Network Rail's Western Route Study published for consultation - September 2015

[whole diary]

[paul7575]

Silly old me,  I took the trouble to search for the existing thread to provide the background...

Paul

[ChrisB]

Indeed, I thought I'd started one, but couldn't find it!

Maybe a Mod will combine into the future years board?

[Chris from Nailsea]

Maybe a Mod will combine into the future years board?

All done! 

[Adelante_CCT]

Had a good read through, especially the TV section, doesn't seem to be much different from the previous RUS^▸ (Route Utilisation Strategy). I did note however that they kept mentioning that the Marlow branch would be electrified, although I thought they recently ruled this out for practical reasons. There was also no mention of the potential extra crossover at Bourne End and that they would much rather have two shuttles (With Marlow pax always having to change at Bourne End if a 2tph all through the day was introduced) rather than any structural improvements.

[stuving]

It's interesting to look at some at least of the consultation submissions.

The ones in a folder called "Working Group and Board" (misleadingly below the link to the West of Exeter Route Resilience Study) are from other railway companies and organisations. None of these seems to acknowledge that they were involved in any way in the study. I know that previous submissions are often copied as public consultation comments just to get them on the record, but that's not how these ones read. See Chiltern's and Heathrow's in particular, which give a strong impression that they weren't asked at all.

In the LA submissions, Reading's is quite ... forceful. They are trying to make a case for retaining the semi-fasts (which are now listed as running on the reliefs, replacing the residual stopping trains, in the 2019 baseline). As part of this they label the paired mains and reliefs as outdated, and the 2-up 2-down pattern as modern. I don't think that's historically correct, and I suspect that by "modern" they may mean "continental", as that's where the examples would have to be.

I'd say that trying to run three services (long-distance, metro, and outer suburban/regional) that need three track pairs and doing that on two isn't ever going to work well. The suburban and metro could be linked on a 2-up 2-down basis, but with the long-distance separate. Perhaps it's not surprising that RBC^‡(resolve) give little weight to trains and passengers that go through Reading to somewhere else.

In response to HAL, the study does copy their list of adverse effects of "shunting" HEX onto reliefs, and also makes it clearer that's what they want post 2013. The baseline now includes the 4 tph on WRAtH^▸ (Western Rail Access to Heathrow), though they may be implemented post-2019, in addition to the 4 HEX and 4 Crossrail.

The topic of relief/main balance is even more important now, but not really analysed clearly. The option of running Crossrail trains on the mains is still included, though it conflicts with the need for more longer-distance paths. In considering the extra peak trains from Swindon, it says that pushing the main lines to 22 tph may not be feasible. Then option A13, grade separation at Ladbroke Grove, is now increased to very high value for money, citing these trains as an example of the benefits.

However, in option A17 (relief line enhancements, being two loops no longer identified as Langley-Hayes and Harlington) it says this to allow "semi-fasts" to at least overtake stoppers. It then says they would need to go down the tunnel, once the bulk of Crossrail trains to to Old Oak for HS2^▸ (The next High Speed line(s)). So now we have too many trains on both pairs of tracks. So ...

[didcotdean]

The FGW^▸ (First Great Western) response includes a suggestion to build platforms on the Didcot West curve (the RUS^▸ (Route Utilisation Strategy) already suggests building one on the East). These would be remote indeed from the main station, and would make any sense only if no other station was built between Didcot and Swindon.

[paul7575]

...As part of this they label the paired mains and reliefs as outdated, and the 2-up 2-down pattern as modern. I don't think that's historically correct, and I suspect that by "modern" they may mean "continental", as that's where the example would have to be.

There were logical reasons to retain the GW^▸ (Great Western) 'paired by use' layout with four tracking.  Most of the branches between London and Reading were on the north side of the line (except Windsor) and included through running services.  Any main terminal works better if services are grouped separately by type.   But now that new underpasses and flyovers have been built to suit paired by use operation at Acton Yard, Stockley and most of all at Reading, it is to all intents impossible to change to paired by direction now.

The WCML^▸ (West Coast Main Line) uses the same layout as GW from Euston as far as Rugby, then switches to paired by direction for the length of the Trent Valley.

The SWML^▸ (South Western Mail Line) uses paired by use at the terminal, then has a flyover between Earlsfield and Wimbledon and is paired by direction until Basingstoke (Worting Jn).   Paired by direction allows weaving from fast to slow and vice versa, but for a high frequency route with branches on both sides needs grade separation at most junctions.   Woking doesn't have grade separation and ends up as the limiting factor for service frequency on the whole mainline network.

Another problem with paired by use is that it is difficult to stop services at intermediate stations and turn back, unless you have a central siding, or yet more grade separation.

I don't think pairing by direction is exactly modern though, as implied by RBC^‡(resolve), the LSWR^▸ (London South Western Railway) converted their main route soon after four tracking out to New Malden (for Kingston), the original slow lines were on the down side all the way.

Paul

[stuving]

I don't think pairing by direction is exactly modern though, as implied by RBC^‡(resolve), the LSWR^▸ (London South Western Railway) converted their main route soon after four tracking out to New Malden (for Kingston), the original slow lines were on the down side all the way.

Paul

I'd see the LSWR main line as a case where it was built for long distance services, but grew more and more to be a suburban (inner and outer) railway. Hence its quadrupling and the adding of grade separation case by case was based on a suitable track layout. The Wimbledon Park flyover is visibly a lot newer than the grade separation structures, and was built (in 1936) to reinstate the separation by service at Waterloo after decades of 2-up 2-down operation. So its cost was evidently justified by the increase in terminal capacity that separation brings (currently P1-5 slow and P6-15 fast).

According to the Wessex Route Study (now also out in final form) this layout currently handles 24 tph peak, which might go up to 26 with a risk to reliability. After discussing various ways of squeezing a little more capacity out of the system, it suggests (p 85) that 5-tracking in to Clapham Junction, but no further, could allow 36 tph to run with only "additional switches and crossings in the Vauxhall area". Wow! I wish they'd tell the Western Route study team how they get that capacity out of two tracks to the throat and only flat junctions.

I say that because the Western Route Study says the main line capacity is limited to 24 tph by plaiting paths into and out of the platforms, though in 2019 it is only 16 tph due to constraints further out. And that is with spreading to four tracks well outside the throat, which I thought was important to realising even that capacity. Note that Waterloo has fewer platforms (ten) than Paddington will have post-Crossrail for main-line services, but then it has shorter dwell times too. In neither case is a shortage of platforms identified as a constraint.

To go even a little above that 24 tph limit, grade separation at Ladbroke Grove is advocated. I have not seen any description of what that might be - has anyone else? There is a sketch plan in Arup's latest Heathrow Hub submission which shows their interpretation - flying links from up (and down) main to relief, which makes no sense. I imagine it's more like a conflict-free way of splitting services into two groups with a pair of tracks each. But if that's needed for 26 tph, how on earth does Waterloo cope now, let alone with 36 tph?

I understand the Old Oak Common flyover is to be taken down, and its future use is certainly not mentioned. That is odd, in that there is an identified need (by 2019) to path trains off the relief Crossrail/lines and into Paddington platforms, and no capacity to do that after OOC^▸ (Old Oak Common (depot)) for HS2^▸ (The next High Speed line(s)) (or running on to the WCML^▸ (West Coast Main Line)) is in place. I reckon there is room to move a track from under that flyover to outside the ramps on each side of it, and so get at least a single track link to do just that. So, in the short term at least, that is a kind of grade separation at or near Ladbroke Grove.

[PhilWakely]

Moving further out from the Thames Valley, I note the following paragraph on page 10...

In the longer term, to accommodate the full 2043 ITSS, provision of four tracks between Exeter and Newton Abbot would be required. It would be difficult to achieve this alongside the existing coastal route, therefore one of the alternative route options developed as part of the West of Exeter Route Resilience Study may provide additional capacity and an alternative route that requires further consideration.

Call me cynical, but I can see this suggestion being very quickly and quietly dropped. I would willingly put a bet on the chances of me seeing my 100th birthday being greater than the likelihood of the above happening (if I make it to 2043, I will be 87 in that year!).