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| Adjacent Signal Boxes Switching Out 26/07/2015 at 10:48 #74478 | |
BoxBoyKit
166 posts |
Hi all, wondering if anyone here knows about the following. Have recently got into a discussion with some colleagues about two adjacent signal boxes switching out (specifically on a single line with ETB but guess the general question apoes anywhere). For example, A, B, C and D are all switched in. B is capable of being Switches out, as is C. The question is, is it allowed (in standards and other exciting official documents) for them both to be switched out, so you have a long section from A to D? My only opinion is that in theory it is physically possible, but only when B switches out first (creating an A-C long section). Then C could switch out as well. The opinion of a colleague is that it is not allowed to have one long section with the two intermediate boxes closes, but another says you're allowed to have either B or C switches out just not at the same Time. Hopefully that makes sense... Thoughts and comments appreciated! Log in to reply |
| Adjacent Signal Boxes Switching Out 26/07/2015 at 11:46 #74479 | |
NCC1701
129 posts |
Clearly it was permitted as you can infer from the opening and closing times of signal boxes from 1961 shown in this document for instance.
Signalman Exeter West & Llangollen Log in to reply The following user said thank you: RainbowNines |
| Adjacent Signal Boxes Switching Out 26/07/2015 at 12:19 #74480 | |
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Late Turn
699 posts |
Double line with AB rather than single line, but adjacent boxes at Quorn and Swithland are routinely both switched out, leaving a long section from Loughborough to Rothley. I can't see anything that forbids this practice in the current (or any other) Rule Book on the national network either. The only complication that I can see on an ETB or EKT single line is the multitude of instruments in different configurations that'd be required to cope with all the possible permutations of adjacent boxes switching out! In the GCR example, the boxes can and do switch out in either order, but obviously can't go through the process of switching out simultaneously. Last edited: 26/07/2015 at 12:21 by Late Turn Log in to reply |
| Adjacent Signal Boxes Switching Out 26/07/2015 at 13:33 #74482 | |
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kbarber
1743 posts |
As Late Turn says, switching out on double track is no problem and you may switch out as many boxes as you like, in whatever order you like. When I was in Junction Road we occasionally had Harringay Park out and there was one occasion Upper Holloway was out as well, so I was through to South Tottenham. Meanwhile, on the main line, I'm told numerous boxes would switch out as the end of traffic approached on Christmas Eve, until St Albans South was through to Cricklewood (5 boxes closed on the fast lines and 6 on the slow lines - Silkstream Jc, between Elstree and Hendon, didn't signal the fast lines). It's a lot more complicated on a single line because you need a unique token configuration for the long section. So if you need to be able to switch out B, C, or both, you need 3 long section tokens in addition to the short section ones. And of course the short section ones need different configurations as well. What you end up with is 5 different token configurations (short section A-B and short section C-D can both use the same configuration as there's no conflict within the same box). Boxes A and D have 3 different token machines - a short section, a medium section and a long section - while B and C also have 3 machines - 2 short section and 1 medium section. But in reality I can't conceive of such an arrangement and I don't believe any such ever existed. What you would have is a high-level decision that either B would be able to swich out or C would be able to switch out, or both would be required to switch out together. The result would need 3 different configurations. If you needed more flexibility than that, some kind of tokenless working would be required (boxes can switch out between Exeter & Salisbury, for example). Log in to reply |
| Adjacent Signal Boxes Switching Out 26/07/2015 at 15:58 #74484 | |
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bill_gensheet
1417 posts |
Various historical books quote Scottish single lines as setting up for the night (just one train north) and going home. Points set, signals off, tokens on the table ! A call to Oban in the morning to ascertain train complete and put all the tokens back in. Bill Log in to reply |
| Adjacent Signal Boxes Switching Out 26/07/2015 at 17:08 #74488 | |
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Danny252
1461 posts |
Whilst lacking in the signals off and requiring an entry in the TRB to say who picked up/set down the token, that's still a valid method of working on the SVR, and I suspect other ETB lines.
Last edited: 26/07/2015 at 17:08 by Danny252 Log in to reply |
| Adjacent Signal Boxes Switching Out 26/07/2015 at 17:14 #74490 | |
headshot119
4869 posts |
" said:Whilst lacking in the signals off and requiring an entry in the TRB to say who picked up/set down the token, that's still a valid method of working on the SVR, and I suspect other ETB lines.At Llangollen (Which is ETB) we have two "one train staffs" one covering Llangollen - Glyndyfrdwy, the other Glyndyfrdwy - Corwen East for when the other boxes are switched out. On AB it's very easy, on the North Wales Coast for example it's possible, though I don't think it happens apart from Christmas Eve for: Holywell Junction Mostyn Talacre Prestatyn Rhyl Abergele to switch out, leaving the section as Rockcliffe Hall - Llandudno Junction (Technically Colwyn Bay if the TL phone is used). "Passengers for New Lane, should be seated in the rear coach of the train " - Opinions are my own and not those of my employer Last edited: 26/07/2015 at 17:14 by headshot119 Log in to reply |
| Adjacent Signal Boxes Switching Out 26/07/2015 at 17:17 #74492 | |
KymriskaDraken
963 posts |
I've worked night shifts at Little Mill when Abergavenny and Pontrilas boxes were both swtiched out making the block section Little Mill - Tram Inn which is about 25 miles. Kev Log in to reply |
| Adjacent Signal Boxes Switching Out 26/07/2015 at 18:03 #74494 | |
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RainbowNines
272 posts |
" said:Clearly it was permitted as you can infer from the opening and closing times of signal boxes from 1961 shown in this document for instance.Fascinating document that - cheers for sharing. Log in to reply The following user said thank you: NCC1701 |
| Adjacent Signal Boxes Switching Out 26/07/2015 at 20:10 #74499 | |
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Danny252
1461 posts |
A problem that sometimes cropped up (and maybe still does) was that of getting the line voltages correct over all possible block section lengths - occasionally block bells wouldn't sound correctly if a very long block section was created without adequate additional voltage being applied. (I'm sure someone will have a story or three!) Log in to reply |
| Adjacent Signal Boxes Switching Out 27/07/2015 at 10:37 #74508 | |
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BoxBoyKit
166 posts |
Many thanks to all for the replies! Some interesting stuff 
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| Adjacent Signal Boxes Switching Out 27/07/2015 at 18:11 #74524 | |
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Ron_J
331 posts |
" said:A problem that sometimes cropped up (and maybe still does) was that of getting the line voltages correct over all possible block section lengths - occasionally block bells wouldn't sound correctly if a very long block section was created without adequate additional voltage being applied.Some boxes on the G&SW around Ayrshire used to have a "Sunday battery" which was used to boost line voltage when a whole string of boxes were switched out. Log in to reply |
| Adjacent Signal Boxes Switching Out 27/07/2015 at 18:55 #74525 | |
Andrew G
552 posts |
" said:" said:Bottom left of the picture from Hurlford is the 'Normal/Weekend' switch.A problem that sometimes cropped up (and maybe still does) was that of getting the line voltages correct over all possible block section lengths - occasionally block bells wouldn't sound correctly if a very long block section was created without adequate additional voltage being applied.Some boxes on the G&SW around Ayrshire used to have a "Sunday battery" which was used to boost line voltage when a whole string of boxes were switched out. I can also remember the one at Stevenston No 2 which was used when the box worked to Largs on Winter Sundays with Holm Junction, Hunerston and Fairlie High all switched out. Log in to reply |
| Adjacent Signal Boxes Switching Out 27/07/2015 at 18:56 #74526 | |
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Andrew G
552 posts |
" said:" said:Bottom left of the picture from Hurlford is the 'Normal/Weekend' switch.A problem that sometimes cropped up (and maybe still does) was that of getting the line voltages correct over all possible block section lengths - occasionally block bells wouldn't sound correctly if a very long block section was created without adequate additional voltage being applied.Some boxes on the G&SW around Ayrshire used to have a "Sunday battery" which was used to boost line voltage when a whole string of boxes were switched out. I can also remember the one at Stevenston No 2 which was used when the box worked to Largs on Winter Sundays with Holm Junction, Hunerston and Fairlie High all switched out. Last edited: 27/07/2015 at 18:57 by Andrew G Log in to reply |
| Adjacent Signal Boxes Switching Out 27/07/2015 at 19:00 #74527 | |
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Andrew G
552 posts |
" said:" said:Bottom left on the picture from Hurlford you can see the 'Normal/Weekend' switch.A problem that sometimes cropped up (and maybe still does) was that of getting the line voltages correct over all possible block section lengths - occasionally block bells wouldn't sound correctly if a very long block section was created without adequate additional voltage being applied.Some boxes on the G&SW around Ayrshire used to have a "Sunday battery" which was used to boost line voltage when a whole string of boxes were switched out. I can also remember the one in Stevenston No 2 which was used on Winter Sundays when working through to Largs with Holm Junction, Hunterston and Fairlie High all switched out. 
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