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Journey by Journey => London to Kennet Valley => Topic started by: Oxonhutch on April 05, 2017, 13:02:28



Title: Oxford Road and Southcote Junctions Grade Seperation
Post by: Oxonhutch on April 05, 2017, 13:02:28
I have been pondering this one for a while now and recognise that these two junctions are a linked pair.  Any solution will best address the issues of grade separation at both localities. The necessary engineering will not be cheap, but shouldn’t be too horrendous.  It is not Crossrail or Heathrow 3rd runway – more the scale of Airport Junction as it now stands.

A glance at the service pattern of the slow-moving freights shows a simple cross-over with stone trains passing from Westbury though Reading (and reverse) and Freightliners, car-trains etc. passing from Tilehurst through Basingstoke (and reverse). West-country HSTs and Bedwyn locals parallel the stone trains.  The only non-crossing traffic are the Cross Countries and Basingstoke locals.  The Class 2 locals call at Reading West and terminate/originate at Reading. Currently, three Class 1 semi-fasts call in the up direction in the morning rush.

The proposed layout is essentially an elongated cross over with a grade-separated route for the Basingstoke to Reading traffic.  It requires a vertical separation  along a box-like structure within the Bath Road cutting where curtain walls will accommodate the Up and Down Feeder lines within the existing footprint of the railway.

Relative elevations are shown on the diagram using colours: grey for the existing elevation, blue above, and orange below.  It is proposed that the box structure be sunk in the existing cutting as far as geology and gradients will allow. Bath Road is a relatively high crossing. Tilehurst Road might present a challenge and may require raising slightly or the box formation sinking further down than indicated to accommodate the clearance.

Land take will be required in the Oxford Road area to accommodate the four-tracking required to push the grade separation into the cutting to the south, and avoid vertical conflicts with the new Reading Viaduct and complex rail geography to the north. I envisage the land take being to the west of the existing railway and incorporating the current Up Platform of Reading West Station. This will require a new entrance to the east of the railway.

Flat crossing conflicts continue for some traffic flows, but these are minimal in the overall scheme of things.  Up Reading West traffic currently crosses over to the down lines before terminating in Platforms 1, 2 or 3 at Reading.  I propose moving this cross-over further south to Southcote North Junction in the case of Newbury locals and Southcote South Junction in the case of Basingstoke locals. Reading West would become a single bi-directional platform.  Timetabling conflicts might reduce its current service pattern or require doubling back via Reading. Rare traffic from Tilehurst to Westbury (engineers trains and possible charters) will utilise a single lead cross-over at Oxford Road Junction.

The civils required here are reasonably straight forward; the big challenge is to build this while continuing to run a railway. Over to you, planners…

Sometimes, you’ve got to be bold!

Shortened the title in light of GtBE's comments


Title: Re: Oxford Road and Southcote Junctions Grade Seperation – More Crayonista
Post by: Gordon the Blue Engine on April 05, 2017, 18:28:39
Well it's very imaginative, but sorry I don't think it's as do-able as your excellent Didcot East proposal.   Land take around Reading West would be difficult, gradients may be a problem, and a lot of groundworks (and a new bridge over the Oxford Road) would be needed to provide extra width for 4 tracks.

So its a No from me.

PS When I initially tried to post this I got an error message saying the Subject was too long, must be 80 characters or less. So I've shortened it.  Don't know how Oxonhutch managed it!


Title: Re: Oxford Road and Southcote Junctions Grade Seperation – More Crayonista
Post by: grahame on April 05, 2017, 18:36:41
PS When I initially tried to post this I got an error message saying the Subject was too long, must be 80 characters or less. So I've shortened it.  Don't know how Oxonhutch managed it![/i]

The extra 4 characters R-e-:-space can tip the balance!


Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: Adelante_CCT on April 05, 2017, 19:10:04
Agree with GTBE, imaginative but certainly not do-able, also any service stopping at Reading West towards Reading would conflict with virtually all passenger train movements departing Reading.

I have often pondered over various solutions for this area and still haven't thought of a practical solution that ticks all the boxes. Putting a grade separate junction at Southcote by having the Up Basingstoke dive under/over the Down Westbury would be the easiest option and would eliminate all of the conflicting movements across this junction, it just doesn't help with the Oxford Rd Junc side of things.

I believe a 3rd track could fit into the area, though this would require the re-positioning of Reading West station/turning it into an island platform and of course a wider deck over the Oxford Road.


Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: Oxonhutch on April 05, 2017, 19:25:33
Agree with GTBE, imaginative but certainly not do-able, also any service stopping at Reading West towards Reading would conflict with virtually all passenger train movements departing Reading.

Not really. All the up locals cross the down traffic now to access Platforms 1 to 3 to terminate.  This just moves that cross-over country side and in the case of the Basingstokes, clear of the Newbury traffic.  The Reading-Westbury lines and Down Basingstoke Feeder are bi-directional.

It is the naming of the Up and Down Westburys between Oxford Road Junction and Reading that is slightly misleading. The Up Westbury is mainly used by down traffic from Platforms 7 and 8. Up traffic mostly uses the Main Feeder under Reading Viaduct to access Platforms 10 and 11 (and also 12). The Down Westbury is mainly a bi-directional single line to/from Platforms 1 to 3.  The same today as it is on this diagram.

Platform numbers as per Stuving's comments


Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: John R on April 05, 2017, 20:26:26
It occurs to me that the removal of the Southampton - Midlands intermodal services would solve a lot of the problem at lesser expense.  It's probably too late now given the route has been gauge enhanced and the grade separation at Reading carried out, but in hindsight would it have been better to have routed services via Westbury and Swindon.  The route as far as Westbury is much more lightly used than the one up to Basingstoke, dualling part or all of the Melksham line would have been a lot simpler, and there's much less freight on the main line west of Didcot since the coal traffic ceased.



Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: stuving on April 05, 2017, 23:10:49
Agree with GTBE, imaginative but certainly not do-able, also any service stopping at Reading West towards Reading would conflict with virtually all passenger train movements departing Reading.

Not really. All the up locals cross the down traffic now to access Platforms 1 to 3 to terminate.  This just moves that cross-over country side and in the case of the Basingstokes, clear of the Newbury traffic.  The Reading-Westbury lines and Down Basingstoke Feeder are bi-directional.

It is the naming of the Up and Down Westburys between Oxford Road Junction and Reading that is slightly misleading. The Up Westbury is mainly used by down traffic from Platforms 8 and 9. Up traffic mostly uses the Main Feeder under Reading Viaduct to access Platforms 10 and 11 (and also 12). The Down Westbury is mainly a bi-directional single line to/from Platforms 1 to 3.  The same today as it is on this diagram.

Are you sure the Westburies are bidirectional all the way to Oxford Road? They weren't two years ago, and I don't think that's been changed. And as for movements from P9 - no, there's no route to the Westburies, not even via the Feeder Lines.


Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: stuving on April 05, 2017, 23:22:19
Agree with GTBE, imaginative but certainly not do-able, also any service stopping at Reading West towards Reading would conflict with virtually all passenger train movements departing Reading.

I have often pondered over various solutions for this area and still haven't thought of a practical solution that ticks all the boxes. Putting a grade separate junction at Southcote by having the Up Basingstoke dive under/over the Down Westbury would be the easiest option and would eliminate all of the conflicting movements across this junction, it just doesn't help with the Oxford Rd Junc side of things.

I believe a 3rd track could fit into the area, though this would require the re-positioning of Reading West station/turning it into an island platform and of course a wider deck over the Oxford Road.

That is, essentially, Network Rail's best idea too. It does look as if a third track would fit within railway land, or very nearly, if Reading West station is disposable. Whether three tracks would do the job is another matter. I see the approach as being to sort trains according to their route to the north using the grade separation at the south end, so you need enough track capacity for those two or three streams to cover the distance in between without conflicts. You don't need three pairs for that, but only three looks a bit cramped.

NR's proposal ends with the thought that someone should find a site for a replacement station. The obvious question to start with is why? The current station was built mainly for trains that used the West Curve and never went to Reading General, and is less than a mile away from it. So who uses it, or rather to go where - London or Basingstoke? (I presume not Reading.) Would they be better served by a station further south, or else they would be as quick to walk to Reading anyway?


Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: 4064ReadingAbbey on April 05, 2017, 23:46:39
Interesting thoughts!

As I see it a major point of conflict is that the Southampton - Midlands container trains cross the paths of everything running on the Reading - Newbury axis. These container trains run about once an hour in each direction and are quite long. If a re-routing via Westbury and Swindon as suggested by John R is not possible I wonder if a simpler solution at Southcote Junction than that suggested by Oxenhutch may be easier to build.

I would propose building a flyover to take a new single track 'avoiding line' starting between the Up and Down Basingstoke lines south of Southcote Junction, flying over the Westburys at Southcote and running along the west side of the formation through the cutting. It would continue over a widened bridge over Oxford Road - making Reading West Up platform an island - to the Reading West Curve which it would join after the Feeder Lines have diverged to the east through their diveunders. Thus northbound container trains from Southampton would have no point of contact with any other traffic until Reading West Junction on the Relief lines. Southbound trains would run onto this 'avoiding line' before they met any traffic on the lines through Reading West and join the southbound line to Basingstoke after Southcote Junction.

The passenger services from Basingstoke routed into the low number platforms at Reading could also use this flyover and rejoin the existing route just south of Reading West. There would still be two potential flat conflicts - with the feeder lines to the diveunders near Oxford Road and at the throat of the Reading bay platforms - but one, at Southcote, would go. If there is space it might be possible to add a platform face on the west side of Reading West (platform 3?) with some S&C at Oxford Road to get a stopping train back to its original route. This might be possible if Reading West's Up platform was moved further south and would add some flexibility.

This scheme is certainly not all things to all men as some restrictions will still exist, for example on the occasions when these container freights would like to pass each other between Oxford Road and Southcote. In these circumstances I would suggest that the southbound train takes the same routing as now and one accepts any delay. Similarly a northbound passenger train from Basingstoke could take its existing route across Southcote Junction and not conflict with a southbound train off the proposed 'avoiding line'. Obviously there might still be issues with Reading - Newbury routed trains but the heavy container trains would be removed from the mix.

This might be a more 'buildable' and affordable alternative than Oxenhutch's comprehensive solution by concentrating on trying to remove one of the traffic flows from the existing tracks.

Right, where are the JCB's...?


Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: grahame on April 06, 2017, 06:14:52
Brief comment on "via Westbury" suggestions.  Route enhancements would be needed for any significant number of services.   Headways / sections south of Westbury are (I understand) long, you would need to do something about the 17 minute single line section (could be redoubled) and the flat junction at Royal Wootton Bassett and run into Swindon could become a bottleneck.  Some mechanism to hold / sidetrack trains that had left Westbury but not yet reached Swindon (and vice versa) would be needed too.   None of this is "mega" earthmoving stuff in comparison to threading another line through Reading West, I suspect, but the route isn't exactly slumbering through lazy summer days with just the occasional train disturbing the bees, butterflies, birds and bunnies at the moment.


Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: Noggin on April 06, 2017, 09:51:40
Another advantage of routing containers via Westbury is that it would enhance the business case for Southampton / Salisbury / Westbury / Bath / Chippenham electrification.

That would be a much more practical "electric spine" project, as it wouldn't require any intervention in existing 3rd rail areas, or the use of 3rd rail capable locos. Much of the services along the line could go over to EMU stock, and of course you'd greatly improve the business case for the extension of electrification of the B&H to Westbury, and the WEML to Salisbury (25kV from Basingstoke to Salisbury).

Also, you'd presumably free up paths between Didcot and Reading, which presumably would be useful if East/West railway services were to be routed into Reading.

The other question is of course whether Chippenham to Swindon could handle the volumes and whether it would be compatible with aspirations for new stations at Corsham and Wooton Bassett?


Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: CyclingSid on April 06, 2017, 10:13:23
The other "pinch point" on this route is where the line from Reading arrives at Basingstoke. There has been talk of grade separation but I haven't understood how they would fit it in.


Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: 4064ReadingAbbey on April 06, 2017, 11:12:19
The other "pinch point" on this route is where the line from Reading arrives at Basingstoke. There has been talk of grade separation but I haven't understood how they would fit it in.

See Figure 5.7 in NR's Wessex Route Study which can be found at <https://www.networkrail.co.uk/wp-content/uploads/2016/11/Wessex-Route-Study-Final-210815-1.pdf>


Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: stuving on April 06, 2017, 11:54:47
The other "pinch point" on this route is where the line from Reading arrives at Basingstoke. There has been talk of grade separation but I haven't understood how they would fit it in.

See Figure 5.7 in NR's Wessex Route Study which can be found at <https://www.networkrail.co.uk/wp-content/uploads/2016/11/Wessex-Route-Study-Final-210815-1.pdf>

Also, in Appendix B (p 151) they list several variations on that theme, including adding (or really reinstating - there were two more lines in 1937) another through platform line at the north of the station.

In terms of space, there is still quite a lot of old sidings land around the station, though it gets a bit tight as you go up the line towards Reading. Getting past the road overbridges is likely to be more of an issue. For that reason they might also look at a flyover to the west of the station, which together with that northern through line could do the same. It would not, however, provide the main enhancement they would like for passenger services - deconflicting a move from P1 on the south back towards London.


Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: stuving on April 06, 2017, 12:46:33
Having said that about the empty space around Basingstoke station, it occurred to me that I don't have (and can't find) any recent maps or images to check for encroachments. But I can think of two I've heard about - the ROC just to the north and Basingstoke Campus on the junction triangle. And guess what - both are Network Rail's!

I think the ROC is clear of the two through lines, as they are still there as the P5 line and siding next to it. But I suspect that the rail training centre was built with no passive provision for a flyover. And I'm not convinced that a flyover would work, anyway.

If you look at the land form, the station and the Reading Lines just past the A339 are both at 91 m elevation, while the main line you want to hop over (just to the east of the EMU sidings) is at 96 m. So that would provide almost all the grade separation needed for an underpass with hardly any gradient, or length. Going over the top, however, while staying goods-train-friendly, would need slopes so long you'd struggle to fit them in at all.

If the land was still empty, I'd say that building an underpass was not that difficult - you would build two temporary diversion lines and close two lines at a time to dig the holes. Lowering the cutting on the Reading Lines even a couple of metres would be much more disruptive, if that was essential. However, digging a cutting through the Campus might be a no-no. The play-tracks probably could be dug up for a while, but if there is no clear path avoiding new buildings ...


Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: stuving on April 06, 2017, 13:09:59
And another point arising from the Wessex Route Study, while I'm at it. It says there that the extra multi-modal path - the one that does the camel's-back thing to the junction - would have to be routed via Laverstoke and Andover anyway. There are capacity issues via Winchester, related to the length of twin-track that you'd be expecting trains of dissimilar speeds to share. So there is muttering (p 98) about extra loops, including a pair four miles long around Micheldever - but only to meet the 2043 requirement (i.e. CP10).

But if the Basingstoke grade separation - needed sooner - can't be done, or can't be approved due to its cost, wouldn't that change the arguments about where some of those container trains should be routed further north?


Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: Gordon the Blue Engine on April 06, 2017, 13:57:12
Grade separation is the ultimate “nice to have” solution to increase capacity and timetable robustness at flat junctions.  I’m not convinced that grade separation at Southcote J, which would be difficult and thus expensive, is necessary.  My modest idea to have reversible working on both lines between Reading Station and Southcote J, plus a new trailing crossover just west of Southcote J, would provide extra pathing opportunities at modest cost.   There must be many busier junction that work quite happily being flat – although long slow freights do complicate the comparison.

I think Basingstoke has a stronger case for grade separation.  My solution, not yet developed to Oxonhutch standards, is to double the flyover at Worting Junction, and then to add/ rearrange the tracks through Basingstoke so that southbound FL’s can stay north of the Southampton ML’s, go over the widened flyover, and then join the Southampton Down Line south of Worting Junction.

Worting J is in open country so land take would be easier.


Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: paul7575 on April 06, 2017, 14:14:47
Having said that about the empty space around Basingstoke station, it occurred to me that I don't have (and can't find) any recent maps or images to check for encroachments. But I can think of two I've heard about - the ROC just to the north and Basingstoke Campus on the junction triangle.

The relatively new signal building (known as Basingstoke New) alongside P5 (so immediately north of the station) is only temporary, it will all be moved into the ROC in due course.   The future ROC is the main function contained in the Basingstoke Campus, the training etc is the sideline.  The Campus is well away from any track.

But I think NR are trying to do far too much in the station area with the proposals in the Wessex route study.  I suggest they would be far better running the pair of Reading lines west of the station through two full length platforms, and sorting out the grade separation of the down line of that pair somewhere between Basingstoke and Working Jn. There's no real need for it to be at or near the existing flyover - doing it further east may allow it to descend between the two existing down lines which would possibly be more flexible.  The up line would just be a normal junction off the existing up slow.

If they still want a bay for Reading stoppers, then move it onto the other side of the existing platform.  Then the existing bay becomes P6, and a new up line towards Reading a P7.   Then leave the existing junction alone for reversionary routes during maintenance.

Paul


Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: Gordon the Blue Engine on April 06, 2017, 18:13:31
Yes, I think Paul 7755 and I have come up with the same key proposal, which is to run the Reading lines independently through Basingstoke station, and then to put in a grade separated junction to the west.  Whether you go for widening the flyover at Worting J or by some other grade separation between there and Basingstoke station is a detail which can follow later - exactly what you do would involve modelling of the options against the present and planned timetables.

(The layout north of East Croydon emerged from a project done by some management trainees in the 1970's, who came up with various ideas - there were quite a few - on grade separation and where various line went, and they modelled as above.)


Title: Re: Oxford Road and Southcote Junctions Grade Seperation
Post by: paul7575 on April 07, 2017, 10:57:47
[Re Basingstoke]

Another question is whether you have to remove every flat crossing move whatsoever.

If the up and down Reading lines ran through the station (what I suggested might be P6 and P7), would you really need an up direction passenger platform anyway?   Up direction XC services that currently pass through P4, (and are the majority of P4 services over the course of the day), could continue to do so using the existing route - they'd only have to be timed to cross with any down freights coming from Reading. 

Another suggestion to deal with the trains that terminate at Basingstoke, once down XC services are out of the picture over on a new through P6, then how about using P1 as the main through platform for down direction trains and putting the terminating trains in P2, from where they can return onto the up fast?

Paul




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