Great Western Coffee Shop

Journey by Journey => London to the Cotswolds => Topic started by: willc on August 12, 2008, 22:57:56



Title: Delays - the biggest and best
Post by: willc on August 12, 2008, 22:57:56
An interesting nugget of information in the CLPG's summer Cotswold and Malvern Line News. The chairman, Derek Potter, writing about a visit in June to an exhibition staged in Bristol by Network Rail about the Great Western RUS says there was a list of locations across the region listed in order of average reactionary delay minutes - ie where additional delays were incurred after an original delay was encountered.

In first place was Moreton-in-Marsh, with 1,094 trains delayed for 10,380 minutes (average of 9.49 mins per train).
In second place was Ascott-under-Wychwood, where 3,006 trains were delayed for 27,964 minutes (average of 9.30 mins per train).
Paddington was seventh, Evesham ninth and Oxford 11th.

Sorry, but he doesn't say over what period these counts were taken. Maybe one of the rail staff on here will know?

Nevertheless, if the ORR and DfT want more evidence of the need for more double track, I can't think of anything more compelling than this. I know some people on here have raised concerns about leaving 10 miles of single track at either end of the route, but I've always thought that the real killer of reliability and punctuality was Moreton-Evesham, where a train is instantly condemned to lose anything up to 15 minutes, once another service is occupying the section. The extra four miles or so of double track from Ascott to Charlbury will, I suspect, wipe out most of the delays there at a stroke.

The vice-chairman, John Ellis, writing about the redoubling, says that if this is signed off in October, then it now looks likely that the first stage would be Ascott-Charlbury, including a blockade at some point next year, a scenario I have heard from local staff as well.



Title: Re: Delays - the biggest and best
Post by: eightf48544 on August 13, 2008, 09:42:00

In second place was Ascott-under-Wychwood, where 3,006 trains were delayed for 27,964 minutes (average of 9.30 mins per train).
Paddington was seventh, Evesham ninth and Oxford 11th.


I can't think of anything more compelling than this. I know some people on here have raised concerns about leaving 10 miles of single track at either end of the route, but I've always thought that the real killer of reliability and punctuality was Moreton-Evesham, where a train is instantly condemned to lose anything up to 15 minutes, once another service is occupying the section. The extra four miles or so of double track from Ascott to Charlbury will, I suspect, wipe out most of the delays there at a stroke.

The vice-chairman, John Ellis, writing about the redoubling, says that if this is signed off in October, then it now looks likely that the first stage would be Ascott-Charlbury, including a blockade at some point next year, a scenario I have heard from local staff as well.



Very interesting figures. Looking at the Ascott figures it would be interesting to know what preportion were Up trains waiting for a Down train. Presumeably most as the Down trains have a clear run onto teh double track. Also the Ascott figures involve more trains.

Maybe you don't have to double all the way from Wolvercote to Ascott but I would have though a a half to a mile of double track from the junction would enable Down trains to clear the Banbury line and possibly mean an Up train could proceed from Ascott (Charlbury) to Wolvercote without having to wait for the Down train to clear the section.

Also splitting Eversham - Moreton at Honeybourne would seem a fairly easy option.


Title: Re: Delays - the biggest and best
Post by: willc on August 13, 2008, 23:52:05
Ascott delays aren't entirely up trains, because of the way the section to Moreton is signalled, or rather, not signalled.

Once you're past the home signal just inside the start of the double track, that's it in terms of block signals as far as Moreton, so if two down trains are chasing each other, eg the 17.51 to Worcester is following a badly delayed 17.21 to Hereford, it has to wait at Ascott until the 17.21 is safely inside the outer home signal at Moreton. With the 18.21 to Hereford not far behind, this can also pick up delay minutes at Ascott if this scenario arises.

There are signals between Shipton and Kingham to protect Bruern level crossing, but they do not act as block signals.

Quote
I would have though a a half to a mile of double track from the junction would enable Down trains to clear the Banbury line]I would have though a a half to a mile of double track from the junction would enable Down trains to clear the Banbury line

But as I have noted previously, Network Rail won't do this, because it would involve interfering with the signalling set-up at Oxford - due for replacement 2014-15 - cost far too much money for such a short lifespan and also make the redoubling scheme too expensive.

Hence the plan to bring the freight loops north of Oxford up to passenger standard, which would allow Cotswold trains to clear platform 2 if a delay is anticipated on the single line by moving them into the down loop, so keeping them out of the way of services heading to Banbury, but also move them part of the way to Wolvercot (the railway still uses 19th century spelling) junction. But this will involve a bit of work. I can remember a ride over this track in a Turbo a while back when the point to the main line at the north end of platform 2 had jammed. Even at low speed it was lively.


Title: Re: Delays - the biggest and best
Post by: eightf48544 on August 20, 2008, 12:12:45
Ascott delays aren't entirely up trains, because of the way the section to Moreton is signalled, or rather, not signalled.

Quote
I would have though a a half to a mile of double track from the junction would enable Down trains to clear the Banbury line]I would have though a a half to a mile of double track from the junction would enable Down trains to clear the Banbury line

But as I have noted previously, Network Rail won't do this, because it would involve interfering with the signalling set-up at Oxford - due for replacement 2014-15 - cost far too much money for such a short lifespan and also make the redoubling scheme too expensive.

Hence the plan to bring the freight loops north of Oxford up to passenger standard, which would allow Cotswold trains to clear platform 2 if a delay is anticipated on the single line by moving them into the down loop, so keeping them out of the way of services heading to Banbury, but also move them part of the way to Wolvercot (the railway still uses 19th century spelling) junction. But this will involve a bit of work. I can remember a ride over this track in a Turbo a while back when the point to the main line at the north end of platform 2 had jammed. Even at low speed it was lively.


Interesting point re down trains, therefore, it would be interesting to know the breakdown of delays between  up and down trains at Ascott.

Bringing back the freight loops into passenger service would be a help.

However, I don't think it's the cost of any new signalling required to put back a short length of double track past the juction that's holding back Netwrok rail. I think they've become scared of doing any resignalling, after their experiences with Sanbach - Crewe, Portsmouth and Basingstoke where  delays and costs have escalated.

It would seem to me that given most signalling is now modularised that the new track and signals could be installed with say a remote interlocking at Wolvercote with Wi Fi to Oxford panel. A small processor and VDU screen added to Oxford box to control the junction and the interface with Ascott and the Banbury line to its  boundary with Banbury South. The screen could then be moved to Dicot with the resignalling.  If done with modern standardised equipment Wolvercote won't then need resignalling in  2014/15.

Unless Oxford resignalling is going to use ERTMS then the fun starts.


Title: Re: Delays - the biggest and best
Post by: willc on August 20, 2008, 22:50:23
Quote
However, I don't think it's the cost of any new signalling required to put back a short length of double track past the juction that's holding back Netwrok rail.

Well, I was at the public meeting in Charlbury when Dave Ward, Network Rail's western route director, said precisely that, so who am I to doubt him? Doesn't matter how much or little track is involved, it's the sheer expense of doing anything to - or trying to interface with - the Oxford signalling kit, set against the few remaining years of life it has.

The running time beween Oxford and Wolvercot is about four minutes, so say three minutes from the goods loop if that is brought into use. In the greater scheme of things, set against the time savings from being able to run at anything up to 100mph from Charlbury to Evesham on double track all the way and the obvious reduction in delays overall that the extra double track will deliver, your suggestion just doesn't stack up, that's why it wasn't adopted. Trust me, they did extensive computer modelling of all manner of possibilities and considered their possible costs before choosing the preferred option.

What Dave Ward also said was that he regards the current proposal very much as stage one, with looking at redoubling the remaining single-line sections on the agenda when the Oxford and Worcester areas are resignalled post 2014.


Title: Re: Delays - the biggest and best
Post by: eightf48544 on August 25, 2008, 20:10:46
I am quite sure Dave Ward said what you said at the meeting.

However, the point we all need to raise is why does revamping signalling cost so much?

After all I thought the current ideas was stuff straight from the box, put together in the configuration required. Which ought to make it cheaper.

The classic case of provarication is bringing the terminal platforms at Moor Street into use. How long has that been going on? Even Chiltern with their success at redoubling, resignalling Leamington - Banbury, extra signals between Anhyo and Marylebone and Tysley layout remoddelling have not been able to crack Moor Street.

Had it been done to conicide with the refurbishment of the station, it would now be beginning to pay back any sum expended.


Title: Re: Delays - the biggest and best
Post by: willc on August 26, 2008, 12:47:20
It's not the cost of new kit itself that is the issue, it is the cost of trying to make it talk to existing ageing installations - both at Oxford and Birmingham.



This page is printed from the "Coffee Shop" forum at http://gwr.passenger.chat which is provided by a customer of Great Western Railway. Views expressed are those of the individual posters concerned. Visit www.gwr.com for the official Great Western Railway website. Please contact the administrators of this site if you feel that content provided contravenes our posting rules ( see http://railcustomer.info/1761 ). The forum is hosted by Well House Consultants - http://www.wellho.net