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Author Topic: Thameslink  (Read 1329 times)
stuving
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« Reply #15 on: June 15, 2018, 03:42:06 pm »

As a mere passenger, but one familiar with some of the Thameslink core route, I've thought (ever since I found out about it) that squeezing 24tph through the likes of Farringdon was going to be a challenge. And even more so, as those trains are converging through that potential bottleneck from several different routes (if I have understood correctly)?

This is not a new nor a very demanding capacity level for two tracks. Even in 1965, in "A railway Plan for London", BR and LT gave their assumed capacities for a two-track railway as 24 tph for uniform outer suburban stock. Modern trains ought to have better performance, though less than the underground - given as 40 tph in 1965; I wonder where they achieve that now.

Merging several lines into a single track pair happens on the approach to most London Terminals, and at both sides of the central tunnel in an S-Bahn or RER system. At Waterloo, the slow lines have paths for 20 tph (vs. the fast Lines for 30), but they have to demultiplex into terminal platforms via flat junctions, rather than the simpler run through to (initially) grade-separated diverging junctions.

If you can't run the rest of your railway accurately to timetable, you will need a way of coping with that: e.g. somewhere for briefly holding trains and an acceptance that trains will run through the centre is whatever order they turn up. I reckon this is all doable, but how well it works will depend on getting a lot of details right consistently, and especially the people issues of loading and unloading enough people quickly enough. You may be sceptical about the ability of NR and one or more TOCs to do that in practice, of course.

How well any of these other networks do I 'm not sure, apart from the Paris RER tunnel between Gare du Nord and Chatelet. This has to cope with 32 tph, though that's misleading for two reasons. The first is that it's just the tunnel between two four-platform stations, with no two-platform stations in it, and the second it that it never manages that many tph. There have been plans for a while to relieve it, the latest of which was to add one more track!
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stuving
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« Reply #16 on: June 15, 2018, 04:59:27 pm »

How well any of these other networks do I 'm not sure, apart from the Paris RER tunnel between Gare du Nord and Chatelet. This has to cope with 32 tph, though that's misleading for two reasons. The first is that it's just the tunnel between two four-platform stations, with no two-platform stations in it, and the second it that it never manages that many tph. There have been plans for a while to relieve it, the latest of which was to add one more track!

I've found numbers for the RER A, which doesn't share a central tunnel. It has three west ends and two east ones, which is less that Thameslink (which also runs further out than a classic RER). It's all controlled by old-style signalling, not ATO or CBTC.

Last December, the peak "cadence" was reduced from 30 tph to 26 tph, because the load/unload times have been going up and the previous timings were no longer possible. Actually, they have spread the peak too, replacing 1 hour of 30 tph within 1h30 of 24 tph with 2h30 of 26 tph. I don't have reports of how that's been going, even on non-strike days*.

* Line A is all RATP (track and train crew) except the part branching off north at Nanterre, which is all SNCF and shares its track with St Lazare services. Line B, on the other hand, is run jointly, with RATP and SNCF drivers doing the whole route. I'm sure that makes sense to someone...
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Thatcham Crossing
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« Reply #17 on: June 15, 2018, 05:16:41 pm »

Appreciate your analysis Stuving, you've also called out a couple of the practicalities I was thinking of here....

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an acceptance that trains will run through the centre in whatever order they turn up

and

Quote
how well it works will depend on getting a lot of details right consistently

Indeed!
« Last Edit: June 16, 2018, 11:21:46 am by Thatcham Crossing » Logged
martyjon
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« Reply #18 on: June 15, 2018, 05:18:22 pm »

He's not the only one who should be considering their position.

BBC Radio 4 just had an item on this and the reporter concluded the report by saying "and many customers are saying to me that Chris Grayling ought to be the next one to follow him along the plank".
« Last Edit: June 15, 2018, 05:52:02 pm by martyjon » Logged
a-driver
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« Reply #19 on: June 15, 2018, 09:20:58 pm »

I think Charles Horton has either quit before he was pushed or been made a scapegoat with a lovely golden handshake.

NR and the DfT are not totally blameless with the situation on GTR, yet itís the M.D. of the private TOC that pays the price. This is just an attempt to appease the passenger.  Give it some time and the M.D. merry go round will be in full swing!
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bignosemac
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« Reply #20 on: June 15, 2018, 10:00:50 pm »

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grahame
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« Reply #21 on: June 16, 2018, 02:02:46 am »

I think Charles Horton has either quit before he was pushed or been made a scapegoat with a lovely golden handshake.

From a personal viewpoint, he could also be so darned fed up that he's happy to take the opportunity to move on / turn over to something different/
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martyjon
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« Reply #22 on: June 16, 2018, 05:11:14 am »

I think Charles Horton has either quit before he was pushed or been made a scapegoat with a lovely golden handshake.

NR and the DfT are not totally blameless with the situation on GTR, yet itís the M.D. of the private TOC that pays the price. This is just an attempt to appease the passenger.  Give it some time and the M.D. merry go round will be in full swing!


Things will "improve" when that Mark Hopwood fellow hears there's a vacancy for a "top dog" over at Thameslink and applies successfully, then we might see an improvement on GWR, who knows, the 17:whatsit to Hereford might even get past Oxford occasionally.
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Timmer
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« Reply #23 on: June 16, 2018, 07:08:10 am »

I think Charles Horton has either quit before he was pushed or been made a scapegoat with a lovely golden handshake.

NR and the DfT are not totally blameless with the situation on GTR, yet itís the M.D. of the private TOC that pays the price. This is just an attempt to appease the passenger.  Give it some time and the M.D. merry go round will be in full swing!
Iím sure he didnít leave empty handed and there are others who should be considering their positions too.
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« Reply #24 on: June 16, 2018, 09:12:30 am »

They should renationalise the railways straight away. That's the only way to stop this game of political football. Now then which is the emoji for 'yes I am being ironic?'

In effect GTR is a "Nationalised" company, GTR is not a franchise but a management company ie GTR are paid a fee by the DfT to run the service; all revenue, schedule 8 payments etc go direct to DfT.

BBC South Today's Transport correspondent Paul Clifton reporting that the chief executive of Govia Thameslink Railway, Charles Horton, has resigned.

I do get the feeling at times DfT aka the Government forced the hand of GTR to "break" the Guards on trains issue once and for all on Southern however this possibly lead to GTR senior managers and executive spend time resolving the strikes on this issue than on managing the integration of GN into Thameslink and ensuring they had greater preparedness for the new time table.

As far as I am aware NR delivered access to London Bridge for route training on time in Jan 18, also the route via London Bridge is only a small portion of the overall route knowledge and even the diversion via Loughborough Jcn / Elephant & Castle is a valid route to learn as it remains as a diversion route 


As a mere passenger, but one familiar with some of the Thameslink core route, I've thought (ever since I found out about it) that squeezing 24tph through the likes of Farringdon was going to be a challenge. And even more so, as those trains are converging through that potential bottleneck from several different routes (if I have understood correctly)?



The Thameslink Core was designed for a higher through put 28 tph.  Above 18 to 20 tph can only be by the use of Automatic Train Operation between Dock Jcn (MML), Belle Isle (ECML) and Blackfriars (Southeastern)

The station dwell times are those of the Tube.




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Thatcham Crossing
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« Reply #25 on: June 16, 2018, 11:26:35 am »

General feedback seems to be that it should all work fine through the central core then.

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The station dwell times are those of the Tube.

I pass through Farringdon (on the Tube) on a fairly regular basis, and the neighbouring Thameslink trains are pretty much always stationary when I arrive and depart.

Isn't this where they switch from 3rd rail to OHLE (and vice versa)?
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paul7755
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« Reply #26 on: June 16, 2018, 01:05:20 pm »

Isn't this where they switch from 3rd rail to OHLE (and vice versa)?
Normally Farringdon is the southbound change to DC, but City Thameslink is the location for northbound change to AC.  However both tracks of the section between the stations are dual electrified, this allows for various solutions in the event of a problem, eg 8 car northbound failures can still be binned into Smithfield sidings.

Effectively it is arranged so that failure to changeover can still be dealt with before a train reaches a point of no return.

Paul
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« Reply #27 on: June 16, 2018, 03:44:00 pm »

Isn't this where they switch from 3rd rail to OHLE (and vice versa)?
Normally Farringdon is the southbound change to DC, but City Thameslink is the location for northbound change to AC.  However both tracks of the section between the stations are dual electrified, this allows for various solutions in the event of a problem, eg 8 car northbound failures can still be binned into Smithfield sidings.

Effectively it is arranged so that failure to changeover can still be dealt with before a train reaches a point of no return.

Paul


That is correct, I sat on a number of the HazId and HazOp meetings for the operating and safety processes for Thameslink.


General feedback seems to be that it should all work fine through the central core then.

Quote
The station dwell times are those of the Tube.

I pass through Farringdon (on the Tube) on a fairly regular basis, and the neighbouring Thameslink trains are pretty much always stationary when I arrive and depart.

Isn't this where they switch from 3rd rail to OHLE (and vice versa)?

The transition is part of the ATO through these stations the Driver has to confirm the pan is down / up before approving the proceed for the train to close the doors and applying power
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stuving
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« Reply #28 on: June 16, 2018, 08:05:15 pm »

I had a look at the record of operations via the Thameslink core to get some real numbers; what follows is taken from RTT for last Thursday. There are times given for arrival and departure, so a dwell time can be calculated by subtraction. I don't think that will be the same as you'd get with a stopwatch if you were on the platform, but it's the best we have. If anyone knows what the differences are we could try to correct for them.

The tph each way in the six peak hours at Farringdon (City Thameslink is, obviously, almost identical) were:
North - 10/13/11 and 7/7/8, south - 12/13/13 and 8/9/9.
So nowhere near 24 tph, even in the morning when there were almost no cancellations. In the evening, it was cancellations that took the numbers down so much.

For dwell times at Farringdon, over the whole day and both ways (336 trains called), only two exceeded 2 minutes and 5 equalled that time. The rest spread over 0.5 to 1.75 minutes, with 50% being either 0.5 or 0.75. In the morning peak (7-10) only 5 of 73 dwells exceeded 1 minute, and none 2 minutes. In the evening (5-8), of only 48 dwells, just 3 were of 1.25 minutes and the rest 1 minute or less. City Thameslink has generally lower dwell times, as you'd expect.

So the dwell times are not far from what is needed for 24 tph, but even the working timetable now has far fewer than that so it's not possible to say if they could actually achieve that.
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SandTEngineer
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« Reply #29 on: June 20, 2018, 06:49:08 pm »

An interesting read: https://www.londonreconnections.com/2018/holy-grails-and-thameslink-fails-part-2-the-plan-that-went-wrong/

In particular this bit made me giggle a bit: https://cdn.londonreconnections.com/2013/Job-Application-for-CEO.png
« Last Edit: June 20, 2018, 07:15:27 pm by SandTEngineer » Logged

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