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Post by tangy on Apr 10, 2020 8:58:09 GMT
One early evening on a weekday earlier this year, I was travelling from Arnos Grove.
The first southbound train was signed from the middle platform, so walked down and boarded. About 30 seconds before the train was due off another southbound train pulled into the normal outer platform and I immediately thought the usual "What train will depart first?"
Anyway, the train I was on did depart first from the middle road but I was surprised when the train was routed to the right onto the northbound line then back across to the southbound at the # (crossover) closest to the tunnel. A move I was very pleased about as I have wanting to do the aforementioned # for ages!
So got me thinking is this standard procedure for trains to depart the middle platform at Arnos Grove when another train is in the outer platform (due to the downhill grade) or did I just stumble across this timetabled working without realising the train did this move.
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Post by superteacher on Apr 10, 2020 9:05:59 GMT
Sounds like a rusty rail move.
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Post by Dstock7080 on Apr 10, 2020 9:10:41 GMT
Two routes are available from pfm.2/3 westbound, PJ31 route 1 via 21 crossover and PJ31 route 2 via 19 crossover (nearest the tunnel)
with a train stationary in pfm.4 (proved by track circuits) it is possible to route a train from pfm.2/3 via No.21 crossover westbound
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Post by marri260 on Apr 10, 2020 12:11:20 GMT
Yes, two routes available from PJ31 as stated. No indication to the driver which route has been set, aside from observing which direction 21 crossover is set for. Fairly rare to get a route 2 over the long crossover as it is known, as this obviously blocks up the eastbound road and will cause eastbound trains to be held at PJ1 whilst the move takes place. Routing a train from the middle platform via PJ31 route 1 obviously doesn't interfere with the eastbound road at all.
The only advantage of using route 2 is that it allows a westbound train from Southgate to berth in platform 4 as normal, albeit having been drawn up on PJ320 (half way down platform 4, protecting the overlap on the platform 4 starter PJ32). Whereas if PJ31 route 1 was cleared, a westbound train from Southgate would be held just outside the platform at PJ33.
This is one of the notable changes that nobody can quite understand since the introduction of PICU - it is before my time on the Pic, but my understanding is that prior to PICU, PJ320 served to allow a train to berth into platform 4 as described, but with PJ31 route 1 clear.
Personally I find the signalling at Arnos generally quite inefficient overall - there are a number of small modifications and improvements that would be of huge benefit.
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Post by PiccNT on Apr 10, 2020 22:42:37 GMT
This is one of the notable changes that nobody can quite understand since the introduction of PICU - it is before my time on the Pic, but my understanding is that prior to PICU, PJ320 served to allow a train to berth into platform 4 as described, but with PJ31 route 1 clear. Personally I find the signalling at Arnos generally quite inefficient overall - there are a number of small modifications and improvements that would be of huge benefit. Yes, things did change when PICU was introduced into the area. PJ320 seems to be used a lot less as a draw up signal these days. If a train is going west from platform 3, the train approaching platform 4 will be held, as you say, at PJ33 or the train in P3 will be held until the train is fully berthed in P4. |
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Post by rheostar on Apr 11, 2020 9:02:39 GMT
This is one of the notable changes that nobody can quite understand since the introduction of PICU - it is before my time on the Pic, but my understanding is that prior to PICU, PJ320 served to allow a train to berth into platform 4 as described, but with PJ31 route 1 clear. That's probably not such a bad thing as there were so many SPADs at PJ320. The main reason for the SPADs is that PJ320 is low down at track side on the left hand side. Despite bigger back plates to make the signal more visible, drivers kept hitting it. |
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Post by nig on Apr 11, 2020 13:14:51 GMT
This is one of the notable changes that nobody can quite understand since the introduction of PICU - it is before my time on the Pic, but my understanding is that prior to PICU, PJ320 served to allow a train to berth into platform 4 as described, but with PJ31 route 1 clear. That's probably not such a bad thing as there were so many SPADs at PJ320. The main reason for the SPADs is that PJ320 is low down at track side on the left hand side. Despite bigger back plates to make the signal more visible, drivers kept hitting it. not as low anywore moved it higher a few years ago and now got a lit 10mph speed restriction at start of platform if it's showing red |
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North End
Beneath Newington Causeway
Posts: 1,769
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Post by North End on Apr 11, 2020 13:29:27 GMT
This is one of the notable changes that nobody can quite understand since the introduction of PICU - it is before my time on the Pic, but my understanding is that prior to PICU, PJ320 served to allow a train to berth into platform 4 as described, but with PJ31 route 1 clear. That's probably not such a bad thing as there were so many SPADs at PJ320. The main reason for the SPADs is that PJ320 is low down at track side on the left hand side. Despite bigger back plates to make the signal more visible, drivers kept hitting it. It’s possible something was put into the PICU logic to avoid drivers seeing PJ320 at danger - especially with it being known as a multi-SPAD signal. However this could be a double-edged sword as presumably the interlocking itself wouldn’t have changed, so it could still remain at danger for example if routes were being selected manually by the signalman (or even the site was being worked from the IMR for any reason). |
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Deleted
Deleted Member
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Post by Deleted on Apr 11, 2020 14:59:56 GMT
I really don’t know the site but most speed control signals which has a 0 at the end of the number do not have a lever on the frame and works automatically. There is one on the District at Earls Court EC600 has a lever.
If the signal it’s protecting is cleared the speed control will also be cleared.
PICU would of taken the original logic from the lever op board or a computer and applied it to PICU. The sites we look after at the west end of the Picc haven’t had any modification to the site apart from the release is now automatic bar Ealing Common.
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Post by PiccNT on Apr 11, 2020 18:34:53 GMT
That's probably not such a bad thing as there were so many SPADs at PJ320. The main reason for the SPADs is that PJ320 is low down at track side on the left hand side. Despite bigger back plates to make the signal more visible, drivers kept hitting it. It’s possible something was put into the PICU logic to avoid drivers seeing PJ320 at danger - especially with it being known as a multi-SPAD signal. However this could be a double-edged sword as presumably the interlocking itself wouldn’t have changed, so it could still remain at danger for example if routes were being selected manually by the signalman (or even the site was being worked from the IMR for any reason). The PICU logic that holds you at Heathrow 5 WB for a minimum of 4 minutes (unless under manual control) catches a lot of drivers out as the shunt signal is also suppressed at danger. Way up in the top 10 of multi-SPaD signals. |
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Post by rheostar on Apr 12, 2020 19:57:46 GMT
not as low anywore moved it higher a few years ago and now got a lit 10mph speed restriction at start of platform if it's showing red Showing my ignorance, I've been off the Picc for two years now. |
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