Signalling Camerton following the prototype

[Coach bogie]

 

The GW Magazine for August 1931 has a close up of Camerton platform face - masquerading as Fal Vale. The signal wires are there. Two point rods are clearly seen. The platform line is laid with outside keys, the loop with inside keys.

 

As Fal Vale, it was being used for the 1931 film production 'Ghost train'. A dean goods and three bogie coaches were run up the branch for filming. Same footage re-used later in the Arthur Askey comedy version.

 

The branch was used a second time not long afterwards for a further feature film 'Kate + ten'. This time it was a 43XX mogul, and much later of course for 'Titfield Thunderbolt'.

 

Some good excuses to run some larger locos on your layout.

 

Regards

 

Mike Wiltshire

[buffalo]

According to Maggs & Beale, a 43XX was also used in the 1931 Ghost Train. They show a photo of the train with what looks like seven mainline coaches (not sure exactly what, but probably Collett types), stopped at Camerton. Apparently it was meant to represent the Cornish Riviera Express. Additional buildings created for the film can also be seen behind the coaches. They claim two coaches and four newspaper vans behind 2381 for the ghost train itself.

 

Yes, there are some good one-off excuses to run all manner of untypical trains.

 

Nick

[wagonman]

Nick

 

I've just had a shuffle through some of my notes on the B&NSR, and I've also found my copy of Pryor's diagram for Camerton. That shows FPLs (Col Yorke would not have passed the work without them) but also the crossover at the west end set for the main line rather than the loop. Likewise the slip was set for the mainline. He also shows the point leading to the siding opposite the platform as being hand worked. I could scan and send it to you if it would help. Pryor confirms type 7D with 35 levers. He adds that it was closed 23 Feb 1938 and "all points converted to hand operation".

 

I also found notes I made from file MT6/1892/6 which referred to the "Limpley Stoke & Camerton Railway" and gave inter alia details of the materials used: apparently the line was built using S/H steel BH rail 86lb/yd held in 46lb 2 bolt chairs (it even gave the fishplate dimensions if anyone is interested) on 9' x 10" x 5" sleepers. Ballast was oolite (from the cuttings), slag and ashes. The 'six-foot' was actually 6' 6" between running lines and loops and 8' 6" between running lines and sidings. Standard post and wire (8 strand) fencing was used with 5" x 5" posts at 6' centres etc. Post and rail used on some road approaches. Probably more than you need/want to know!

 

I can confirm that the distants, or at least those at Radford and Monkton Combe, were fixed as early as 1910. According to the 1910 WTT Camerton was used to pass a passenger and a goods train at least twice a day.

 

Does anyone know when the old signal box was removed? It was still there in 1910.

 

Hope this is of use.

[buffalo]

Hi Richard,

I'd forgotten that you were another of us with interests in this area!

I've just had a shuffle through some of my notes on the B&NSR, and I've also found my copy of Pryor's diagram for Camerton. That shows FPLs (Col Yorke would not have passed the work without them) but also the crossover at the west end set for the main line rather than the loop. Likewise the slip was set for the mainline. He also shows the point leading to the siding opposite the platform as being hand worked. I could scan and send it to you if it would help. Pryor confirms type 7D with 35 levers. He adds that it was closed 23 Feb 1938 and "all points converted to hand operation".

Thanks for your kind offer, I would certainly appreciate a copy of Pryor's diagram. It's interesting that you mention the western crossover set for the main line because that's what is shown in the only photo I've seen of this end. As to the hand operated point on the middle siding, that's a case of me not seeing the wood for the trees. I've been staring at the photo of the signal with the indicator box for ages without noticing the hand lever in the foreground. I think I discounted it as the end vertical of a one of those protection rails sometimes seen in front of signal boxes, though maybe they were a later idea. Closer inspection of the photo shows a couple of boards over the mechanism at the base of the lever.

 

Now, the only problem with that is that we lose one of the 25 levers, so what was it used for? Was the trap/spur off the colliery line worked by a separate lever locked by one part of the slip? Was there a gate lock on the colliery, or a gong at the colliery or down at the goods dock? Was the point leading to either the colliery entrance or the GWR siding at top right of my diagram worked from the box? This latter I doubt because it may have been out of sight of the box. When talking about the earlier track plan, Maggs refers to whistle signals being used when an engine went up there, but that was with the earlier box west of the western bridge.

 

I also found notes I made from file MT6/1892/6 which referred to the "Limpley Stoke & Camerton Railway" and gave inter alia details of the materials used: apparently the line was built using S/H steel BH rail 86lb/yd held in 46lb 2 bolt chairs (it even gave the fishplate dimensions if anyone is interested) on 9' x 10" x 5" sleepers. Ballast was oolite (from the cuttings), slag and ashes. The 'six-foot' was actually 6' 6" between running lines and loops and 8' 6" between running lines and sidings. Standard post and wire (8 strand) fencing was used with 5" x 5" posts at 6' centres etc. Post and rail used on some road approaches. Probably more than you need/want to know!

Many, though by no means all of those figures are quoted by Maggs, including the one about fishplates, but it's good to confirm my estimate from photos of the 6' 6" separation and correct my slightly wider estimate for the running line to siding separation.

 

I can confirm that the distants, or at least those at Radford and Monkton Combe, were fixed as early as 1910. According to the 1910 WTT Camerton was used to pass a passenger and a goods train at least twice a day.

Yes, there is a photo with the fixed distant at Radford, though maps suggest the other one is half way to Dunkerton colliery halt.

 

Does anyone know when the old signal box was removed? It was still there in 1910.

Nothing certain, as you might expect, it was there in a 1910 view showing one of the first autotrains. Unfortunately, there's no sign of it in anything else.

 

Hope this is of use.

Most definitely, thanks.

 

Nick

[The Stationmaster]

I've just had a shuffle through some of my notes on the B&NSR, and I've also found my copy of Pryor's diagram for Camerton. That shows FPLs (Col Yorke would not have passed the work without them) but also the crossover at the west end set for the main line rather than the loop. Likewise the slip was set for the mainline. He also shows the point leading to the siding opposite the platform as being hand worked. I could scan and send it to you if it would help. Pryor confirms type 7D with 35 levers. He adds that it was closed 23 Feb 1938 and "all points converted to hand operation".

 

Well it might at least solve the questions about the way the slip was connected!

George was apparently known to have occasional errors in some of his diagrams (probably due to poor source information as he came up with a lot of old stuff) but I don't think his diagrams are ever anything but absolutely logical and every one I have checked against pics has been accurate in terms of equipment present etc. But one thing that should not be ruled out is that alterations did take place at even the humblest of locations so George's diagram might well differ from Clark's and both could be right (sorry about that Nick - more research).

[buffalo]

No problem Mike, for me the research is at least half of the fun.

 

Nick

[RailWest]

Sadly I have found errors in some of George Pryer's diagram which have included having the 'normal' set of points drawn the wrong way. In one case (Maiden Newton) GP's arrangement actually seemed more logical than the 'real' way!

 

"At the west end of Camerton, the three rods appear to be for the FPL and each half of the crossover. The oddity here is that Clark's diagram shows the normal setting of the facing point on the line in from Hallatrow is into the loop. Mike has suggested above that this is to provide a way of catching runaways on the gradient between Hallatrow and Camerton"

 

In all the cases of "3-lever" loop ends (ie FPL, facing point and trap all on separate levers) that I have encountered, the normal position of the facing point is for the main line. (Incidentally, the north end of Buckfastleigh loop was a good example of the trap leading to a spur/siding, although without any signal for the move.) Although the idea about gradients is not unknown, I would suggest that is such a case there might have been an additional catch point in the crossing to throw off a runaway before it entered the loop - tho' perhaps as the loop would not have been holding a passneger train there were not so bothered.

 

Somewhere - if only I could find it !! - I have the sketch which I worked out at the time of my original research and this accounted for all the levers. I'l post further if/when I find it.......

[buffalo]

Thanks to Richard, I have now seen Pryer's diagram which does confirm the normal setting of the point at the west end to be into the platform line. Otherwise, the arrangement of the slip, its associated crossing point from the loop, and the spur on the colliery line are all as in my latest attempt, though he does not give any lever numbers. I am mystified by one little symbol on his diagram, there appears to be something like an 'X' in the arrow linking the base of my signal 13 (the one with the indicator box) to the track. Can anyone explain this, please?

 

My current impression is that Pryer's diagram is a good representation of the situation after 1910 and that Clark's shows the arrangement after passenger services ceased in 1925. It's possible that the unusual 'normal' setting of the western point actually dates to after the lifting of the track from Hallatrow some time after closure of that end of the branch in Feb 1932, but before closure of the box in Feb 1938. Interestingly, a photo in the GWRJ 60 article shows this end after truncation and the point is set as per Clark.

 

As far as my proposed layout is concerned, it looks like I can follow Pryer for the 1910 plan, but we are left with the function of mystery lever. Unfortunately, I don't understand enough about the possible ways that a slip with crossovers could be operated so I'll need to keep looking. Eventually, I'll have to paint the levers in the box and it would be good to get them right or, at least, plausible.

 

Somewhere - if only I could find it !! - I have the sketch which I worked out at the time of my original research and this accounted for all the levers. I'l post further if/when I find it.......

 

Thanks, all contributions gratefully received.

 

Nick

[The Stationmaster]

Unfortunately, I don't understand enough about the possible ways that a slip with crossovers could be operated so I'll need to keep looking.

Nick

 

The pic below (I hope) illustrates three possible ways in which the slip could have been connected. I have come across enough evidence to indicate that at one time or another the GWR used all three of these methods in some way, or combination, or another.

Sketch 1 indicates the most economical method in terms of lever use (FPLs are omitted in all sketches) but it has the potential disadvantage (for some designers) that levers A & B are completely free of locking with each other although obviously they lock and release the appropriate signals which means they are also backlocked by certain signals.

Sketch 2 shows the separation of of the two 'crossovers' with a third lever working the slip connection which links them. If Lever B also works the trap then again there is no locking between A & B. However if the colliery trap is worked by Lever D another solution presents itself - and is discussed below (which might give you a hint about where things could be heading).

Sketch 3 is as much to show the way the slip roads were sometimes worked although - possibly for obvious reasons - it doesn't seem to have been all that common on the Western (I've found barely a handful of examples thus far and one is from about that time) and in the Camerton situation it would in any case be unworkable unless Lever D were introduced - at which point it starts to make some sense but involves an unnecessary number of lever movements although it offers very simple locking requirements which would have been welcome prior to the introduction of Vertical Tappet Locking; possibly some older design ideas were lurking in someone's mind at Reading?

 

Now the sketches - sorry but just a quickie job so no artistic finesse at all -

 

And now a possible solution On balance I think Lever D would have worked the colliery trap because its introduction allows a measure of locking between the various point levers which is not possible without it. In Sketch 2 + Lever D Levers A & B could now lock each other while A would release C. Either B or C would release D. It thus becomes impossible to set a number of conflicting movements which could otherwise not be locked if Lever D was not provided while the introduction of Lever C allows Levers A & B to lock each other. I am increasingly inclined to the view that in its time this level of locking might have been preferred to the much cheaper alternative offered by Sketch 1although I might be wrong.

 

On balance I think that Sketch 3 (with the addition of Lever D) is less likely to be adopted than Sketch 2 (+LeverD) as it requires two levers to be pulled to allow a train out of the loop onto the main.

 

Anyway that's my initial thought for today.

[RailWest]

"I am mystified by one little symbol on his diagram, there appears to be something like an 'X' in the arrow linking the base of my signal 13 (the one with the indicator box) to the track..."

 

Probably an asterisk, and a convention to indicate the actual position of the signal post when - for reasons of clarity - it has been necessary to draw the signal off to one side.

[buffalo]

The pic below (I hope) illustrates three possible ways in which the slip could have been connected...

Many thanks for that, Mike. I can at least now start to comprehend how the locking might work, at least from a theoretical perspective. Your sketch 1 is what I was aiming for in the latest version of my diagram where my 18 and 19 correspond with your A and B. I hadn't realised that there was a problem with locking here.

 

Now, we know that there is one lever unaccounted for because my 10 was hand operated. That allows us to have the A+B+C of your second and third sketches, but not D. Presumably, this is why you expressed concerns about the numbers of levers earlier in the thread. Looks like we need to find another lever from somewhere. Now, for some reason, I've shown the signal with indicator box as needing three for the indicator and one for the arm. I think this is a mistake as I think you said earlier that it would need three in total. So, if that is our missing lever, then we are back to the full complement of 25.

 

Probably an asterisk, and a convention to indicate the actual position of the signal post when - for reasons of clarity - it has been necessary to draw the signal off to one side.

You could well be right, thanks.

 

Nick

[The Stationmaster]

Many thanks for that, Mike. I can at least now start to comprehend how the locking might work, at least from a theoretical perspective. Your sketch 1 is what I was aiming for in the latest version of my diagram where my 18 and 19 correspond with your A and B. I hadn't realised that there was a problem with locking here.

I had certainly been thinking about it in 'modern' terms and as I say above I don't think it unlikely that it might have been considered in a different way back then - alas there's no one around now to ask and the two best experts on the history of Western interlocking rules are now dead (I'm not sure about a third who might know?).

Now, we know that there is one lever unaccounted for because my 10 was hand operated. That allows us to have the A+B+C of your second and third sketches, but not D. Presumably, this is why you expressed concerns about the numbers of levers earlier in the thread. Looks like we need to find another lever from somewhere. Now, for some reason, I've shown the signal with indicator box as needing three for the indicator and one for the arm. I think this is a mistake as I think you said earlier that it would need three in total. So, if that is our missing lever, then we are back to the full complement of 25.

Nick

The route indicator signal showing three routes would mean three levers. I'm not sure how well this will show up on the pic below (of a much more modern signal with, I suspect, a later style of route indicator but, I trust, a similar mechanism). I hope the picture is clear enough to show the several balance levers which lie beneath the 'box' at a right angle to it. These are operated, one for each route indication, by the wire from the signalbox which attaches at the end of the lever furthest away from our viewpoint. When the signalbox lever is operated the signal wire is pulled and the rear of the balance lever drops as the end this side of the pivot rises and pushes the stencil indication up into the white coloured part of the route indicator box. You can just make out the bar which goes across the top of the balance levers and it is pushed upwards when any one of them rises - the upward movement of the bar drives the downrod upwards and it operates the signal arm. Please excuse the drastic enlargement of a Tri-X pic from 1965

 

Although it is of something very different these two pics of a drop-off slot show a similar sort of principle in much greater detail (digi camera 2009 - a step change in technology). In this case the signal arm is worked by the central balance lever and in order to be able to move it requires both of the two outer levers to move so that the end where they are connected to the signal wire is pulled downwards; once they are both down the slot can 'drop-off' under the weight of its own balance lever while returning either of the others to their normal position will force the slot bar back up and return the arm to danger. In a nutshell two different control points can operate the same signal but both of them have to pull-off in order for it to clear while either of them can restore it to danger.

 

n.b. These two photographs were taken during an official IRSE visit to the South Devon Railway with the permission of that Railway.

[buffalo]

Those photos and your explanation make it very clear, Mike. What hadn't ocurred to me is that there would be no route showing unless the signal was off

 

Nick

[wagonman]

"I am mystified by one little symbol on his diagram, there appears to be something like an 'X' in the arrow linking the base of my signal 13 (the one with the indicator box) to the track..." Probably an asterisk, and a convention to indicate the actual position of the signal post when - for reasons of clarity - it has been necessary to draw the signal off to one side.

 

 

That was the way I read it.

[Miss Prism]

I'm wondering whether, in the frame, the diagram's 18 should be 19 and 19 should be 18. Might make working the slip a bit easier, and could avoid the dreaded 'reach through'? (= having to reach a lever inbetween two pulled levers)

[beast66606]

I'm wondering whether, in the frame, the diagram's 18 should be 19 and 19 should be 18. Might make working the slip a bit easier, and could avoid the dreaded 'reach through'? (= having to reach a lever inbetween two pulled levers)

 

What route are you thinking will require a reach through ?

[buffalo]

I thought we'd left the numbering of the levers as a future problem. However, the time may soon come to think about this as I've just started building signals, but so far work has concentrated on the left hand (west) end and the right hand end is still only an expanse of pink foam.

 

Nick

[Miss Prism]

Can't quite remember where my brain had got to when I was looking at the diagram (and I accept the 'lever numbering' is to be decided, although I couldn't see much wrong with the current overall strategy), but I think it was, when going from the platform to the colliery, we would have 20 in its normal pulled position, but possibly 18 might be in the pulled position as well (depending on the state of previous shunting moves), then putting 17 back to release 19, then pulling 19 inbetween the pulled 18 and 20, and then jumping back to pull 17 again (to release 11). Is that a realistic scenario, i.e. with 18 pulled???

 

I haven't been through all the other combinations, but it seemed to me that transposing 18 and 19 might make things easier. (And, indeed, giving 17 to 20 a bit more space along the frame.) Just an unformed thought at this stage really.

[beast66606]

Not sure why 20 would be reversed for a move from the platform to the colliery, it would be locking a trailing point and therefore potentially causing problems.

 

I don't see any pull between myself.

 

 

I not sure of the logic of giving 17 to 20 a bit more space, I don't recall any locking fitters ever worrying about such things.

[Miss Prism]

Not sure why 20 would be reversed for a move from the platform to the colliery, it would be locking a trailing point and therefore potentially causing problems.

 

I'm suggesting 18 & 20 could be in the reversed position as a result of a previous move, e.g. if some coal empties arrive in the platform road from Radford & Timsbury, and the loco then runs round via the loop, and then pushes the coal empties up to the colliery. In this sequence, there would be no need to return 18, and when the loco came down from the colliery, and running round the train again via the loop, 18 would still be in the right position until the loco backed down on the train for onward journey to Dunkerton.

[Grovenor]

I don't recall any locking fitters ever worrying about such things.

Not their job, the locking fitter has to build what the drawing office designed, and the drawing office did the worrying about pull betweens and where any spare levers should be left.

Keith

[Grovenor]

I am increasingly inclined to the view that in its time this level of locking might have been preferred to the much cheaper alternative offered by Sketch 1although I might be wrong.

I fail to see any benefit from introducing extra levers just so you can have locking that the simple and most common arrangement 1 has no need for. Granted that I have seen some odd examples of slip arrangements on both GW and LNW plans, but without a window into the minds of the engineers of the day its difficult to understand, in many cases, what they were intended to achieve. I would always go for the simple and obvious sketch one unless there is evidence that the specific prototype did it another way.

Keith

[Grovenor]

I'm wondering whether, in the frame, the diagram's 18 should be 19 and 19 should be 18. Might make working the slip a bit easier, and could avoid the dreaded 'reach through'? (= having to reach a lever in between two pulled levers)

I agree with your conclusion here but not necessarily with your reasons, and as Buffalo stated he did not intend these to be lever numbers. But with a simple layout like this it would be usual to have the fpl lever next to the points it locked, as it keeps things simple and there is no reason to do it any other way. So we would have the fpl for departures as 17, the crossover to the colliery as 18, the crossover to the loop as 19 and the fpl for arrivals as 20. Quite likely the lock stretcher would only be notched for normal and the fpls not used for moves over the points reverse, but Stationmaster would know the GW practice better on that one.

Keith

[beast66606]

Not their job, the locking fitter has to build what the drawing office designed, and the drawing office did the worrying about pull betweens and where any spare levers should be left.

Keith

 

The comment was not about pull betweens ...

[beast66606]

I'm suggesting 18 & 20 could be in the reversed position as a result of a previous move, e.g. if some coal empties arrive in the platform road from Radford & Timsbury, and the loco then runs round via the loop, and then pushes the coal empties up to the colliery. In this sequence, there would be no need to return 18, and when the loco came down from the colliery, and running round the train again via the loop, 18 would still be in the right position until the loco backed down on the train for onward journey to Dunkerton.

 

Mechanical signal boxes are not like power boxes, there are normal positions for levers, which generally they are returned to - Points 18 and FPL 20 would be put back to normal after the facing move had finished (whatever the numbering) as I've already said, points 18 provide flank protection for the platform line, any route signalled from there would require 18 normal,

 

I agree with your conclusion here

 

I'm surprised Keith didn't notice that simple one.