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| Overlaps at Exeter St Davids 30/08/2011 at 11:24 #20380 | |
Louis
32 posts |
Hi Everyone, Just questioning the signal overlaps at Exeter St Davids, yesterday while at Exeter St Davids I noticed that a train could arrive on Platform 1 and 3 at the same time one from Central and one from Barnstaple, presumeably the overlap when a train arrives from Exeter Central or Exeter St Thomas, to signals 337 and 437 does not extend over the points as it does on SimSig, would anyone be able to confirm this? This also leads onto my next point, if the overlap on these platforms does not extend over the points, then surely signal number 35 will hold at Red under approach locking, for all platforms except 5, so also this could mean that the overlap when routing to platform 6 would not go over the points? Secondly surely this applys in the opposite direction to signal 56 when routes are set to all but platform 4, and then this would affect the overlap locking the points beyond platform 3, 5 and 6 in the down direction. Would anyone be able to confirm how the overlap at Exeter St Davids works, as this would allow much more flexiblity in the event of delays possiblity like in the real Exeter Panel box. Log in to reply |
| Re: Overlaps at Exeter St Davids 30/08/2011 at 14:19 #20382 | |
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Albert
1313 posts |
Perhaps there is a warner route to enter Platform 3 in real life.
AJP in games Log in to reply |
| Re: Overlaps at Exeter St Davids 30/08/2011 at 14:28 #20383 | |
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lpeters
160 posts |
I don't have all the infomation on this but a multitude of possibilities are possible. 1) The Line speed may have been reduced since the data for SimSig Exeter was gathered and therefore the track circuiting may have been re-worked to reduce the overlap. 2) There may have been signal failures/points failures/TC failures and the signaller talked to the train from Barnstaple through without adhering to the overlaps on the panel. Everyone makes mistakes of course. 3) May have had some changes to the signalling procedures allowing warner routes in from Centre to keep the overlap clear at the Barnstaple end. As I said, there are many possibilities and they could have all happened after the Exeter sim was created. Last edited: 30/08/2011 at 14:29 by lpeters Log in to reply |
| Re: Overlaps at Exeter St Davids 30/08/2011 at 14:36 #20384 | |
headshot119
4869 posts |
Where both trains in service? If not it is possible that the one from the Central end came in on the shunt signal which doesn't cause an overlap. In fact thinking about it, a train coming from Central is most likely going towards Newton Abbot after it arrives, so is likely to "call on" on top of something already in platform 3, which would mean no overlap over the points. Allowing a Barnstaple train to arrive into one. Source "Seen it in real life" "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: 30/08/2011 at 14:39 by headshot119 Log in to reply |
| Re: Overlaps at Exeter St Davids 30/08/2011 at 15:42 #20392 | |
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Louis
32 posts |
Both trains were in service, one was an Exmouth - Paignton service and the other was a Barnstaple - Exeter Central service. Its not possible to do calling on routes from Central as it is not possible to be stopped at signal 335, Signal 335 must be showing a proceed aspect before signal 312 at Central will clear (its only a 2-aspect signal)
Last edited: 30/08/2011 at 15:42 by Louis Log in to reply |
| Re: Overlaps at Exeter St Davids 30/08/2011 at 15:47 #20393 | |
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Conner
6 posts |
" said:
That wouldn't be possible as the overlap of the train from Central would lock the points out of Platform 3 preventing them being changed to allow the Barnstaple train in to Platform 1. Log in to reply The following user said thank you: Louis |
| Re: Overlaps at Exeter St Davids 30/08/2011 at 15:59 #20395 | |
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Sam Tugwell
493 posts |
Acutally, after talking to Tristan (my cousin who did work experience at the panel), Louis has a point. According to him, the overlaps are wrong, enabling the situation that Louis saw to be possible. Tugz "Signalman Exeter" Log in to reply |
| Re: Overlaps at Exeter St Davids 30/08/2011 at 16:11 #20397 | |
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headshot119
4869 posts |
One for someone who knows more than I do about signaling. What is the point of having an overlap there to stop the points moving, as the crossing can be in the raised position. So if you did overrun I think the points would be the last of your worries.
"Passengers for New Lane, should be seated in the rear coach of the train " - Opinions are my own and not those of my employer Log in to reply |
| Re: Overlaps at Exeter St Davids 30/08/2011 at 17:05 #20400 | |
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Late Turn
696 posts 
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Level crossings have never generally been considered an obstruction within an overlap; just taking the first example that comes to mind, Thorpe Culvert (on the Skegness branch proper) could and almost always would (pre-resignalling!) accept a train from Wainfleet despite the level crossing being only yards beyond the home signal. Obviously the clearing point extended well beyond the level crossing. That said, I can think of some other locations - mechanically signalled - where the second signal in rear of the crossing couldn't be cleared until the crossing had been closed to road traffic. Signal positioning has started to take account of level crossings over (fairly) recent years though - see examples of platforms where a signal protecting a crossing is now located midway down the platform, or even in rear of the platform. Log in to reply |
| Re: Overlaps at Exeter St Davids 05/09/2011 at 19:16 #20628 | |
Peter Bennet
5362 posts |
From Danny Scroggins site I think the O/L marker is there so I've added it for the future. Looks like the south end maybe a bit different too but not materially so. One day I'll go through it with a fine tooth-comb. Peter I identify as half man half biscuit - crumbs! Log in to reply |
