Assistance with signalling - BR(WR) early 1970s

[br2975]

I would be grateful for the assistance of those better versed in BR (WR) signalling than I.

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Research and development for the 'magnum opus' a.k.a. the retirement project is now under way.

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To set the scene;

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The layout is set in the South Wales valleys during 1971and depicts a junction located at the confluence  of two river valleys.

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The junction layout was re-modelled by the GWR during WWII and a workmens platform built between the up and down main, and this was served by passenger services along both the main, and branch.

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When remodelled by the GWR the signalling installed was of the tubular post variety, and a new 'austerity' 'box built.

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By 1971, the hourly passenger service still operates, along the main line, up and down the valley.

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The 'branch' has recently been rationalised (singled) with the former 'down' line taken out of use, and now lifted.

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All services along the branch (including a two-hourly bubble car, that doesn't always connect with the main line DMU services.... very suspicious) now use the former 'up' line of the branch.

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As a result, all 'down' services off the branch cross the 'down main' north of the station and pass through the 'up' platform, before regaining the 'down main' just south of the station.

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On the west side of the 'up main' are exchange sidings for a local industry (NCB) into which both BR and NCB locos work.

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On the 'east' side of the 'down main' are located three sidings which hold traffic to/from  for the exchange sidings and also occasional traffic from one valley to another.

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It appears that a Radyr Cl.37 spends much of the day working from here.

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In light of this brief, potted history, could those with 'the knowledge' indicate how this junction would be signalled, and sketch a 'box diagram please ?

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Brian R

[The Stationmaster]

Brian,

 

The recent rationalisation of the branch would, I feel, have been far more likely to retain the Down line connection at the junction and this eliminate the awkward to maintain diamond (such things as the then Regional Chief Civil Engineer was very keen to get rid of, the one at my own branch junction went in that very year as did those at Pontypridd of course).  Doing it the way I suggest also makes the signalling simpler (although the interlocking alteration would have been a bit more complicated, but they didn't seem to worry about that in those days).  But it does involve a bit of a shuffle across the layout for anything from the Up Main to the nbranch (in reality a facing crossover wold have appeared if the traffic existed to justify it - does it?

 

I do wonder also about the single slip in the Up Main although in view of the number that were still tolerated at that time it would only be removed if it was falling apart - daft to spend money on valley lines that have no future was i believe the mantra of the day.

 

Before sketching in some signalling and bearing in mind its history it would help to know what sort of distance there will be between the three trailing pints in the Down Main at the left end of the station please.

[RJS1977]

I was just thinking the same thing about the branch - the way it's drawn any train coming off the branch and heading for the down line is going to unnecessarily block the up line...

 

I would have expected in that instance for there wither to be a single lead junction (i.e. with a crossover from the up to the down line, followed by the divergence) or for the pointwork for the downbranch  line to have remained in place but to have connected in to the up branch line  instead of remaining independent (can't just remember what that type of junction's called!).

[br2975]

Thank you chaps.

 

As the plan is not drawn to scale, that may cause problems ...... hence some explanatory notes.

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Please find below Ver.2.

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Amendments to Ver.1 are:-

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(i) - assume no rationalisation has taken place and the branch remains double track and accessed as shown.

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(ii) - The two switches on the down main / platform road. i.e that giving access to the down sidings thro' the double slip, and the other giving access across the up main into the exchange siding(s) are immediatley adjacent to each other -

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(ii-a) - a train can stand at the down platform, whilst a freight leaves the down sidings through the double slip and onto the down main - i.e. without running along the "headshunt / shunting neck / loop".

However, the signalling should allow for a freight to leave the down disings along the 'headshunt/shunting neck/loop' and gain the down main at the extreme left hand end of the plan.

 

(iii) - the 'headshunt / shunting neck / loop' that allows the shunting of the three down sidings will hold about 20-25 SLU plus a loco in the loop, with enough room for the pilot (Cl.08) and van to stand in the extreme (left hand end) of that headshunt, past the final crossover giving access to the down main.

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In addition, in light of space constraints and traffic movements, where would be the most likely position for the 'box.

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As the plan is at an embryonic stage, space can be found at most locations around the station/junction site.

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Only what is drawn, will be modelled so the extreme edges of the plan shown here will be the scenic breaks.

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I thro' it open to the floor - please feel free to air all your views, regardless (my shoulders are very broad !).

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Brian R

[br2975]

Would NCB locos have worked into the exchange sidings over point work controlled by the GW box; i.e. the double slip?  I would have thought that that the BR shunter would have "tripped" further down the bi-directional line to the colliery?   Depending on length / local conditions, a number of different operational methods over the single track freight line could have been in force.  If it was train staff, then having the box at that end would have been more convenient.

 

Perhaps those taking up the gauntlet could allow for either, namely (i) BR exchange sidings to which the NCB locos have access, and/or (ii) NCB exchange sidings to which BR locos have access.

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Brian R.

[Happy Hippo]

Brian,

 

Just to throw a spanner into your works, why not move the platform(s)?

 

Think Aberbeeg, Blackmill, or Brynmenyn as examples where the platform lay in the 'triangle' formed by the tracks diverging

 

It would mean the bubblecar could then operate on the branch without an incursion onto the main line.

 

another question....is the branch pax only or do you intend to serve some small colliery?.

 

This would probably be more reason to keep the branch open than the passenger service.

 

always pleased to ad to your headaches!!

 

Regards

 

Richard

[br2975]

 

(1)

Just to throw a spanner into your works, why not move the platform(s)?

 

Think Aberbeeg, Blackmill, or Brynmenyn as examples where the platform lay in the 'triangle' formed by the tracks diverging

 

It would mean the bubblecar could then operate on the branch without an incursion onto the main line.

 

(2)

another question....is the branch pax only or do you intend to serve some small colliery?.

 

This would probably be more reason to keep the branch open than the passenger service.

 

 

 

Richard ( stirrer )

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To answer your points.......

 

(1)

There was insufficient land available to build the station in the 'V' - the "station" is a mere  'workers platform' (e.g. Tynycwm or Treforest Estate) built on a shoestring during WWII as a stop-gap, but which has lingered in use until the early 70s (the main line services will survive, but the sword of Damocles hangs above the bubble car on the branch).

 

Facilities at the 'station' only ever reached a brick built booking office (and store) with cast concrete roof, and a (thoroughly useless) shelter built from second-hand rail clad with asbestos sheeting, a la 'Worthy Down' on the D.N.&.S.

 

(2)

Currently the branch operates a sporadic service using a Canton based single car DMU - which, if one reads the right calendar, and travels only on a solstice, may provide a connection with the Derby suburban set running along the main line twixt the coast and head of the valley.

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By using the plan in Version 2 I suspect better physical connections could be made with main-line and branch services at the platform at the same time, signalling permitting.

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The branch does support a freight service, no general traffic of note (but not unknown) predominantly coal - with fulls 'down' and empties 'up'.

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Brian R

[Happy Hippo]

Brian,

 

Thanks for the more detailed explanation of the service in the area.

 

Depending on the traffic you have on the branch, would a facing connection off the down branch into the 'No 1' siding on the down side, turning it into a goods only loop/platform avoiding road give you a little more flexibility?

 

The other point which need clarification is the status of the 'up' branch.

 

Although your traffic levels are very low, it is going to be a pig of a reversal to get up coal trains onto the branch without reversal, which is something I'm sure the traffic people would try to avoid. (Especially at night).

 

I know the Nantgarw colliery link was singled prior to closure, and the double junction was replaced with a facing crossover and a single lead onto the branch.

 

I'm not sure of the dates but the photos were probably taken after traffic was suspended coming down from Aber Junction, so probably mid 80's?

 

See the photo about half way down the page: http://www.roscalen.com/signals/WalnutTreeJct/index.htm

 

you can see that the up and down relief lines have long gone, although they stayed in place south of Walnut Tree for a few more years.

 

Regards

 

Richard

[The Stationmaster]

Coming along nicely Brian - I think the 'industrial branch' could just as readily be industry rather than railway owned with 'their' loco(s) running into the exchange sidings which would give a greater variety of motive power and would make sure you could still have a pannier (well it's the Valleys so you  must have a pannier doing something).

 

For info ref Richard's comment above the Nantgarw branch was singled in 1973, the new facing crossover was  officially 'bl**dy heavy' and the FPLs were even worse until the S&T had spent about 3 weeks getting them right  (oh and the possession and the subsequent calls by irate Signalmen about the heavy crossover were worth a few bob in overtime which went towards a 200mm Pentax telephoto lens).  And just to get Brian thinking if we did a clearance of Nantgarw on a Sunday in order to retrieve empties (it received more coal than it despatched in those days) it was nothing to come down the branch, and on to Radyr, with about 120 for length; great days.

 

Drawing pad out tomorrow - unless you change it again Brian.

[br2975]

Richard,

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The primary function of the three 'down sidings' is to hold traffic to/from the exchange sidings.

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As I wanted a bit of a difficulty factor built in, the 'down sidings' find only occasional use holding and/or reforming inter-valley traffic  - but those levels are low.

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There is a possibility that the NCB 'exchange sidings' could instead form part of the Metal Box Co. Twll Cach works (formerly an R.O.F. - hence the building of the station during WWII)  - which would allow a little more variety of rolling stock other than an endless stream of sixteen tonners.

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The Metal Box Co. option gets more appealing, and in order to attend to servicing that factory, the 'down sidings' and some offstage local trip working  - we may find a Canton Cl.08 outbased here, but I think a Cl.37 working out and back from Radyr may be more likely. 

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Those are the main traffic patterns then.

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Here is some inspiration:-

http://www.rcts.org.uk/features/mysteryphotos/show.htm?srch=Morriston&serial=3&img=G-031-28

http://www.rcts.org.uk/features/mysteryphotos/show.htm?srch=B-66-28&img=B-66-28

http://www.rcts.org.uk/features/mysteryphotos/index.htm?location=&srch=B-66-35&page=0

http://www.rcts.org.uk/features/mysteryphotos/index.htm?location=&srch=B-68-14&page=0

http://www.rcts.org.uk/features/mysteryphotos/show.htm?srch=Caerau&serial=9&img=Y-35-26A

http://www.rcts.org.uk/features/mysteryphotos/show.htm?srch=Caerau&img=Y-35-23A&serial=7

 

 

Brian R

[br2975]

 

Drawing pad out tomorrow - unless you change it again Brian.

 

No chance Mike.

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Regardless of any operational limitations - I  like it, and hopefully that will hopefully form the retirment project.

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Brian R

[Happy Hippo]

Brian,

 

It all sounds rather grand as well as good fun.

 

I'm afraid that my hankerings for South Wales are on a very much smaller scale than yours.

 

I presume this magnum opus will be 4 mm scale: But what gauge? At one stage you were making mutterings of EM.

 

Further to Mike's comment about the stiff pulls at Walnut Tree junc for the Nantgarw branch: I can vouch for his comments. The old double junction was just about at the limit of length a signalman could pull off, and when I visited the box on occasions and was offered the chance to have a go, as a 14 year old I found it nigh on impossible to set the road for Nantgarw.

 

I was ok with the signals tho'!

 

Excellent set of pictures. They make me quite homesick.

 

Regards

 

Richard

[The Stationmaster]

Richard,

 

I assume you mean down empties arriving and then reversing to run up the branch? I which case, I agree.  

 

As we are talking 1971, there would still be unfitted 16 tonners around.  The only means of running around and getting the brake van at the rear, is by using the down shunting loop for the down sidings (unless you want to use the one on the up exchange sidings, which would be highly improbable).  Having got the loco and brake van at the right ends and depending where the down section signal ends up, you may well have to shunt forward into the next block section, prior to reversing over the crossover onto the up main.  You then run through the platform to the junction for the branch. If the down "shunting" loop is short, things could become really tied up!

Easy peasy Paul - apart from getting the brakevan to the other end - just send the engine away in the Down direction to come back on the Up line from the next signalbox  (as long as the gradients are ok for such fun & games). And assuming it was downhill all the way from the Up direction I can guess how it might have been done at night when officialdom was safely tucked up in bed or the pub - although we did have one gent whose 'extra mural interest' lived up the Rhondda and whose progress was closely followed up & down the valley of an evening.

[br2975]

Richard,

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The 'station' platform was partly inspired by this:-

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http://www.rcts.org.uk/features/mysteryphotos/show.htm?srch=tynycwm&img=Y-26-12&serial=1

http://www.rcts.org.uk/features/mysteryphotos/show.htm?srch=tynycwm&img=Y-29-22A&serial=2

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And some other atmospheric shots, from what is a wonderful resource (RCTS 'mystery photos'):-

http://www.rcts.org.uk/features/mysteryphotos/show.htm?srch=B-64-27&img=B-64-27

http://www.rcts.org.uk/features/mysteryphotos/show.htm?srch=B-65-20&img=B-65-20

http://www.rcts.org.uk/features/mysteryphotos/show.htm?srch=caedu&img=G-101-14A

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I'll leave you to navigate around the RCTS site, and wallow !

 

Brian R

[The Stationmaster]

Right Mr Brian here it is.  But first a few notes.  This is very much the wartime resignalling job when discs would have most likely appeared as single discs instead of multiple stacked (although you could have a few of those instead of singles if you wish).  I have 'kept' some goods line signals for the Down Sidings and headshunt as I think they would be there in view of their much better sighting than discs, not also that the signal with two arms serves lines coming in from both routes into the double slip (I've done the same in the exchange sidings and just put in one disc to serve both lines) - all typically GW.  

 

The rest is fairly straightfoward although you do - prototypically - get a whole succession of discs at the point toes in the Down Main.  signal heights depend on sighting and siting constraints and I think Outer Homes are a possible on at least the Main Lines in order to keep trains on the move but they'r optional and would in any case be off-scene.  I think the most likely signalbox site is on the Down side by the sidings neck - just south of the double slip and set back  a bit to provide clear sight lines for shunting the sidings.

 

 

 

[br2975]

Diolch yn fawr Mike.

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Your help in this matter is greatly appreciated.

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Brian R

[Grovenor]

 

 - all typically GW.

Well maybe, but I hope people don't take this to imply 'exclusively GW' it was normal on the LM as well and I would suspect most other places.

Regards

Keith