne Line in Derbyshire, which is the basis for my layout.

 

https://www.s-r-s.org.uk/html/lmsr/M154.gif

I’d like to think I’ve got a rough understanding of signalling and railway operation in general terms, but I know that specific locations have their own specific quirks, so I’m seeking clarification with regard to the signalling and operation of this station.

 

1) the diagram indicates levers 5 and 18 through to 22 are spares, but the diagram has no lever number 4: what could be the reason for this?

 

2) do the two short lines to the right of 10 on the up line and to the left of 15 on the down line represent fouling bars?

 

3) would facing point lock 17 lock both 15 and 16? If that is the case, would there be two physical locking mechanisms on the stretcher bars for 15 and 16 with both being operated by a single lever?

 

4) since points 8 and 11 and points 14 and 15 are effectively crossovers, is there any reason why they would be operated by separate levers?

 

5) discs 6 and 7 presumably govern shunting movements on the down line and I’m guessing one is for movements into the siding while the other is along the down line itself, but which is for which?

 

6) ground signals 12 and 13 have a ‘Y’ under them; what does this signify? (From photos, neither appears to be a disc signal in the same way as 6 and 7). Also, what movements would they govern?

 

7) finally (for now!) how would trains arriving from either direction, drop off or collect wagons from the goods yard? I know there were no special rules regarding the yard being served by trains travelling in one direction only, but the loop formed by points 8, 11, 14 and 15 isn’t huge and the blind siding doesn’t look to have been long enough to serve as a headshunt. Would the loop formed by the up and down lines have been used to run around goods trains?

 

Sorry about all those questions - there didn’t seem to be so many when I was pondering them in my head!

 

Thanks for the help in advance!

 

Nik

 

Edited June 7, 2021 by Tortuga

[Poor Old Bruce]

I have got a "403 forbidden". Apparently I do not have permission to access the link.

[Flying Pig]

3 minutes ago, Poor Old Bruce said:

I have got a "403 forbidden". Apparently I do not have permission to access the link.

 

This might work - Alsop en le Dale is on the LMS page: https://www.s-r-s.org.uk/drawings.php

 

The 1922 OS map shows how short the loop and trap were.  I'm guessing the 'Y's indicate yellow shunting signals, which would be interesting as the diagram seems to show them as LNWR types.  Stacked discs are read left to right from top to bottom.

[bécasse]

21 minutes ago, Flying Pig said:

I'm guessing the 'Y's indicate yellow shunting signals, which would be interesting as the diagram seems to show them as LNWR types.

Diagrams my no means always indicate the type of shunting signal on the ground, but anyway yellow versions of the LNWR type existed from c1930.

[RailWest]

3 hours ago, Tortuga said:

Since I’m having a slow day on site, I’m going to pick the brains of RMWeb’s collective signalling expertise.

 

Below is a link to the Signalling Railway Society’s diagram of the signalling layout at Alsop-en-le-Dale on the former LNWR Buxton to Ashbourne Line in Derbyshire, which is the basis for my layout.

 

https://www.s-r-s.org.uk/html/lmsr/M154.gif

I’d like to think I’ve got a rough understanding of signalling and railway operation in general terms, but I know that specific locations have their own specific quirks, so I’m seeking clarification with regard to the signalling and operation of this station.

 

1) the diagram indicates levers 5 and 18 through to 22 are spares, but the diagram has no lever number 4: what could be the reason for this?

 

2) do the two short lines to the right of 10 on the up line and to the left of 15 on the down line represent fouling bars?

 

3) would facing point lock 17 lock both 15 and 16? If that is the case, would there be two physical locking mechanisms on the stretcher bars for 15 and 16 with both being operated by a single lever?

 

4) since points 8 and 11 and points 14 and 15 are effectively crossovers, is there any reason why they would be operated by separate levers?

 

5) discs 6 and 7 presumably govern shunting movements on the down line and I’m guessing one is for movements into the siding while the other is along the down line itself, but which is for which?

 

6) ground signals 12 and 13 have a ‘Y’ under them; what does this signify? (From photos, neither appears to be a disc signal in the same way as 6 and 7). Also, what movements would they govern?

 

7) finally (for now!) how would trains arriving from either direction, drop off or collect wagons from the goods yard? I know there were no special rules regarding the yard being served by trains travelling in one direction only, but the loop formed by points 8, 11, 14 and 15 isn’t huge and the blind siding doesn’t look to have been long enough to serve as a headshunt. Would the loop formed by the up and down lines have been used to run around goods trains?

 

Sorry about all those questions - there didn’t seem to be so many when I was pondering them in my head!

 

Thanks for the help in advance!

 

Nik

 

Q1. Maybe the draughtsman forgot it? Not unknown. I suggest that you ask the SRS.

 

Q2. Yes, as they appear to be marked MFB (Mechanical Fouling Bar).

 

Q3. Given the way that it is drawn, then (a)  17 locked both points and (b) there would probably be one locking bar working both the lock plungers.

 

Q4.  Maybe that was L&NWR practice at the time? Not my speciality :-)

 

Q5.  Usual principle is top to bottom = left to right routes

 

Q6.  Y= Yellow shunt, hence worked only for the diverging route.

 

Q7. At a rough guess, the main loops would be used for stabling/running-round. The engine would attach/detach traffic from the relevant end of the train.

[Tortuga]

1 hour ago, Flying Pig said:

This might work - Alsop en le Dale is on the LMS page: https://www.s-r-s.org.uk/drawings.php

@Poor Old Bruceon page 5, drawing S6 to be precise. Don’t know why my link didn’t work; it does for me...

 

1 hour ago, Flying Pig said:

I'm guessing the 'Y's indicate yellow shunting signals, which would be interesting as the diagram seems to show them as LNWR types.

Does that mean they can be treated like distant signals? As in can be passed when ‘on’ as long as the driver is prepared to stop at the next signal?

Oddly, the only photo I’ve seen of them dates from 1961 and shows 12 (at least) to be (I think!) a standard BR ground signal - unfortunately the photographer was behind the signal so you can’t see the disc! More oddly, 6 and 7 definitely were LNWR types.
 

1 hour ago, Flying Pig said:

Stacked discs are read left to right from top to bottom.

So if I understand you correctly, 7 would control setting back along the down main, while 6 would control setting back into the goods loop?

 

[RailWest]

'Yellow' discs mean that you can ignore/pass the disc if the point ahead is NOT set for the route for which the signal applies. When the point IS set for that route, then in effect you treat the signal the same as a 'red' one. Therefore the signals applied ONLY when the points were set for the 'crossover' route onto the main line.

 

In effect, a method to allow a train in the sidings to run up and down between the dead ends without (a) the signalman needing to keeping clearin the discs or (b) the driver having to keep passing a 'red' signal at danger.

[beast66606]

You've already had most points answered so not repeating.

 

2 - I suspect it's MCB, mechanical clearance bar, and both could be worked by lever 4 (which is not logical) but they might even be 4 and 22 and the diagram is wrong on 2 counts - without more info it's hard to be sure.

4 - the LNWR frequently worked crossovers by 2 levers, a lot depends on the locking requirements, the distance from the cabin and the rod run - 2 points off 1 lever are harder to set up and maintain

[Tortuga]

Thanks for clearing that up @RailWest! That makes perfect sense now I think about it, but I swear I’d not come across yellow ground signals before - I’m sure my “Railway Signalling and Track Plans” doesn’t mention them...

 

EDIT: tell a lie. It does; on page 55, in the section on ground signals strangely enough. In fact, it also states how they should be read when there is more than one on a post…

See I have all these resources, just never to hand when I have time to ask the questions…

Edited June 8, 2021 by Tortuga
See text

[meil]

Just one matter - I would have expected a running dummy relating to point 15.

[beast66606]

17 minutes ago, meil said:

Just one matter - I would have expected a running dummy relating to point 15.

 

Probably not required as traffic for the yard would normally enter via 8/10 and signal 6, and rarely via 15/16 - so a flag would suffice when required. The LNWR were not overly generous with ground signals.

[Tortuga]

Thanks for your replies gentlemen; they’ve helped my improve / confirm my understanding.

Please bear with me while I seek clarity on a couple of points

 

37 minutes ago, beast66606 said:

2 - I suspect it's MCB, mechanical clearance bar, and both could be worked by lever 4 (which is not logical) but they might even be 4 and 22 and the diagram is wrong on 2 counts - without more info it's hard to be sure.

Is there a difference between a fouling bar and a clearance bar or is it just different terminology for the same thing? I understood a fouling bar to be a length of metal that lay against the inside of one rail and, when depressed by the wheels of a train/engine, prevented other levers in the signal box being pulled, thus preventing collisions at fouling points on the track layout. I didn’t appreciate they had their own lever? How did they work? Can you clarify why it isn’t logical for lever 4 to work both fouling/clearance bars? Or am I being thick (wouldn’t be the first time)?

 

49 minutes ago, beast66606 said:

4 - the LNWR frequently worked crossovers by 2 levers, a lot depends on the locking requirements, the distance from the cabin and the rod run - 2 points off 1 lever are harder to set up and maintain

Would one half of the crossover be interlocked with the other somehow in that case? Logically there’s no point in being able to switch one turnout to a diverging route while the other is set straight, so am I right to assume that both the turnout levers would need reversing to allow the relevant signal levers to be reversed?

[bécasse]

2 minutes ago, beast66606 said:

The LNWR were not overly generous with ground signals.

That is almost the signalling understatement of the year! The LNWR were distinctly parsimonious with signalling generally, including the provision of box structures and the avoidance of traditional lever interlocking (particularly by clever use of sequential Annett's Keys - for which the LNWR had purchased a generic licence).

[Tortuga]

27 minutes ago, meil said:

Just one matter - I would have expected a running dummy relating to point 15.

If by running dummy, you mean a ground signal, then so would I!

[Tortuga]

10 minutes ago, beast66606 said:

 

Probably not required as traffic for the yard would normally enter via 8/10 and signal 6, and rarely via 15/16 - so a flag would suffice when required. The LNWR were not overly generous with ground signals.

See, I’d assumed exactly the opposite! I thought a train on the up line would detach wagons and engine from the front of the train, run forward of 16, then set back into the yard via 15/14, while a train on the down line would detach the engine, run around via the up line, detach wagons from the rear of the train, set back past 15 then propel into the yard.

Now 6 and 7 and the lack of signal at 15 make more sense! A down train would stop alongside the platform, detach the engine, run round via the up line, couple up to the rear, detach wagons from the rear and set back into the goods loop via 8 and 11 being authorised by 6. Once the wagons were in the yard, 12 would allow access to the down line, then 7 would permit setting back beyond 16 before the engine ran round to the front of the train again: does that sound right?

 

Still not 100% sure how it’d work for an up train though...

[beast66606]

35 minutes ago, Tortuga said:

Thanks for your replies gentlemen; they’ve helped my improve / confirm my understanding.

Please bear with me while I seek clarity on a couple of points

 

Is there a difference between a fouling bar and a clearance bar or is it just different terminology for the same thing? I understood a fouling bar to be a length of metal that lay against the inside of one rail and, when depressed by the wheels of a train/engine, prevented other levers in the signal box being pulled, thus preventing collisions at fouling points on the track layout. I didn’t appreciate they had their own lever? How did they work? Can you clarify why it isn’t logical for lever 4 to work both fouling/clearance bars? Or am I being thick (wouldn’t be the first time)?

 

Would one half of the crossover be interlocked with the other somehow in that case? Logically there’s no point in being able to switch one turnout to a diverging route while the other is set straight, so am I right to assume that both the turnout levers would need reversing to allow the relevant signal levers to be reversed?

 

LNWR  - at least on the Birkenhead Joint - called them clearance bars, but they are the same thing.

 

4 would be unlikely to work both as the two halves of the loop are independent of each other and trains standing in the loops could lock each other out, more likely 4 would work the Ashbourne end and 22 would work the other end, so, for example, 3 would be released by 4 proving that nothing was foul at that end.

 

Yes, when a crossover is worked by two levers there will be locking to mandate both levers are reversed- for example at A-e-l-D signal 7 will be released by 11 which will be released by 8

[beast66606]

21 minutes ago, Tortuga said:

See, I’d assumed exactly the opposite! I thought a train on the up line would detach wagons and engine from the front of the train, run forward of 16, then set back into the yard via 15/14, while a train on the down line would detach the engine, run around via the up line, detach wagons from the rear of the train, set back past 15 then propel into the yard.

Now 6 and 7 and the lack of signal at 15 make more sense! A down train would stop alongside the platform, detach the engine, run round via the up line, couple up to the rear, detach wagons from the rear and set back into the goods loop via 8 and 11 being authorised by 6. Once the wagons were in the yard, 12 would allow access to the down line, then 7 would permit setting back beyond 16 before the engine ran round to the front of the train again: does that sound right?

 

Still not 100% sure how it’d work for an up train though...

 

Note - my comment is an assumption, typically* if a signal wasn't provided it wasn't a regular move *but not always. Goods yards were often worked by trains from one direction only, you'd need to check the local instructions / timetables for A-e-l-D to see if this was the case.

[RailWest]

Again, not from specific L&NWR experience, but....

 

Although there were instances where MFB/MCB were worked by their own lever, there were also instances where they were worked by the same lever as the adjacent points. In the case of somewhere like Alsop, the basis idea would be to prevent a set of points at the exit from a loop being reversed if the tail end of a train on the other loop was sitting foul of the connection.

[RailWest]

>>>Is there a difference between a fouling bar and a clearance bar or is it just different terminology for the same thing?

 

Essentially a combination of the latter, how it was being used, and the railway company concerned.

 

>>> I understood a fouling bar to be a length of metal that lay against the inside of one rail and, when depressed by the wheels of a train/engine, prevented other levers in the signal box being pulled.....

 

In which case, you are talking about a depression bar, which was usually electrical. The concept of a  mechanical fouling/clearance/safety bar (call it what you like) was that - whether worked by its own lever or that of (say) a set of points - it was normally lowered and could not be raised if there was a train standing above it, thereby preventing the relevant lever from being pulled. By contrast, an electrical depression bar stood normally 'up' (ie foul of the flange-way) and its depression by a passing (or standing) train broke the circuit that would have otherwise released the electrical lock on the relevant point lever.

[Michael Hodgson]

3 hours ago, meil said:

Just one matter - I would have expected a running dummy relating to point 15.

I don't see the need.  I would expect trains to enter the siding via the other crossover, so there's no need for a shunt signal there, and for trains approaching the platform, the points are close enough for it to be sufficient that the points were set and locked normal to clear the Home Signal, particularly given the provision of the clearance bars

[Michael Hodgson]

I don't know whether the box could be switched out.  If it could there would be a King lever which rearranged the locking to allow you to set the road via one of the platforms and clear all the running signals in both directions.  One the commonest omissions when drawing a signalling plan is the King lever.  However if the box could switch out, I would expect a junction Home signal for the reversible platform and an additional starting signal from that platform.  Detonator placers, ground frame releases and gongs are other typical omissions, though all of those seem unlikely here. 

 

Some signalbox diagrams (from which this might simply have been copied) include a table or list of the spares, other styles do not.  When a signal is removed, it is erased from the diagram (sometimes with a piece of paper stuck over it), but it is by no means unknown for the table not to be updated, or for a piece of paper with the lever number to be stuck on (and ignored if it falls off).  Also sometimes people drawing such diagrams draw a distinction between Spares (levers not used) and Spaces (where the spare lever is not present in the frame, just an empty quadrant in the frame).

[RailWest]

You might want to take a look at the diagram here

 

https://signalbox.org/~SBdiagram.php?id= 1057

 

which may answer a few questions.

[beast66606]

13 minutes ago, RailWest said:

You might want to take a look at the diagram here

 

https://signalbox.org/~SBdiagram.php?id= 1057

 

which may answer a few questions.

 

Generally confirms my comments, but with co-worked clearance bars rather than independent.

 

Signals 6 and 7 were LNWR revolving ground signals until at least 1963, probably until closure, they are visible in a J.W.Sutherland photograph.

[Michael Hodgson]

2 hours ago, RailWest said:

You might want to take a look at the diagram here

 

That excellent site had occurred to me, I should have checked it when I posted earlier!

[Tortuga]

@RailWestIf only I’d found that site earlier, it would’ve saved a bit of supposition!

Looks like that answers the question of the “missing” 4 lever and given the clearance bars are labelled the same as turnouts 10 and 16, I guess they’re operated from the same lever as you mentioned earlier.

The diagram also confirms that lever 17 operated both facing point locks for 15 and 16.

 

Thank you all for all your help: I’m certain I’ll need further help once I get further into building my layout!