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Swaynton Signal Box

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Swaynton Signal Box

Unread postby Brightspark » Wed Feb 8, 2017 10:01 pm

Hello,

I am currently working on a new signal frame for Swaynton, a 4mm scale layout. At the moment there are some switches and push buttons that are generally agreed to be less that satisfactory. The layouts owner, the late Doug Smith, obtained an MSE lever frame with mechanical interlocking added on. It has done the rounds with various people trying to work out how to reuse the existing metalwork all without success and suggesting various ideas for doing it all with relays. Finally it has come to me.

I like the basic design and will emulate this in the rebuild. But first comes the problems of electrical wiring and locking charts. It is with the latter that I hope to engage your enthusiasm and knowledge in helping me find the answers to a few questions and hopefully, along the way, trying to make the model railway operation a bit more railway like.

So to start, using the guidance at the start of the forum, a description of the layout.

A signal diagram can be found in pdf format in RMweb. here http://www.rmweb.co.uk/community/index.php?/topic/116799-swaynton-for-millcliffe-on-sea/#entry2610169

The time is May/June 1960 and the location is the Southwestern main line between Southampton and Bournemouth. So it is a LSWR box with a Stevens 17 lever frame. Actually as the track layout and the current crop of signals is the same, this is Hinton Admiral but turned around the wrong way as the layout is operated from the wrong side.

And yes I am intending to have a push pull lever.

So having drawn up a locking table I have realised that I have a conflict or perhaps created a problem that isn't really there.

Question 1.
This involves the locking for signal 13 PUSH. This signal is normally used to set trains back into the Down Yard. When the signal is pulled off it locks Points 7 in either position.
I have assumed that 13 PUSH also locks out 15 & 16. Is this correct?
There is also the problem of 10, does 13 Push lock this? And what about 9?
Now if 7 is normal and 9 is reversed then is 13 Push locked? If so what happens if I want to move up to a point on the main line short of 9. Or does 9 have to be normal for safety?
Now what if 7 and 9 are reversed with an intention of movement from 13 PUSH through the yard and past 4 to the Up line? How is this interlocked to 13 PUSH?
Or
does 13 Push only lock 7?

I await your considered reply

Andy
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Re: Swaynton Signal Box

Unread postby davidwoodcock » Wed Feb 8, 2017 11:35 pm

You have made your own problem. Hinton Admiral surely only had "legally-required" dollies (ie those giving authority to pass from sidings on to a running line) and thus there was no 13-PUSH and the bobby had to give a hand signal for any shunting move other than exit ones. Nothing unusual about that.

If you want a 13-PUSH, then you have to provide dollies for the other crossovers too, you have two spare levers so making those PULL/PUSH will provide all the levers you need and it is what would have been done on the prototype in the same situation - it wasn't unusual to come across a LSWR box with no spares, that was why the PULL/PUSH levers were invented. The four extra dollies will enable every move to be signalled, you should be able to work out the locking for them without problems. Note that two of the "existing" dollies should have yellow arms, indeed any renewal of the 13-PULL dolly in the late-1950s would probably have seen it replaced with a full-size short-yellow-arm signal, there were a few dotted round the region.
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Re: Swaynton Signal Box

Unread postby Brightspark » Thu Feb 9, 2017 8:06 pm

Hi David and thanks for replying.
Perhaps I should have mentioned that Swaynton is a mix of Sway, New Milton and Hinton Admiral. Now I will confess that I didn't spot that the HA didn't have the dolly on the running line. But Sway and New Milton do. NM also has them on the Up cross-over.

The yellow dollies are an interesting thought. I was under the impression that these wouldn't be specified as there is no other route to the running line from that position. However to add to the mix, pictures of the station and yard that used to be on Steamweb (now taken down) show these to be Red/White. These images were captured later in the 60's up to electrification.

Cheers

Andy
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Re: Swaynton Signal Box

Unread postby davidwoodcock » Thu Feb 9, 2017 10:18 pm

Ah, tell half a story!

Easily accessible photos of any of these goods yards are rare, but I have found one of New Milton that definitely shows a yellow arm dolly for a movement from the yard towards the down line (crossing the up line) - it would have had to be cleared for that movement but could be passed "on" with the points set for moves towards the goods shed (as an off-topic aside comment, I hadn't noted before that New Milton had a LSWR type 1 corrugated-iron goods shed, I have now!). Given that the extension of this goods road in the London direction would have been used as a head shunt, I would certainly be surprised if there were not another yellow arm dolly there (= your 13-PULL).

In LSWR days the only dollies were almost certainly the legally required "exit sidings to running line" ones and these would all have been red flap signals. Yellow dollies only came in in the early days of the Southern (1925/6?) and, as yellow flaps were very rare, the relevant dollies would only have become yellow when the signals were renewed with Westinghouse versions (which were originally arms for both red and yellow versions, quickly - late 1920s? - becoming clipped discs for red but not until the late 1950s for yellow - as yellow on black - or, as I mentioned, full size subsidiary yellow arms).

The points for setting back from the up main into the yard were a long way from the box and I suspect that it was difficult for loco men to see hand signals from the box, so the extra disc (ie your 13-PULL) was provided to overcome this problem. The fact that discs weren't provided elsewhere in the layout suggests that this change was made in the 1930s rather than in BR days. It was quite common for PULL-PUSH levers to use the same locking for either pulling or pushing (PULL and PUSH being automatically locked against each other of course) and I strongly suspect (in the absence of locking tables) that that is what happened here, in other words 13-PULL could only be cleared for movements across the reversed points into the yard.

Normally the yard would only be worked by an up pick-up goods which would pass through the station and then set back in its entirety into the yard where it would effectively be locked in to do its shunting while other traffic passed. If a wagon in a down goods had to be shunted off, the train would stand on the down main, being split so that the wagon could be shunted across into the yard under the supervision of the bobby, the wagon being left on the goods "loop" (for subsequent pinch-baring to wherever it was required).

I hope this makes sense!

Subsequent edit:
The yellow dolly for the exit from the goods yard in the up direction wouldn't have become a full-size yellow subsidiary arm signal at Swaynton because there is an advanced starter. In the locations where they were provided they gave authority to enter the block section and were changed presumably because it was no longer (in the late 1950s) considered acceptable for a dolly to give authority to enter a block section.
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Re: Swaynton Signal Box

Unread postby davidwoodcock » Fri Feb 10, 2017 9:44 am

Although marginally off-topic, it is worth an additional comment that comparison between this line (Brockenhurst-Christchurch via Sway) and the Netley-Fareham line demonstrates clearly the effect of the 1889 Regulation of Railways Act on L&SWR signalling standards.

The Sway line opened on 6 March 1888 and the Netley-Fareham line 18 months later on 2 September 1889 but the two were under construction at the same time, the latter's opening being delayed by problems with the local geology. In the meantime, following the Armagh accident in June, the Regulation of Railways Act 1889 had been rushed through parliament (in what would normally have been the summer recess), receiving royal assent on 30 August 1889 and coming into force the same day, just a couple of days before the Netley line opened!

As can be seen, especially from Hinton Admiral, the only dollies provided on the Sway line were those that governed exit from sidings to running lines, which were required by the BoT under earlier Regulation of Railways Acts. However the 1889 Act effectively required the approval of the BoT for the totality of new signalling installations, and the L&SWR clearly decided to "play safe" as installations on the Netley line, the first to be subject to the new regulations, included a full set of dollies even though there are indications (lack of spare levers in a new box) that the original design followed the same principles as were applied on the Sway line. (The Sway line was built as double, but the Netley line as single - subsequently doubled in 1910 - nevertheless the similarities in station layout design are very obvious.)
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Re: Swaynton Signal Box

Unread postby Brightspark » Sat Feb 11, 2017 4:54 pm

Hi David,

Thanks for your further thoughts.

I am intrigued by the idea of a yellow disc. But I have not evidence of that yet. Would these be marked up differently on the signal diagrams?

I have found Nigel Kendalls photos on Flickr. These used to be on his Steamweb website.
Of interest are these photos showing the two dollies in the Down Sidings at Hinton Admiral.

For moves in the Up direction.
https://www.flickr.com/photos/billsboy/ ... 402286668/
https://www.flickr.com/photos/billsboy/ ... 402286668/

For Down release
https://www.flickr.com/photos/billsboy/ ... 402286668/
https://www.flickr.com/photos/billsboy/ ... 402286668/

I did find your explanation a bit confusing but the realised that Up and Down had got muddled. Perhaps I made a confusing remark earlier when I described turning the diagram around. To clarify the model stays the same with the platforms on the Up side of the yard. The signal box is on the up platform but the working signal box is on the other side. Because that is where we sit. You could imagine that the frame is on the back wall of the box.

Your description of the down goods is exactly how we operate. In that it always arrives on the down line and is shunted back into the down yard. It leaves only on the down line and reverses somewhere down the line before returning to Brockenhurst via Swaynton. At Swaynton it may reverse into the Up siding to allow some fast trains through.
There is some discussion about using the cross-over some more. But I could see this as placing a wagon in the Dock siding from the Down yard. There is even more reckless talk of reversing the pick up goods at Swaynton. That may mean dollies for points 11 and changing the lights on the brake van!

So to recap what is suggested is that 13 PULL and 13 PUSH will only be able to signal that 7 is reversed.
Therefore
7 Normal locks 13 PUSH & 13 PULL. 7 REVERSED can be locked by 13 PUSH or 13 PULL.
13 PUSH locked by 7 normal, released by 7 reverse and locks 7 in reverse
13 PULL locked by 7 normal, released by 7 reverse and locks 7 in reverse

Another thought. If a yellow disc is not provided, could it be that when the train was locked into the siding that the disc would be pulled off permanently until the train wished to depart?

Cheers

Andy
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Re: Swaynton Signal Box

Unread postby Brightspark » Sat Feb 11, 2017 11:28 pm

I have unearthed a picture of the ground signal for reversing back into the Down yard at New Milton my 13Push. It is red and white.
Also Sway in 1967 with all the yard pulled up except the very compact point-work and the disc signals still in place. Again red and white disc for the 13Pull. Sway had a long head shunt on the down side, so it should have yellow dollies as the shunter would have to pass them, but they don't. So does anyone have any ideas as to what is going on?

Thanks

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Re: Swaynton Signal Box

Unread postby davidwoodcock » Sun Feb 12, 2017 12:26 am

Going back to first principles.

When the L&SWR opened the line (presumably 1888) only three dollies would have been provided and these would all have been red Stevens flap dollies (green when flap down = "off"):
4 requires points 9 reversed (but 9 could only be reversed with points 10 reversed)
5 requires points 6 reversed
13 (your later 13-PULL) requires points 7 reversed
Despite being red, they would have been passed during shunting moves providing the relevant points were normal. [A few companies would have cleared the dollies for such movements but such locking tables as I have seen suggest that the L&SWR never did.] At some time in the Edwardian period*, the L&SWR started to use dollies with red arms for new works but there are virtually no clear photos of these and there doesn't seem to have been any programme to replace in-situ Stevens flaps.

This would almost certainly have remained the situation at the beginning of the Southern Railway period (and, anyway, yellow dollies did not yet exist), but parallel to the grouping process various committees had been considering proposals for "standardising" signals. Eventually UQ semaphores were one result of this process, yellow dollies were another, and, on the Southern both started to appear in the mid- to late-1920s, changes whose implementation is very difficult to date precisely from photographs. At the same time or probably a little earlier, the Southern started to use the familiar standard Westinghouse dolly, at this date with a red (with white vertical stripe) arm rather than with the later white and red cropped disc (which was in fact bolted on to the arm). Photographs suggest that there was an ongoing programme to replace the old Stevens flap discs ahead of the actual need to replace them because of wear/failures, (but in fact this programme was never quite completed, a few flaps remained until line/yard closure in the BR period). Some time in the 1930s (the earliest photo I can quickly find is 1936) the familiar cropped white/red disc appeared and these very quickly replaced the red arm (although again small numbers were missed and the odd red arm could still be found in the mid-1960s). Where dollies could be passed when "on" yellow arms began to be used instead of red ones from some time in the late-1920s, perhaps as early as 1926, but the photos you have found of Sway show that even this programme missed some locations (suggesting that some locomen's LDCs were stronger than others). Eventually, I have seen 1961 mentionned as a date but personally believe it was a few years earlier, the yellow arms started to be replaced with yellow on black discs, a programme that was certainly never completed.

On this website http://www.trainweb.org/railwest/railco/sdjr/signals.html, if you scroll down to "Ground Signals", Chris Osment has provided sketches which illustrate these basic types of signals without actually showing every variation.

Returning to your layout, I don't believe that the signal (13-PUSH) for backing into the goods yard would have been provided before the Southern Railway period, so it was probably initially a red arm, later a red on white cropped disc, Westinghouse dolly and never a Stevens flap dolly. The opposing signal (13-PULL) and also the other exit signal from the yard (4) should both have been changed to Westinghouse dollies with yellow arms (although if the substitution was early enough, they would probably have had red arms initially - they should never have had red on white cropped discs despite your photo of Sway).

The other dolly (5) would have had the initial red arm, later red on white cropped disc, Westinghouse dolly.

subsequent edit:
Stevens flap dollies were installed during the alterations at Grateley in 1901 (in anticipation of the Bulford Camp railway) but wooden posted red arm dollies were installed on the Moon Valley line which opened in 1903. The painting style of the posts on the latter was "interesting".
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Re: Swaynton Signal Box

Unread postby Brightspark » Sun Feb 12, 2017 7:26 pm

Thanks David,

I have redone my locking table and it now looks much more workable.

Occasionally I come across old railwaymen who worked the line. Perhaps one of them will recall shunting in the three stations.

When the frame is built and installed, do you think that the operators will struggle with the push-pull lever?

BTW I am intrigued by the interesting painting of posts of Meon Valley. Tell us more.

Meanwhile, with a simplified track plan and incorrect but prototypical dollies, I can ask question 2.

Question 2
Signals 3 and 14. I understand that these should only be released when the block instrument shows Line Clear.
I have assumed that points 11 also require this permission as they would require Blocking Back to use them.
Q2a Am I correct.
Q2b Has anyone tried this on a model lever frame and how did you do it?

My thinking is a point motor on a locking bar.

Andy
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Re: Swaynton Signal Box

Unread postby davidwoodcock » Sun Feb 12, 2017 10:33 pm

The pull-push lever obviously needs to be notched in some way so that it will stand at the mid-point - it's normal position - but apart from that I can't see any obvious problems for operators.

I don't know, but suspect that in 1960 that part of the Bournemouth main line still used three-wire Preece's instruments in which case there would be no connection between the operation of signals and the block instruments, it all relied on the signalman doing the job the right way (and, as Preece's were only two position, keeping his train register up-to-date). Pads of tear-off sheets BR.24847 were used in most SR boxes as a train register by this date, a carbon copy being retained by the box and the top copy sent daily to Division.

There would have been local box instructions concerning the use of crossover 11 but no physical controls. It would only have been used when it proved necessary to round a train, or, just possibly, during SLW.
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Re: Swaynton Signal Box

Unread postby davidwoodcock » Mon Feb 13, 2017 10:41 am

Having now looked at historic 25" OS maps on the Old Maps web site and also at your diagram again, I have some additional comments.

Firstly, that red dolly at New Milton is explained by the fact that the continuation there (presumably because of the nature of the cutting) was too short to be considered as a shunting neck, although it might just have been used for parking an odd engineer's wagon on occasion (which almost certainly required the dolly to be passed "on"), and the yard would have been shunted using the down road as far as the advanced starting signal. Both Hinton Admiral and Sway have continuations long enough to be used as shunting necks and would have had yellow dollies.

Only Hinton Admiral had an up siding and the continuation of that (your "dock siding") was certainly long enough to be usable (again perhaps mainly for engineer's wagons), so the dolly guarding the exit from that (your 5), at least at Hinton Admiral, would also have been yellow. Incidentally, I have considerable misgivings about that siding being a "dock siding", it certainly wasn't at any of the three prototype stations, not least because it would have been difficult to work, especially after rope-shunting was largely banned by the BoT (in the Edwardian period). The docks at all three of the prototype stations were located in the goods yard. The SA says that vehicles to be detached at all three should be marshalled at the rear of trains unless the train was a long one in the down direction when the vehicle should be marshalled at the front.

In regard to my earlier comment about SLW, on reflection I believe that SLW from the London direction would have used crossover 11, SLW from the Bounemouth direction would have used the crossover in front of the box. The use of crossover 11 would have required a handsignalman (the bobby could have done it for the one by the box) but using it would have had the advantage that a down train would arrive at the (worked) down home maximising the protection offered by the fixed signalling.

I think it would have been very unusual for a goods train to reverse direction at Swaynton (there is just nothing there to justify such a movement), but the occasional reversal of an engineer's material train would have occurred. It is also just possible that a "schooldays only" passenger train (usually around tea time) ex-Bournemouth might have reversed there.

All three of the prototype boxes had closing switches (so were probably manned for only two shifts), so Swaynton would unquestionably have had one too. (Useful on the model when you are short-staffed at lunchtime at an exhibition!)
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Re: Swaynton Signal Box

Unread postby Brightspark » Tue Feb 14, 2017 10:13 pm

Hi David,
yes I am planning a centre position. I think that some operators may struggle with this as a concept. This will either be because they are used to the usual model railway operation of "power box" type selection or they may be used to lever frames with the levers put back snugly in a neat line. It may even be that they only have knowledge of foreign railways especially the one that schedules a Great Wait at Reading, either way it will be entertaining.

An interesting thought about Preece's instruments. I had assumed that 3 position were the norm at period. But as I found out assumption is the tool of the devil.
I am wondering if there is anyone who knows for sure.
One of the questions I have saved up was about block instruments on a model railway as the requirements are slightly different to main line practice. However lets not get too far ahead.

I was also studying the length of the headshunt at the three sites using the historic maps. Yes NM and HA both seem to have a long stretch of line/siding between the points and a short siding. And yes odd wagons got parked here at those sites. So that would explain the red dolly. But then Sway has that long siding/headshunt and a red dolly. (I have a scan but cannot recall from which book).

The Up siding and dock. Yes I agree the dock is on the wrong side of the site. There is certainly no indication of such feature on the OS maps. However Doug wanted it there so there it sits. I wonder what it was intended for. The only pictures I have of the siding has a Pullman Car marked as Holiday Coach. I did suggest to our member who provided the Belle that he provides such a coach. However remarks like this do not go down well with members of the Pullman Society. Besides when the Holiday Coach was there the rest of the yard had almost gone.
On Swaynton in 1960, we find that the rails to the dock are very rusty and the dock is overgrown. I wonder if it is was ever used. There is a rumour that it was put there for the Army or Navy as part of an anti-invasion plan in the late 19th Century. (Against a French Invasion)

Reversing a goods train, yes it certainly didn't happen on the prototype. It looks like they terminated at either Boscombe or Bournemouth Goods depot. There were school trains and one service did end at NM. The empty train continued to Brockenhurst where the stock was berthed. However it did look like engineer trains did reverse at NM, but the only records are of trains doing modernisation work.

SLW we know happened during the 1960's modernisation, when the third rail was being installed. Thee are plenty of published photos and they seem to indicate that the whole section of line through the stations were run to SLW. So even then the crossover does not appear to have been used. One has to wonder at the cost benefit of installing and maintaining these crossovers as they appear to have been unused through out their whole life.

Cheers

Andy
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Re: Swaynton Signal Box

Unread postby Fast Line Floyd » Mon Mar 20, 2017 4:22 pm

One final thing, I believe you have the a and b letters of your points the wrong way round on the diagram, practice is that the a end is nearest to the signalbox. This does not make any difference to how things work it is just the convention.
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Re: Swaynton Signal Box

Unread postby Brightspark » Sun Mar 26, 2017 8:26 pm

Thanks for the tip Graham, I shall amend the master copy.

I assume that the push pull lever is the right way around. I figured that the push would be the point on the line furthest away from the signalman on the diagram.

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Re: Swaynton Signal Box

Unread postby davidwoodcock » Sun Mar 26, 2017 8:49 pm

I am reasonably certain that there isn't a convention on this, at least beyond going for the option with the simplest locking, and that would seem to be confirmed by Sway and New Milton having the "pull" and "push" the opposite way round to each other - which must have been a tad confusing to a GPR working the boxes.

I perhaps should add that it was often the case that the locking on pull and push levers was the same either way, they were obviously mutually exclusive, and in the situations where they were most commonly used - opposite direction dollies, as here, and selecting running/shunt/calling-on arms - this would normally have been the case.
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