Coombe Barton Signalling

[Coombe Barton]

Would any signalling maestros here mind commenting on the GW signal plans for Coombe Barton on the blog here - http://www.rmweb.co....the-signalling/

 

It's only one ground signal more than that at Moretonhampstead (the track plan is very, very close to Ashburton) and a signal box is postulated.

 

I know that I can make working ground signals, so that isn't really a problem, it's just their extent and positioning.

 

And just on a forum procedural point (pun), would you prefer that I post the whole thing here or just the link?

[The Stationmaster]

Would any signalling maestros here mind commenting on the GW signal plans for Coombe Barton on the blog here - http://www.rmweb.co....the-signalling/

 

It's only one ground signal more than that at Moretonhampstead (the track plan is very, very close to Ashburton) and a signal box is postulated.

 

I know that I can make working ground signals, so that isn't really a problem, it's just their extent and positioning.

 

And just on a forum procedural point (pun), would you prefer that I post the whole thing here or just the link?

 

 

I'd prefer it here as my head can't really get around these blog things, the old-fashioned thread thingy is about my mark

 

First it does look a bit oversignalled but that might be due to the compression of distances but more importantly the signalbox is not well placed - it needs to be near the heart of the pointwork by the station throat as that gives the Signalman a better view and saves money on ground connections.

 

The running signals are ok (it would be a fixed distant in any case, this is the GWR we're talking about!) but the Home Signal needs to be right up to the toe of the first facing point. And ideally I would suggest a double disc at the foot of it because otherwise you are introducing a lot of locking complications in a period (I'm not sure what yours is?) when the 'box would quite likely still have had a frame with twist or stud locking.

 

By the way the second incoming facer should be as close as possible to the first one to minimise risk without introducing excessively long locking bars.

 

The disc at the engine release points would fairly likely be worked off the points and still be a rotating lamp with small red & green targets - such things survived in a few places until the early 1960s. Also - although it probably has no modelling impact - those points are likely not to have a facing point lock so technically the rear end of any departing passenger train should be clear of them (a rule which was often observed in the breach).

[Coombe Barton]

Mike

 

Thanks for this. The second attempt is attached.

 

I've moved the signal box to adjoining the engine shed (prototype Moretonhampstead) and one disc signal to a double but left the home where it was at the moment. Moretonhampstead has the home right by the toe of the first turnout but Ashburton has its home a little way down the line. Wondering if this had anything to do with Moretonhampstead having a signal box but Ashburton a ground frame. The engne release at Moretonhampstead was a disc signal, so that's the prototype there.

 

Here's the new diagram:

 

[The Stationmaster]

Mike

 

Thanks for this. The second attempt is attached.

 

I've moved the signal box to adjoining the engine shed (prototype Moretonhampstead) and one disc signal to a double but left the home where it was at the moment. Moretonhampstead has the home right by the toe of the first turnout but Ashburton has its home a little way down the line. Wondering if this had anything to do with Moretonhampstead having a signal box but Ashburton a ground frame. The engne release at Moretonhampstead was a disc signal, so that's the prototype there.

 

Here's the new diagram:

 

 

That's ok apart from the Home Signal which if worked from a signal box should be as close as possible to the toe of the points to minimise the length of the locking bar (or in your case have the signal at the point toe and the locking bar within the points - often done that way by the GWR as it saved having split locking bars). In the case of the ground frame there would be no need for the locking bar as the points would only ever be moved when the frame was unlocked (and it would always be locked for a passenger train movement) so no need to have the signal close to the point toe although that would still often be the case.

 

The situation with signals at engine release crossovers did vary so you can do it whichever way you prefer - either would be accurate.

 

Moretonhampstead sgnalbox was a fascinating arrangement so that's a good idea. You could also create something else from Moretonhampstead of course and have the connection to the goods shed coming off the run round loop and crossing the line into the platform with a diamond crossing. Such an arrangement was typical of the broad gauge era and survived in a few places past gradual layout renewal and updating from the 1930s - it was of course part of the mantra of avoiding facing points.

[Coombe Barton]

Unfortunately I don't have room for a Moretonhampstead type arrangement, although it would then remove the requirement for one ground signal. I'm now incorporating your suggestions in my main blog. Many thanks.

[Pannier Tank]

Mike,

 

As BR (W) BLT's are my thing and propose something along the lines of Moretonhampstead can you please if the box would have Block Instruments and how many. I presume, one Up and one Down?

[The Stationmaster]

Mike,

 

As BR (W) BLT's are my thing and propose something along the lines of Moretonhampstead can you please if the box would have Block Instruments and how many. I presume, one Up and one Down?

 

 

David if you are going along the lines of Moretonhampstead(ish) that suggests to me you are going to have a single line? If that is the case you will either have a Electric Train Staff instrument (not over common on the GWR by the 1930s but they did have them) or an Electric Token instrument (the GWR preference post c.1912 and gradually - but never completely - spread over single lines not worked by lesser systems such as Train Staff & Ticket).

 

The Springside signalbox detailing kit (if it is still sold under that name?) includes an Electric Token (ETT) instrument and you would need only one at a terminus - painted red. lined black. I can't find a pic offhand but I must have one somewhere I'm sure.

[Pannier Tank]

David if you are going along the lines of Moretonhampstead(ish) that suggests to me you are going to have a single line? If that is the case you will either have a Electric Train Staff instrument (not over common on the GWR by the 1930s but they did have them) or an Electric Token instrument (the GWR preference post c.1912 and gradually - but never completely - spread over single lines not worked by lesser systems such as Train Staff & Ticket).

 

 

Mike,

 

My proposed layout would indeed be a single line branch line terminous. I presume the Bell Codes would still be used to describe the type of train (Passenger / Goods) etc? I will have to read up a bit more on the signalling equipment.

 

The reason for asking about the Block Instruments is that I have inherited (from my late father) a pair of LMS / BR(M) Block Instruments and wonderd if / how I could incorporate then within the layout. Oh well, I guess they'll have to remain a static exhibit .

 

Sorry for hijacking the thread.

[The Stationmaster]

Mike,

 

My proposed layout would indeed be a single line branch line terminous. I presume the Bell Codes would still be used to describe the type of train (Passenger / Goods) etc? I will have to read up a bit more on the signalling equipment.

 

The reason for asking about the Block Instruments is that I have inherited (from my late father) a pair of LMS / BR(M) Block Instruments and wonderd if / how I could incorporate then within the layout. Oh well, I guess they'll have to remain a static exhibit .

 

Sorry for hijacking the thread.

 

 

David, sorry but I slightly misunderstood what you were getting at. What you use to operate your railway and what is protypically correct to have in your model signalbox (and the method of working) are two not necessarily related things If you want to use a pair of block instruments you use 'em (are they actually LMS or are they 'Triang blocks' as the 'orrible black & white plastic BR LMR things are often known?).

 

All you need to remember about using double line instruments in your setting is that they signal Up & Down TRAINS, not separate Up & Down LINES. And in fact using double line block instruments on a single line can be quite prototypical as normal double line instruments were sometimes used on single lines worked under Train Staff & Ticket Regulations, especially post 1930sish.

 

So yes - go ahead and use them and at least if they are LMS instruments (or even more so if they are LMR Triang/plastic penguin instruments) the bells won't make too much noise - not at all like using proper Great Western bells .

 

Bell codes do differ for some of the fancier twiddly-bits of block signalling on single lines but the codes for trains are exactly the as are all the basic things like 'Call Attention'' and 'Train Out of Section' etc. Happier now?

[Pannier Tank]

Apologies (again) John for hijacking your thread.

 

Mike,

 

Sorry I didn't make it clear in my previous posting.

 

So if I were to use Block Instruments I would need two, one for up and one for down trains on a single line. I guess when looking at Signal Interlocking I need to take the single line token into consideration. I would obviously need a little modellers licence in using ex BR (M) equipment on BR (W) Region

 

The Block Instruments are probably ex LMS / BR(M) (Tall Wooden units) that were taken out of use at Bletchley in 1965 when the WCML was modernised, they are not the more modern plastic type.

[The Stationmaster]

Apologies (again) John for hijacking your thread.

 

Mike,

 

Sorry I didn't make it clear in my previous posting.

 

So if I were to use Block Instruments I would need two, one for up and one for down trains on a single line. I guess when looking at Signal Interlocking I need to take the single line token into consideration. I would obviously need a little modellers licence in using ex BR (M) equipment on BR (W) Region

 

The Block Instruments are probably ex LMS / BR(M) (Tall Wooden units) that were taken out of use at Bletchley in 1965 when the WCML was modernised, they are not the more modern plastic type.

 

 

Well at least you got the better sort of kit B)

 

If you are going into signal interlocking (brave chap that you are ) then involving the block instruments should be relatively simple although you would need to provide an electric lever lock on at least one signal. Depending on period modelled (if you are going to be super authentic with any interlocking) you might need to lock more than one signal with the block as things changed quite a bit post-war both for signalling provision and locking controls.

 

Basically the two block instruments will provide six 'states' (or 'conditions') - 3 'up' and 3 'down' - between them and of those six only one will release the signal(s) with an electric lock and all the others will, in some way or other (in terms of conditionality), lock it (them) - so the basic logic should be very easy to grasp I think.

[Coombe Barton]

No one's hijacking anything. I'm following.

 

The only layout I've ever experienced with full block working was Teddy Boston's Olton Prior. That did not have signalling, though.

 

Was the Triang nicknamed after the stuff that Traing produced in the 1960s? A net search reveals RT268 - Bell signal set (Block instruments). Another site says they were produced from 64 to 67.

 

http://www.modeltrai...asp?articleid=1

[The Stationmaster]

No one's hijacking anything. I'm following.

 

The only layout I've ever experienced with full block working was Teddy Boston's Olton Prior. That did not have signalling, though.

 

Was the Triang nicknamed after the stuff that Traing produced in the 1960s? A net search reveals RT268 - Bell signal set (Block instruments). Another site says they were produced from 64 to 67.

 

http://www.modeltrai...asp?articleid=1

 

 

Those are they John. It doesn't look much like it (sorry can't scan a pic at present) but because the LMR design was plastic and seen by many as cheap and nasty with bits inclined to drop off one of the nicnames it acquired was 'Triang' (although bearing in mind its intended purpose the Triang one was probably much better suited to its job than the LMR one was to its )