Signalling Awrhyygwami Quarry

[Penrhos1920]

 

Signalling Experts help please. This is the expanded Awrhyllgwami Quarry trackplan and I’ve added some signals. Have I got them in the correct places etc? I have not numbered the turnouts ooops. AQ was originally signalled LSWR, then SR and then transferred to BR(W). Generally it is set in 1970s & 80s. There are through passenger trains in both directions non stop. The occasional DMU stops at the halt. Up parcels and goods are occasionally looped using signal 10.

 

Empty ballast trains enter on the Down line and stop at 3. The loco draws forward (signal needed?) and reverses onto the down line using 21, runs along Up line (Would 24need to be pulled?) and returns to the rear of the train either by 13 or 18. It then draws the train into the quarry, 16 or 17? If a train is longer than the distance between 16 and 3 would 3 need to be pulled so the train could be pushed back to clear the quarry entrance?

 

Empty ballast trains enter on the Up line and stop at 8. 24 is pulled off and it pulls clear of 18. 18 is pulled off and it reverses onto the Down line as far as 16/17. It then draws the train into the quarry, 16 or 17?

 

Loaded ballast trains leave the quarry being pushed onto the Down line. Up trains simply depart using 16/17 and then 9. For a Down departure, the loco runs around using 16/17, 18, 22 & 21, each pulled as the loco approaches. As the loco will not of passed 3, it pulls forward to 4 and departs.

 

As shunting the quarry requires the headshunt to be used, does there need to be a second disc adjacent to 15 and another on the quarry side of those points so that a loco knows when it is allowed to enter the headshut? Is this where a yellow disc might be used?

 

On the current AQ we only have signals 3, 8, 16, 17 & 24.

[ikcdab]

My comments would be:

 

7 and 11 are unlikey to be a bracket and would probably be 2 single post signals.

you would need something to protect the uploop points and i would have thought 22 could be a double disc to read both over crossover and into the loop.

I dont know what you have both 8 and 24. i think this could just be 8 only - it is likely to be much closer to the crossover.

The signal you currently have numbered as 5 is likely to be the highest numbered lever in the box with the stop signals numbered below it.

I am not sure why the intermediate crossover is provided. I suspect this would have been removed through rtionalisation and means you could save 18.

 

Hope this helps.

[Penrhos1920]

My comments would be:

 

7 and 11 are unlikey to be a bracket and would probably be 2 single post signals.

you would need something to protect the uploop points and i would have thought 22 could be a double disc to read both over crossover and into the loop.

I dont know what you have both 8 and 24. i think this could just be 8 only - it is likely to be much closer to the crossover.

The signal you currently have numbered as 5 is likely to be the highest numbered lever in the box with the stop signals numbered below it.

I am not sure why the intermediate crossover is provided. I suspect this would have been removed through rationalisation and means you could save 18.

 

Hope this helps.

 

The signals are only numbered as I thought through what is needed. I realise they would be completely different in the lever frame.

 

I don't envisage any reverse moves into the up loop, but a second disc at 22 is a good idea. Would it be above, below, left or right of 22?

 

Signal 24 is an old LSWR shunt signal with horizontal white line - sorry it does not show up too clearly on the diagram. As I understand from the builder it is roughly equivalent to a ground disc for shunting ahead as far as the limit of shunt.

 

8 is only a locos length from the crossover. The layout as originally built is from the middle crossover to signal 3. What is shown above is the planned expansion. The middle crossover works well and is one of the most reliable pieces of trackwork on the layout and it seems a shame to remove it, even though it is in the wrong place. A more drastic rebuild would put in an down loop from the left hand crossover to signal 3. But that will involve lots of extra changes that we'd rather avoid. Maybe we'll just leave the crossover there and put it out of use?

[The Stationmaster]

My comments would be:

 

7 and 11 are unlikey to be a bracket and would probably be 2 single post signals.

you would need something to protect the uploop points and i would have thought 22 could be a double disc to read both over crossover and into the loop.

I dont know what you have both 8 and 24. i think this could just be 8 only - it is likely to be much closer to the crossover.

The signal you currently have numbered as 5 is likely to be the highest numbered lever in the box with the stop signals numbered below it.

I am not sure why the intermediate crossover is provided. I suspect this would have been removed through rtionalisation and means you could save 18.

 

Hope this helps.

 

Further to ikcdab's comments - I would be very surprised indeed, especially on something in WR ownership post 1960s (which what I would think the case), to find 7 & 11 bracketed like that. It happened very occasionally on the western but it was rare and if they'd inherited it they would have altered it. And as already noted distant signals usually take the lever at the end of the frame nearest to them - so your No.5 would be No.1 and your No1 would be No.24, with everything else renumbered to suit keeping the points and their associated discs to roughly the middle of the frame

All discs should be single - that's how they would have come from Southern ownership and by that time the Western was out of multiple arm disc arrangements in any new work, 22 should be moved to cover the loop points as well.

Very definitely one crossover too many for the 1970s/later, but whichever of those which survives 'towards the left' on your drawing depends on train length - nearer the 'box the better (provided trains have room to run round).

I am very puzzled by 24 and can't really work out why it's there, what it is meant to do and what sort of signal it would be - get shot, it serves no purpose at all.

 

 

I'm also a bit confused by your use of 'LofS' which I presume means 'Limit of Shunt'? If it does you are showing the letters against the wrong line as LoS boards/signs are used to limit movements in the wrong direction, signals serve to limit those in the right direction (i.e. signals 4 & 9).

[Penrhos1920]

All discs should be single - that's how they would have come from Southern ownership and by that time the Western was out of multiple arm disc arrangements in any new work, 22 should be moved to cover the loop points as well.

 

Ok. Would pulling 22 off mean that either route to the loop or down line was clear?

Very definitely one crossover too many for the 1970s/later, but whichever of those which survives 'towards the left' on your drawing depends on train length - nearer the 'box the better (provided trains have room to run round).

Ok, one of them will be ditched. I suspect the left hand crossover as it hasn't been built yet.

I am very puzzled by 24 and can't really work out why it's there, what it is meant to do and what sort of signal it would be - get shot, it serves no purpose at all.

 

A fair as I understand from Roger who built this signal:

24 is a shunt ahead signal that allows the train to pass 8 whilst on before reversing onto the down line.

[Grovenor]

Ok. Would pulling 22 off mean that either route to the loop or down line was clear?

Yes if both routes were provided, the route to the loop is an option that would only be provided if it is expected that trains or parts of them may be left there when shunting and you need to add wagons to the train or similar moves, the entry end of the loop must have a trap point to allow this sort of move (but both ends of the loop should have anyway).

 

Ok, one of them will be ditched. I suspect the left hand crossover as it hasn't been built yet.

OK that will be an improvement, 3 crossovers is definately overkill, and remember all rod operated points should be within 350 yards of the box (and modellers yards are compressed) 250 yards if they were pre-group. If you consider the loop probably started life as a lay bye where trains had to reverse in, hence needing 22 to have a route to the loop, then wartime needs would have added the loop entry points with a motor to operate them if more than 35o yds. Note that shunt signals should not read to a wrong road move if it can be avoided, so shunts allowing setting back for run-rounds etc will require the next crossover reversed so if the move goes to far it ends up back on the right line.

(Be a lot easier to explain if the points had numbers )

 

 

As far as I understand from Roger who built this signal:

Attached Image: PB220001.JPG

24 is a shunt ahead signal that allows the train to pass 8 whilst on before reversing onto the down line.

Well yes it would but normally 8 would be used for such a move, you would only need the shunt arm if you needed to pull forward onto an occupied line, hence this type of signal usually applies at platforms where you need to add vans etc or fit two trains in.

 

Regards

Keith

[Wizard of the Moor]

Ok, one of them will be ditched. I suspect the left hand crossover as it hasn't been built yet.

 

Wasn't the idea of the leftmost crossover to permit trains to cross the viaduct (to the left of the leftmost crossover) running wrong line?

 

If different batches of K&S tube expand at different rates, then this might be a necessary maneuver under exhibition conditions

[beast66606]

Picking up on a few points made,

 

There is no requirement for a shunt ahead at the location drawn, it's normally on a starting signal to allow trains to pass the main arm at danger for shunting, but not to proceed to the next box. I think Keith is referring to a calling on arm.

As StationMaster says Limit of Shunts are not for normal line moves, think of them as a fixed red, if they were on the right line nothing could pass them.

 

Facing points had to be within 350yds, trailers could be further away, and sprung points even further.

[TheSignalEngineer]

Facing points had to be within 350yds, trailers could be further away, and sprung points even further.

 

The 350 yards limit applied to all rod worked points, not just Facers. In fact as heavier track and longer switches came into use this was reduced to 250 yards on at least one region of BR. Motor worked points could be at any distance from the signal box.

[beast66606]

The 350 yards limit applied to all rod worked points, not just Facers. In fact as heavier track and longer switches came into use this was reduced to 250 yards on at least one region of BR. Motor worked points could be at any distance from the signal box.

 

Which region ? - and was this for all mechanical points or just particular ones ? I still stand by the facing* points had to be 350yds max for rods** (which is a subtle introduction to the discussion, wire of course could be a lot further) but once again we wander into unnecessary complications.

 

* some loop exit points had the facing connection at the limit and the trailed only connection beyond, granted not applicable in this case.

 

**We aren't talking current group standards which do stipulate a maximum of 350 yards, but then they stipulate a mechanical signal is limited to 1,100 yards and I've pulled plenty which were further away than that.

[TheSignalEngineer]

Which region ? - and was this for all mechanical points or just particular ones ? I still stand by the facing points had to be 350yds max for rods (which is a subtle introduction to the discussion, wire of course could be a lot further) but once again we wander into unnecessary complications.

 

MoT requirements didn't make a distinction between facers and trailers at 350 yards maximum. References go back to at least February 1925.

 

LMR local instructions in the 1970's or 80's were more restrictive with especially with regard to multiple ends, 113lb rail and longer switches. This went through into BR/Railtrack practice at a later date.

 

I remember one lever back on a job we installed in the 1960's where the run was so complex that it was difficult to pull the points up at 200 yards.

[beast66606]

MoT requirements didn't make a distinction between facers and trailers at 350 yards maximum. References go back to at least February 1925.

 

Doesn't mean they were always adhered to though

 

LMR local instructions in the 1970's or 80's were more restrictive with especially with regard to multiple ends, 113lb rail and longer switches. This went through into BR/Railtrack practice at a later date.

 

But these are special cases, which highlights my point (groan) about introducing/adding complications which aren't relevant to the model, no-one doubts anyones knowledge but most of the time, "less is more", if the o.p. wants further info they can come back and ask, otherwise all we do is confuse.

 

I remember one lever back on a job we installed in the 1960's where the run was so complex that it was difficult to pull the points up at 200 yards.

 

Me too - I've pulled some real stiffys in my time.

[The Stationmaster]

Ok. Would pulling 22 off mean that either route to the loop or down line was clear

Already answered but to confirm - yes - if a route is required to both but in all likelihood on the Southern provision would have been made anyway. But you would need a Limit of Shunt sign at the far end of the loop just short of the trap (not that they were always provided in such circumstances but the Western would have out one in when they took over knowing their habits).

A fair as I understand from Roger who built this signal:

24 is a shunt ahead signal that allows the train to pass 8 whilst on before reversing onto the down line.

 

 

 

A shunt ahead signal is only provided beneath the signal controlling entry to the block section in advance as it confers authority to make a shunt move into the section. For your move all that is necessary is to clear the running arm - which is why that is all that is needed at this signal.

[Penrhos1920]

Wasn't the idea of the leftmost crossover to permit trains to cross the viaduct (to the left of the leftmost crossover) running wrong line?

 

If different batches of K&S tube expand at different rates, then this might be a necessary maneuver under exhibition conditions

 

I read that 3 time before I understood what you meant. You are cruel. Does that mean we ought to erect the viaduct in exhibition conditions? Not a job for the winter then?

[Penrhos1920]

Thanks for your help guys, I've taken heed of your comments and redrawn the plan. If I've missed your point please shout up. Points are now numbered and the numbering is up line first right to left, or left to right when standing at the frame facing the running lines. Numbers in the description below updated, I hope.

 

 

Empty ballast trains enter on the Up line and stop at 6. 6 is pulled off and it pulls clear of 19. 18 & 19 are pulled off and it reverses onto the Down line beyond 16. 17 & 16 are reversed and the train draws into the quarry.

 

Empty ballast trains enter on the Down line and stop at 23. As the train maybe long, 23 is pulled off and the train draws forward, so that the rear is clear of 17. The loco then uncouples and draws forward. 12 & 11 are pulled off and it reverses onto the down line, runs along Up line (6 is pulled off) and returns to the rear of the train once 18 & 19 are pulled off. 17 & 16 are reversed and the train draws into the quarry.

 

Loaded ballast trains leave the quarry being pushed onto the Down line after 17 and 20 are pulled off. As the train is likely to be longer than the length between 17 and 23, 23 is also pulled off.

 

Up trains simply depart using 18, 16 and then 7. For a Down departure, the loco runs around using 16, 18, 19, 12 & 14. It reverses on to the train using 11 As the loco will not of passed 23, it pulls forward to 22 and departs.

 

20 is yellow as shunting the quarry requires the headshunt to be used.

[flyingsignalman]

You could add a stop signal / ground disc reading from the quarry (as marked on your plan) reading to the down siding.

This would protect shunting moves into the siding from the down main.

You could number it 15 and perhaps have it standing "normally off" (requiring lever 15 to be pulled to put it back to danger).

[Penrhos1920]

You could add a stop signal / ground disc reading from the quarry (as marked on your plan) reading to the down siding.

This would protect shunting moves into the siding from the down main.

You could number it 15 and perhaps have it standing "normally off" (requiring lever 15 to be pulled to put it back to danger).

 

Like this?

 

 

So to reverse 17, 15 would have to be pulled first. Would N.O. be written on the diagram?

 

Thanks

[The Stationmaster]

Like this?

 

 

So to reverse 17, 15 would have to be pulled first. Would N.O. be written on the diagram?

 

Thanks

 

The signal would be drawn in the 'off' position. I'm not sure about the Southern but this was not very common practice on the Western where it was preferred that a lever standing normal in the frame meant the signal was 'on' (and if the signal was left 'off' you kept on clouting yourself in uncomfortable places as you walked along the frame with the lever standing reversed all the time.

 

 

 

 

 

 

 

 

 

 

 

;;

[Grovenor]

You only really need 15 if the quarry has its own shunting engine, if all the shunting is done by the train engine then your original setup with the yellow disc is enough.

It would be unusual in my experience to have 20 yellow if 15 exists, I would expect both to be red, both to be at stop with the levers normal, and the locking arranged to allow both signals to be cleared together for shunting with 17 normal.

A fairly common arrangement on the LM, the stationmaster will know better about the Western.

Regards

Keith

[beast66606]

It would be unusual in my experience to have 20 yellow if 15 exists, I would expect both to be red, both to be at stop with the levers normal, and the locking arranged to allow both signals to be cleared together for shunting with 17 normal.

A fairly common arrangement on the LM, the stationmaster will know better about the Western.

Regards

Keith

 

I would agree that if 20 is provided then 15 should be red, but I would expect both to be off with levers normal, certainly on the LM, and for OLR to be implemented, as you say, to allow this. (Opposing locking relaxed) - and the signals would be marked "normally off" on the diagrams (again talking LM)