GW BLT - Signal Box Diagram

[Coombe Barton]

Following useful advice from RMWebbers and a blinding flash which told me what I should have been seeing all along. Any comments will be VERY welcome.

 

 

 

I've numbered levers from the up direction - is this right?

 

1 - Home

2 - Loop point and trap from loop

3 - FPL

4 - Dummy for loop

5 - Dummy for goods shed

6 - Goods yard and trap

7 - FPL

8 - Release crossover

9 - Dummy for engine release

10 - Starter

11 - Dummy from loop to main

12 - Dummy from goods yard

13 - Loco Shed

14 - Goods Yard

 

I'm postulating a fixed distant some way down the line, so there's no lever provision for that.

 

I've also been plotting movements, and this yard is going to be a right ****** to shunt. The prototype (Ashburton) used a cable (officially) to get trucks out of the warehouse line into the goods shed road, but that's not going to be possible on a model.

[Donw]

Since you going to have to use the main to shunt you should consider an outer home and advance starter so that you can use part of the main without having to block back the section.

Donw

[LNERGE]

Personally i wouldn't work 13 and 14

[ikcdab]

Following useful advice from RMWebbers and a blinding flash which told me what I should have been seeing all along. Any comments will be VERY welcome.

 

 

 

I've numbered levers from the up direction - is this right?

 

1 - Home

2 - Loop point and trap from loop

3 - FPL

4 - Dummy for loop

5 - Dummy for goods shed

6 - Goods yard and trap

7 - FPL

8 - Release crossover

9 - Dummy for engine release

10 - Starter

11 - Dummy from loop to main

12 - Dummy from goods yard

13 - Loco Shed

14 - Goods Yard

 

I'm postulating a fixed distant some way down the line, so there's no lever provision for that.

 

I've also been plotting movements, and this yard is going to be a right ****** to shunt. The prototype (Ashburton) used a cable (officially) to get trucks out of the warehouse line into the goods shed road, but that's not going to be possible on a model.

 

I don't think you need 6b as 14 would cover as the trap here - ie 14 should really be 6b.

i also have a slight issue with 13 as its a worked point but there is no signal fot it. i think that probably this might be a handworked point - ie once the locomotive was shut in, the crew could work the point by hand as they wished.

 

Hope this helps

[Coombe Barton]

Thanks, guys.

 

The prototype has no box, just a three lever ground frame and handworked points. But I'm looking at Moretonhamstead, which had a full signal box. From photos of Moretonhampstead I can't see any hand levers for that stations shed road and in goods yard point, but then neither can I see positive linklages to the signal box.

 

However I'm putting them in bacause they have to be worked somehow. Either I incorporate them into the lever frame or have some other control mechanism. So it's really which bit of the compromise I accept. It would be more convenient to incorporate them into the lever frame.

[The Stationmaster]

Getting there very nicely John. Some of what follows duplicates stuff above but some doesn't, you'll soon see which is which .

 

Essential changes -

 

Signal 1 should be co-located with discs 4 &5 (at the toe of No. 2 points).

Point numbers 2a and 2b should be transposed - the 'a' end is always that nearest the signal box.

 

Do away with trap 6b and make point 14 6b, moving the ground disc accordingly.

 

Nice To Have? -

 

Well if you have room an advanced starting signal might not be a bad idea (but it's not the end of the world) and it doesn't really offer any operational advantage except to remind a Driver shunting not to go charging off without the token.

 

Provided the points are close together Lever No.3 would quite likely be the FPL lever for both points 2b (MY 2b) and 6a.

 

I don't like -

Lever No 13 working points which should be hand points - but it is your railway after all .

 

Overall impression -

 

Great stuff, very definitely just about there. And if you can find me a GWR branch terminus with a working distant signal later than about the mid 1920s Iwill be interested to hear more - so you were spot on with that comment.

[Coombe Barton]

 

Thanks for all your replies. I think I've taken them into consideration in this latest iteration. I've renumbered from the other end - does this make more sense?

 

Levers as at present:

 

1 - Adv Starter

2 - Shunt

3 - Home

4 - FPL

5 - Main to loop and trap

6 - Main to goods

7 - Dummy main to goods

8 - Dummy main to loop

9 - Dummy loop to main

10 - Starter

11 - Dummy from goods to main

12 - Spare

13 - Engine release

14 - Dummy for engine release

 

The engine shed road is hand operated - so I'm cheating by using No. 12 Spare to do this on the model.

 

Do I have:

• The lever numbering system correct? I've tried to minimise mechanical crossing of rodding and wires from the position of the box.
• Numbers 7 and 8 as the right designations and the right way round?

I'm building the lever frame from brass with hand tools. I can't yet afford a lathe and mill. I saw the impressive frames made by Vince Worthington at ExpoEm North last yar (MRJ 193) so I'm adapring his designs using non-turned, non milled but filed working. This is probablly going to be a swearbox filling exercise.

[57xx]

...But I'm looking at Moretonhamstead, which had a full signal box. From photos of Moretonhampstead I can't see any hand levers for that stations shed road and in goods yard point, but then neither can I see positive linklages to the signal box.

Looking in Paul Karau's book, I can't see any hand levers either. The few photo's that might reveal all are frustratingly cropped just at the wrong place! I think in one though (M39), you can just see the rodding going to the goods yard point.

[The Stationmaster]

 

Thanks for all your replies. I think I've taken them into consideration in this latest iteration. I've renumbered from the other end - does this make more sense?

 

Levers as at present:

 

1 - Adv Starter

2 - Shunt

3 - Home

4 - FPL

5 - Main to loop and trap

6 - Main to goods

7 - Dummy main to goods

8 - Dummy main to loop

9 - Dummy loop to main

10 - Starter

11 - Dummy from goods to main

12 - Spare

13 - Engine release

14 - Dummy for engine release

 

The engine shed road is hand operated - so I'm cheating by using No. 12 Spare to do this on the model.

 

Do I have:

• The lever numbering system correct? I've tried to minimise mechanical crossing of rodding and wires from the position of the box.
• Numbers 7 and 8 as the right designations and the right way round?

I'm building the lever frame from brass with hand tools. I can't yet afford a lathe and mill. I saw the impressive frames made by Vince Worthington at ExpoEm North last yar (MRJ 193) so I'm adapring his designs using non-turned, non milled but filed working. This is probablly going to be a swearbox filling exercise.

 

Lever No.s 1&2 are wrong - they should follow No.10 so the pull is 10, 11 and not 10, 1.

 

I'm not too sure about the Shunt sub on (your) No.1 but if you like it (and they did look very nice B) ) stick with it and there's always a prototype somewhere (Bodmin will do for that).

 

As far as the frame is concerned drop a PM to Mick Nicholson and I'm sure he will be able to offer some good advice as his locking frame is a delight to see and work.

[Coombe Barton]

Looking in Paul Karau's book, I can't see any hand levers either. The few photo's that might reveal all are frustratingly cropped just at the wrong place! I think in one though (M39), you can just see the rodding going to the goods yard point.

 

In that book on the pix M29/M31/M32 there's only one set of rodding along the engine shed road, and this would be for the engine release crossover (M2 shows one rod and one wire for the dummy, as does M21), so the hand working of the shed point would appear to be true. However there's a strange 'line' adjacent to the shed road point visible on M38. There's no other clear pic of this in this book that I can find, and the single rodding from the box suggests that that shown is part of the hand working mechanism(?)

 

The rodding in M39 - would that be for the trap point as there's only one set? However on mine The Stationmaster has suggested a logic for working my goods yard point, which I've put in because the dimensions of mine supports this interpretation.

[Coombe Barton]

Lever No.s 1&2 are wrong - they should follow No.10 so the pull is 10, 11 and not 10, 1.

 

I'm not too sure about the Shunt sub on (your) No.1 but if you like it (and they did look very nice B) ) stick with it and there's always a prototype somewhere (Bodmin will do for that).

 

As far as the frame is concerned drop a PM to Mick Nicholson and I'm sure he will be able to offer some good advice as his locking frame is a delight to see and work.

 

Thanks for this. I'll renumber and post later (Father in Law's 83rd birthday so we're off to lunch in a bit).

 

The shunt signal is nicked from Kingsbridge, although on the outer adv starter and Brixham and St Ives with the shunt on adv starter post. Helston had a calling on arm below the adv starter.

 

And thanks for the link.

[57xx]

The rodding in M39 - would that be for the trap point as there's only one set?

Yes, I'd go with that, tallys with what's visible of the catch in M40. I'd also agree with your other comments re the single rodding, it's very obvious, unlike those pesky hand levers

 

Having said that, in M41, just below the wagon in the milage siding there appears to be a white object... One down, one to go!

[Coombe Barton]

Having said that, in M41, just below the wagon in the milage siding there appears to be a white object... One down, one to go!

Gottit!! thanks

 

Still in M41, with a good lens and a lot of faith, white artefact that may be the elusive lever against the background of the train shed. It's about 6mm up from and slightly to the left of the white spot on the back of the goods yard dummy. Much closer examination of M38 shows what may look like a lever adjacent to the stock rail. And in M1 just where the rodding for the engine release starts curving away there's a faint black vertical line that crosses (in vision) the shed point, so this could be the lever.

 

Isn't the eye of faith wonderful?

 

(for those who haven't a clue what we're on about, it's the photo numbers in Karau, P. (1978), Great Western Branch Line Terminii Volume 2. Oxford: Oxford Publishing Co.)

[57xx]

I haven't got a good lens, just my slightly ropey eyeballs, so can't see anything in M38 and M41. M1 however looks to be it though! B)

[Coombe Barton]

I haven't got a good lens, just my slightly ropey eyeballs, so can't see anything in M38 and M41. M1 however looks to be it though! B)

My 'good lens' is from a three quid set of 'helping hands' bought from a street market. I've put the lens on an optical bench because I couldn't believe how distortion free it is (and it is). Just got lucky.

 

If only I could get that lucky in the lottery!

[The Stationmaster]

Hand lever clearly visible in M1 and M38 (forgot I had the book so I've only just checked ).

[Coombe Barton]

Ok - new diagram:

 

 

and Levers:

 

1 - Home

2 - FPL

3 - Main to loop and trap

4 - Main to goods

5 - Dummy main to goods

6 - Dummy main to loop

7 - Dummy loop to main

8 - Starter

9 - Adv starter

10 - Shunt

11 - Dummy from goods to main

12 - Spare

13 - Engine release

14 - Dummy for engine release

 

And a question.

 

If shunting into the throat from the platform road, would the starter AND the shunt be pulled off? Logic says yes, as then you are controlling the whole movement. Or is it just the shunt?

 

If you are shunting from the loop or goods road then I can see these movements being controlled by the dummies 7 and 11.

 

Or would you need another dummy in the platform road for the shunt movements?

 

(And it wasn't F-in-law's 83rd birthday - it was his 84th.)

[Miss Prism]

If shunting into the throat from the platform road, would the starter AND the shunt be pulled off?

Yes.

[Coombe Barton]

Thank you. Solves a lot.

[Pannier Tank]

The Moretonhamstead Branch ( A Railway Shore to Moor) By John Owen

 

and

 

The Newton Abbot to Moretonhamstead Railway by Anthoney R. Kingdom & Mike Lang

 

both confirm that all points at Moretonhampstead except the 'Loop to Engine Shed' were controlled from the Signal Box.

[The Stationmaster]

Ok - new diagram:

 

 

And a question.

 

If shunting into the throat from the platform road, would the starter AND the shunt be pulled off? Logic says yes, as then you are controlling the whole movement. Or is it just the shunt?

 

If you are shunting from the loop or goods road then I can see these movements being controlled by the dummies 7 and 11.

 

Or would you need another dummy in the platform road for the shunt movements?

 

(And it wasn't F-in-law's 83rd birthday - it was his 84th.)

 

That's 3 questions, and congrats to F-I-L . Now your questions

 

1. The shunt ahead arm (now No.10) would only be lowered if it was necessary for the shunting movement to pass it (i.e. due to the length of the train etc being shunted).

 

2. Yes.

 

3. No - you have a signal and it can be used to control any movement even tho' it is actually a running signal. The same goes for the Home Signal (now No.1) - it would be lowered, after the movement has come to a stand at it, to admit a loco or shunt to the platform line even if that line is occupied.

[Merfyn Jones]

And 13b points would need a FPL for departing trains.

Merfyn

[Coombe Barton]

And 13b points would need a FPL for departing trains.

Merfyn

This was discussed on another thread http://www.rmweb.co.uk/community/index.php/topic/10484-gw-blt-engine-release-crossover/ that a FPL at this point is not required. There's plenty of evidence that very few of the GW release locations on BLT were provided with an FPL at this point. I agree that logically it would seem necessary, but the prototype seems to have got by without it.

[Coombe Barton]

That's 3 questions, and congrats to F-I-L . Now your questions

 

1. The shunt ahead arm (now No.10) would only be lowered if it was necessary for the shunting movement to pass it (i.e. due to the length of the train etc being shunted).

 

2. Yes.

 

3. No - you have a signal and it can be used to control any movement even tho' it is actually a running signal. The same goes for the Home Signal (now No.1) - it would be lowered, after the movement has come to a stand at it, to admit a loco or shunt to the platform line even if that line is occupied.

 

1. Becuase of the positioning of the Adv start/shunt (because of sighting) it will be frequently necessary to pass the shunt signal whilst shunting. That's the penalty of chosing this layout and not being able to cable shunt!

 

3. I can see shedloads of fun coming up if I want to run this thing correctly.

 

Thanks for all the helpful replies.

[Pannier Tank]

 

I'm building the lever frame from brass with hand tools. I can't yet afford a lathe and mill. I saw the impressive frames made by Vince Worthington at ExpoEm North last yar (MRJ 193) so I'm adapring his designs using non-turned, non milled but filed working. This is probablly going to be a swearbox filling exercise.

 

 

I've seen the MRJ Article and also the Lever Frame at ExpoEm North 2009; an excellant piece of engineering! Are you going to have an Interlocking Frame?