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| Carmuirs Triangle Bell Codes 08/04/2010 at 13:48 #1080 | |
Danny252
1461 posts |
In last night's MP session, I started wondering about whether or not the boxes on and around the Carmuirs Triangle (assuming that's its name!) would use "Train Approaching" (1-2-1) bell codes, due to the fact that the boxes are very close to eachother. Whilst I've not found anything online, I've put together a spreadsheet of possible bell codes that, when used, would allow a train to pass through without being checked by either homes or distants, the obvious exceptions being junctions where signals have warner routes/holds. Hopefully this is relatively close to the real working, but without box instructions, I can't be sure! Also, the real working may well have checked trains, dependent on the line speeds. I've assumed that if Box A sends ILC to Box B, it is legal for Box B to send ILC to Box C immediately, due to their closeness. Any box pairs not mentioned are assumed to be normal working. Comments/real workings appreciated! File Log in to reply |
| Carmuirs Triangle Bell Codes 08/04/2010 at 13:48 #8254 | |
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Danny252
1461 posts |
In last night's MP session, I started wondering about whether or not the boxes on and around the Carmuirs Triangle (assuming that's its name!) would use "Train Approaching" (1-2-1) bell codes, due to the fact that the boxes are very close to eachother. Whilst I've not found anything online, I've put together a spreadsheet of possible bell codes that, when used, would allow a train to pass through without being checked by either homes or distants, the obvious exceptions being junctions where signals have warner routes/holds. Hopefully this is relatively close to the real working, but without box instructions, I can't be sure! Also, the real working may well have checked trains, dependent on the line speeds. I've assumed that if Box A sends ILC to Box B, it is legal for Box B to send ILC to Box C immediately, due to their closeness. Any box pairs not mentioned are assumed to be normal working. Comments/real workings appreciated! File Log in to reply |
| Carmuirs Triangle Bell Codes 08/04/2010 at 14:51 #8256 | |
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Late Turn
699 posts |
I don't know if you were intending to attach the spreadsheet to your post, but I can't see it! In general though: sending ILC forward immediately upon receipt would be a sensible alternative to the use of Train Approaching in certain circumstances (though obviously could only be used for a limited number of consecutive boxes, otherwise you'd end up with the later boxes signalling a train hours before it arrived!) - any such authority to deviate from the method of working laid down in the Rule Book would almost certainly be given in the Special Instructions for that location. I'd have thought it would be unusual for anywhere to send ILC forward immediately upon receipt, and then receive Train Approaching also - if the latter is to be used, then it'll be sent in good time to allow the train to be offered forward and the signals cleared.
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| Carmuirs Triangle Bell Codes 08/04/2010 at 14:55 #8257 | |
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Danny252
1461 posts |
Hopefully the link is there now!
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| Carmuirs Triangle Bell Codes 08/04/2010 at 15:51 #8261 | |
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Late Turn
699 posts |
That's better! Firstly, I'm not sure whether Carmuirs West actually operates AB to Greenhill, and similarly for Carmuirs East to Grangemouth. The apparent presence of automatic signals mid-section, plus the position of Greenhill Jn relative to the section, suggests TCB over both of those. Leaving that aside though, and assuming AB throughout for the benefit of interesting discussion... I'd suggest that Carmuirs East would want to offer forward and pull off before receipt of TES from Carmuirs West - either upon receipt of ILC from Carmuirs West, or upon receipt of Train Approaching if ILC would be too early. Not sure whether the overlaps shown in the sim reflect the clearing points in reality, but it looks as though accepting one from Carmuirs West might tie the junction up anyway, so there'd be little benefit in not offering forward straight away. Wouldn't have thought Grangemouth would need to offer forward immediately though - seems ample time to wait for TES, or at least authorise the use of Train Approaching from Carmuirs East (upon receipt of TES from West) and offer forward then. Similarly, for a Falkirk - Stirling train, I'd expect Larbert Jn to offer forward to Larbert North prior to receiving TES from the former. Log in to reply |
| Carmuirs Triangle Bell Codes 08/04/2010 at 16:02 #8262 | |
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Danny252
1461 posts |
For CW to CE, both CW13 and CEJ9 cannot show an aspect higher than caution (I think?) when set for this route, due to the sharp curves at the junction, so clearing through the entire section does little in terms of the aspects a train will see. For Grangemouth, I wasn't sure if there would be adequate time to send an ILC to Polmont between TES being recieved from CE and it reaching GH6, and hence a train being checked (as Grangemouth needs to offer forward to Polmont to show "Clear" at GH6). With a train going to Grangemouth docks, GH9/GH11 allow GH6 to be clear without offering the train forwards, so not as much hurry. For Larbert Jn, when a train is coming from Falkirk the first time it could be checked is at LJ24 - the last signal before Larbert North. Both CEJ15 and LJ14 will show "Clear" with a route set only to LJ24, according to Simsig at least! Edit: Also, apparently bell codes are used on track circuited block, but as advance notice only. Log in to reply |
| Carmuirs Triangle Bell Codes 08/04/2010 at 16:25 #8263 | |
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Danny252
1461 posts |
Having had a look on Google Earth, there's about 2 miles between CE and GH - so GH may indeed not need to offer forwards to Polmont until TES is sent.
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| Carmuirs Triangle Bell Codes 08/04/2010 at 16:40 #8264 | |
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Late Turn
699 posts |
CW13 and CE9 - really? I've not tried it for myself in the sim, and I don't know the area in reality, but I'd be surprised if that were the case. Approach control from red would ensure that the train's speed was reduced sufficiently, the junction indicator at those signals would indicate to the Driver the route that was set, so all that would result from holding those signals at a single yellow would be the Driver crawling round the curve unnecessarily, looking for the East's/West's (as appropriate) home signal. The simulation appears to be rather wrong as far as CEJ15 and LJ14 are concerned! Firstly, if not in a position to clear LJ24 (i.e. no Line Clear obtained from Larbert North), LJ14 (semaphore) shouldn't be cleared until the approaching train has been brought quite or nearly to a stand at it - TS1 Reg 4.6.1 applies. That's not generally applied through the locking though, but by the Signalman's application of that Regulation - the exception, in the sim, appears to be Plean Junction in the up direction, where PJ18 signal appears to require 'line clear' from Larbert North OR berth track occupied - I've come across a similar control elsewhere, but it's not widespread. Whether Simsig should simulate trains being checked in that manner (by delaying the clearance of the home and subsequent signals) is one for another day! More seriously, CEJ15 should not clear to green (Larbert Junction's branch distant controls the green aspect on CEJ15) until both LJ14 and LJ24 are also cleared - that should definitely be applied through the locking. Bell signals on TCB are used solely to advise the description of the train - normally the location of the approaching train would be determined sufficiently from track circuit occupation in the signal section(s) in rear (indicated in the advance box), but I suppose that might be supplemented by bell signals where short sections exist (e.g. between the Stafford boxes, but probably not here). Log in to reply |
| Carmuirs Triangle Bell Codes 08/04/2010 at 16:55 #8269 | |
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Danny252
1461 posts |
Firstly - by CEJ9 I meant CEJ3! Obviously a finger slipped. For CW3, I believe the rule (or at least the norm), for colour light signals, is that Caution (Yellow) is the only aspect that may be displayed with a diverging route, which explains CW13 not showing green for the diverging route. I can only assume that CEJ3 is kept at "caution" to prevent trains proceeding at high speed around the junction corner. The attached image shows these aspects (note the 2 leftmost signals are flashing). You do indeed have a point about keeping the train under control via signals if it can't be signalled through. I agree with your point about CEJ15 - assuming that it does indeed do the job of LJ's distant (which would make sense). And working on this, then yes, LJ should send ILC forwards to LN in advance. 
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| Carmuirs Triangle Bell Codes 08/04/2010 at 17:17 #8271 | |
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Late Turn
699 posts |
Not sure what the current (or indeed previous) standards say about flashing yellows approaching junctions, but it is normal for the junction signal to be held at a single yellow until the approaching train is close (sorry, forgot these were flashing yellows!). It is normally allowed to step up to the appropriate aspect as the train approaches though - the Driver's route knowledge, combined with the junction indicator confirming that he's routed around the curve, should then be sufficient to keep the train within the permissible speed. Edit: just checked back, and the issue with Larbert's down branch distant has already been reported. Log in to reply |
| Carmuirs Triangle Bell Codes 08/04/2010 at 17:32 #8272 | |
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Danny252
1461 posts |
Both signals are held at caution until a train approaches each in turn, when they return to the least restrictive aspect. Possibly Carmuirs East Jn is known to be a trouble spot with regards to speed?
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| Carmuirs Triangle Bell Codes 08/04/2010 at 17:35 #8273 | |
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Zoe
252 posts |
Late Turn said:Bell signals on TCB are used solely to advise the description of the train - normally the location of the approaching train would be determined sufficiently from track circuit occupation in the signal section(s) in rear (indicated in the advance box), but I suppose that might be supplemented by bell signals where short sections exist (e.g. between the Stafford boxes, but probably not here). Worcester Shrub Hill Station uses Train Entering Section and Train Out Of Section on the Down and Up Main to Worcester Tunnel Junction and to Henwick. Both of these are TCB with acceptance levers. Log in to reply |
| Carmuirs Triangle Bell Codes 08/04/2010 at 17:56 #8276 | |
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Late Turn
699 posts |
Danny - that's normal behaviour for the junction signal where flashing yellows are displayed in rear. Zoe - the very fact that acceptance levers are used implies that the situation at Worcester is rather different to normal double line TCB, where there's no facility to accept or refuse trains. As soon as you introduce any sort of slot or acceptance lever, in one direction or both, then you need the ability to 'offer' trains (or somehow request that the slot is given) rather than simply describing them on the bell. It follows that TES and TOOS might be necessary in connection with the operation of the acceptance levers. Can't find any reference to working single lines in such a manner in the TCB Regs (TS2) though, so I assume that it'd be covered in the Special Instructions. Log in to reply |
| Carmuirs Triangle Bell Codes 08/04/2010 at 18:01 #8278 | |
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Zoe
252 posts |
Late Turn said:so I assume that it'd be covered in the Special Instructions. Indeed it is. Log in to reply |
| Carmuirs Triangle Bell Codes 08/04/2010 at 20:54 #8287 | |
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bill_gensheet
1413 posts |
re PJ18 This has a particularly odd setup in reality. There's a timed occupancy on the approach track circuit to prevent release if the train is close. This has variously been ascribed to poor sighting or the return to use of Plean Caberboard siding. In either case it ensures that a signaller following 'pull off when the train has seen the signal at danger and is almost stopped' does not become 'driver never saw signal on and assumed the line was now clear ahead'. Bill Log in to reply |
| Carmuirs Triangle Bell Codes 08/04/2010 at 21:21 #8291 | |
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bill_gensheet
1413 posts |
Carmuirs West: Must send train description to Larbert J / Carmuirs East immediately upon receipt from Greenhill Send to Greenhill when the train reaches the pointwork at Larbert Jn or Carmuirs. Carmuirs East Must send train description to Larbert J / Carmuirs West immediately upon receipt Send to Grangemouth as soon as practicable All routes in this area are Track Circuit Block Bill Log in to reply |
| Carmuirs Triangle Bell Codes 08/04/2010 at 21:34 #8292 | |
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bill_gensheet
1413 posts |
CEJ15 aspect problem now reported. Y/G was controlled by Larbert Jn lever 15, a simple distant. Bill Log in to reply |
| Carmuirs Triangle Bell Codes 08/04/2010 at 21:45 #8293 | |
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Danny252
1461 posts |
bill_gensheet said:Carmuirs West:I'm also thinking that Larbert J should send descriptions onwards in all directions ASAP, and that Larbert N should send on to Plean ASAP a well. Log in to reply |
| Carmuirs Triangle Bell Codes 08/04/2010 at 21:55 #8294 | |
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Firefly
521 posts |
Quote:the exception, in the sim, appears to be Plean Junction in the up direction, where PJ18 signal appears to require 'line clear' from Larbert North OR berth track occupied - I've come across a similar control elsewhere, but it's not widespread. Whether Simsig should simulate trains being checked in that manner (by delaying the clearance of the home and subsequent signals) is one for another day!As Bill has stated, this control does exist at Plean and it has therefore been simulated. Quote: More seriously, CEJ15 should not clear to green (Larbert Junction's branch distant controls the green aspect on CEJ15) until both LJ14 and LJ24 are also cleared - that should definitely be applied through the locking.I agree, having just looked at the aspect sequence charts it is achieved through lever LJ15. Therefore Lambert Junction can clear LJ14 and LJ24 without CEJ15 stepping up to a Green. LJ must pull his distant lever in order for CEW15 to step up to a green. Just as you state. I'll post it on the bug board if it's not already there. Quote: For CW to CE, both CW13 and CEJ9 cannot show an aspect higher than caution (I think?) when set for this route, due to the sharp curves at the junction, so clearing through the entire section does little in terms of the aspects a train will see.CW13 can show a green if CW15 and LJ26 are both OFF. (LJ26 being LJ's distant therefore LJ25 and LJ24 also have to be OFF). CEJ3 can show a green if CEJ10 is at least a yellow however as stated it is approach released from Yellow (so it won't step Y to G until the train has passed CW13 at YY). CEJ9 is simulated as a semaphore signal. (think that may have changed now?) I've also just noticed that CEJ9 should be approach controlled if CEJ10 is showing a Red (so the same as Plean 18) Quote: All routes in this area are Track Circuit BlockWhilst it is TCB today the scheme plan that I have and that I believe the simulation is based on is as follows:- GH to CE = TCB CE to CW = TCB CE to LJ = AB CW to LJ = AB Hope this helps FF Log in to reply |
| Carmuirs Triangle Bell Codes 09/04/2010 at 09:17 #8301 | |
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Zoe
252 posts |
Firefly said:
Indeed, Larbert Junction is now closed and I believe both CE and CW work TCB to LN with train description by block bell. The sim is set in the era where both Larbert Junction and Plean Junction are open so it should be AB. Log in to reply |
| Carmuirs Triangle Bell Codes 10/04/2010 at 07:57 #8342 | |
Peter Bennet
5402 posts |
From the CURRENT working instructions in as far as it's relevant to the triangle boxes. TCB Regs apply between Greenhill, Larbert N and Grangemouth Jn; at this time Larbert Jn has been abolished but at the relevant time the area was fully TCd. In fact since the aboliton of Plean TCB now extends all the way to Stirling M. More than that I can't assist with. Peter I identify as half man half biscuit - crumbs! Log in to reply |
| Carmuirs Triangle Bell Codes 13/04/2010 at 19:55 #8472 | |
Andrew G
552 posts |
With the inclusion of Larbert Junction and Plean Junction a reasonable take on the method of working in the Carmuirs Area is: Greenhill to Carmuirs West, Carmuirs East to Grangemouth Junction and Grangemouth Junction to Polmont TCB and all others AB. Train Approaching 1-2-1 was used in the area when Swinbridge East box (between Carmuirs East and Grangemouth Junction) was still open. Carmuirs East would offer straight on to Swingbridge East and then send Train Approaching on receipt of Train Entering Section from Carmuirs West or Larbert Junction. Swingbridge East would then offer on to Grangemouth Junction. http://andrew426.fotopic.net/p55425973.html Larbert Junction would offer straight on in both directions. Carmuirs East would only offer on following receipt of Train Entering Section from Swingbridge East. For the 3 junctions Carmuirs East was the only box who could accept trains simultaneously from the other 2 junction boxes as there was a sufficient clearing point in advance of CEJ3 on the Up Branch. http://andrew426.fotopic.net/p55425999.html Log in to reply |
| Carmuirs Triangle Bell Codes 14/04/2010 at 10:15 #8490 | |
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kbarber
1742 posts |
Late Turn said:I don't know if you were intending to attach the spreadsheet to your post, but I can't see it! In general though: sending ILC forward immediately upon receipt would be a sensible alternative to the use of Train Approaching in certain circumstances (though obviously could only be used for a limited number of consecutive boxes, otherwise you'd end up with the later boxes signalling a train hours before it arrived!) - any such authority to deviate from the method of working laid down in the Rule Book would almost certainly be given in the Special Instructions for that location. I'd have thought it would be unusual for anywhere to send ILC forward immediately upon receipt, and then receive Train Approaching also - if the latter is to be used, then it'll be sent in good time to allow the train to be offered forward and the signals cleared. Sorry to come in a bit late on this. As you say, these kind of authorities (I remember them as Reg 1(e) and 1(f) - that dates me!) would be given in the Special Instructions. Everything would be set up on accordance with local conditions to ensure approaching trains could be given clear signals throughout. The 1972 Block Regs say that Train Approaching "must, where authorised, be sent in accordance with the special instructions issued"; it's possible to conceive a series of boxes offering on as soon as ILC is received, then sending Approaching forward as soon as it's received so that the last in the group gets advice pretty much as soon as the train passes the first. I believe Exeter West received Train Approaching for down WR expresses before the train was even offered, so he had very early advice and could regulate shunting etc. Not everywhere used Approach in that way. A contributor to John Hinson's Blower suggests that, on the Kings X main line, ILC would be forwarded on receipt for down expresses - sometimes for a very long distance (usually to the beginning of one of the Track Circuit Block "islands" on that line, meaning to New Barnet in the first instance). The suggestion is that, before TCB came in, boxes that held the ILC would offer forward at their discretion, using train running reports received over the single-needle telegraph that remained universal on the line until the 1970s. On the Midland Main Line, until 1978, boxes from Hendon to West Hampstead forwarded ILC on receipt. Finchley Road refused (the clearing point would be well across the Main/Suburban line junction) until the train passed Hendon, when Hendon rang the ILC code on the "overland" bell which sounded in all boxes to Finchley Road. Finchley would acknowledge with 1 beat (which didn't sound in intermediate boxes) and accept as soon as he was able (and immediately ask the road from Carlton Road Jc). All part of the fascination of old-style signalling. Log in to reply |
| Carmuirs Triangle Bell Codes 14/04/2010 at 13:26 #8499 | |
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Zoe
252 posts |
kbarber said:I believe Exeter West received Train Approaching for down WR expresses before the train was even offered, so he had very early advice and could regulate shunting etc. Exminster used a special ILC code (3-3-3) for an Up Express not due to stop at Exeter. If City Basin Junction then immediately sent Train Approaching Section to Exeter West the train would still only be in the Dawlish Warren/Starcross area. That would give quite a bit of advance notice though to Exeter West as you say though for shunting. Log in to reply |
| Carmuirs Triangle Bell Codes 29/07/2010 at 02:54 #10319 | |
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Stevie G
13 posts |
hi all i actually am a signaller from carmuirs east and can confirm CEJ 3 just works as a normal controlled signal there is actualla a banner repeater on aproach to CEJ 9 another controlled signal and CEJ 15 is the last stop signal the next signal is LN4 controlled from Larbert North
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