WCML Trent Valley upgrade

[Railperf]

While the North end of the Trent Valley stretch of WCML is 4 tracked and 100mph+ on both the fast and slow lines..the southern stretch is only 3 tracks with slow lines limited to 75mph. Is there any evidence to suggest this southern section is proving to be a performance / reliability liability. Should it have been upgraded to 4-tracks tbroughout?

 

[The Planner]

While the North end of the Trent Valley stretch of WCML is 4 tracked and 100mph+ on both the fast and slow lines..the southern stretch is only 3 tracks with slow lines limited to 75mph. Is there any evidence to suggest this southern section is proving to be a performance / reliability liability. Should it have been upgraded to 4-tracks tbroughout?

4 would be useful, but considering you still end up regulating at Rugby on the up anyway Im not sure what it would unlock.

 

[jfollows]

It's fortunate that the single track in normal operation is the down line because down trains are probably more reliably on time than up trains. I have noted a number of freight trains waiting on the down slow north of Rugby for the passing of the xx.40 service to Manchester via Crewe; after this service there's a gap of 17 minutes until the xx.46 110mph Euston-Crewe service, so the freight trains get funnelled through this gap. It's only a bit more than 7 miles in length also, so I don't see that it has to be a major performance or reliability problem, of course it would be better if it were four tracks throughout but I suspect the price:benefit calculation would result in the money being better spent elsewhere.

 

[LNW-GW Joint]

While the North end of the Trent Valley stretch of WCML is 4 tracked and 100mph+ on both the fast and slow lines..the southern stretch is only 3 tracks with slow lines limited to 75mph. Is there any evidence to suggest this southern section is proving to be a performance / reliability liability. Should it have been upgraded to 4-tracks tbroughout?

The LNR Euston-Crewe service via the TV route could be even faster without the 75mph trundle southbound between Tamworth and Rugby on the Slow (from Attleborough northbound).
I don't think the 75mph sections were touched during WCRM (except for resignalling) so you might expect issues with the ageing OHLE and other old bits.
With HS2 coming, there won't be much incentive to spend money on it.
Adding a Down Slow on the 7 miles between Brinklow and Attleborough would be expensive too, with the Oxford Canal just over the fence.
The 2-track section through Shugborough tunnel would also still be an issue for main line traffic.

Stafford-Crewe was eventually upgraded from 75 to 90mph, along with the Norton Bridge work.
North of Crewe, the Slow lines, where they exist, are all 75mph.
I dimly remember SRA aspirations for WCRM to upgrade the Northampton Loop and fit tilt, which didn't happen either.

 

[30907]

4 would be useful, but considering you still end up regulating at Rugby on the up anyway Im not sure what it would unlock.

It's the Down that is "single" and you would still have the problem that the Dn Slow is the middle of the 3 to Brinklow but on the outside (conventionally) from Attleborough - a thorough solution would involve an expensive flyover!

 

[The Planner]

It's the Down that is "single" and you would still have the problem that the Dn Slow is the middle of the 3 to Brinklow but on the outside (conventionally) from Attleborough - a thorough solution would involve an expensive flyover!

I know, but you will still normally have a freight outside the ROC on the up. You only kick the problem down the road to Colwich even if it was 4 tracks.

 

[jyte]

After TV four tracking, the location of the down fast line switched from being the outer paired by direction line to inner paired by direction line. The logic of this is debatable (as it forces trains further north to slow to 60mph to cross back onto the slow lines to go via Stafford) but at Rugby the fast line is outer, so you'd need an X crossover anyway to swap fast trains anyway.

Also, I remember reading somewhere (but now can't find where) that the M6 overbridge over the WCML was built with supports that are not wide enough to permit running four lines through there.

Providing four tracks as far as Colwich (including the Northampton loop) would be lovely, but doing it properly would likely involve a new flying junction somehwere between Rugby and Nuneaton to swap the down fast and slow lines, rebuilding a motorway bridge, and would just move the problem further north to Colwich, which everyone seems to regard as a rather unsolvable (as in, not worth it) problem which has largely been resolved by Norton Bridge.

Edit: re my claim regarding the M6 motorway overbridge, I've gone and watched a cab ride down the trent valley and I'm pretty sure there would be room for a 4th track thete if needed - see screenshot.

 

[zwk500]

It's the Down that is "single" and you would still have the problem that the Dn Slow is the middle of the 3 to Brinklow but on the outside (conventionally) from Attleborough - a thorough solution would involve an expensive flyover!

But given how often anything gets held at Brinklow, there's not really a significant capacity constraint. It would be nice to have the 4 tracks, but it's a lot of money for a slightly more convenient option.

After TV four tracking, the location of the down fast line switched from being the outer paired by direction line to inner paired by direction line. The logic of this is debatable (as it forces trains further north to slow to 60mph to cross back onto the slow lines to go via Stafford) but at Rugby the fast line is outer, so you'd need an X crossover anyway to swap fast trains anyway.

The logic is fine for the 3-track plan, as all trains are going to filter onto the same track anyway.

Also, I remember reading somewhere (but now can't find where) that the M6 overbridge over the WCML was built with supports that are not wide enough to permit running four lines through there.
Edit: re my claim regarding the M6 motorway overbridge, I've gone and watched a cab ride down the trent valley and I'm pretty sure there would be room for a 4th track thete if needed - see screenshot.

That looks very tight for 4-tracks to me, especially for 110/125 dynamic profiles. however you may be able to put one of the outer tracks through a different span (possibly with a PSR).

Providing four tracks as far as Colwich (including the Northampton loop) would be lovely, but doing it properly would likely involve a new flying junction somehwere between Rugby and Nuneaton to swap the down fast and slow lines, rebuilding a motorway bridge, and would just move the problem further north to Colwich, which everyone seems to regard as a rather unsolvable (as in, not worth it) problem which has largely been resolved by Norton Bridge.

You could also resolve the alignment problems by rebuilding the Southern end of Rugby, if avoiding a simple switchover was that big of a deal. Colwich is going to be largely resolved by one of the HS2 phases, isn't it?

 

[The Planner]

You wouldn't have the room for a fast switch at the south end, and it just adds more operational constraints, but you would make P2 at Rugby the Down Fast. Any new fourth track north of Brinklow is the Down Slow.

 

[Bald Rick]

It's fortunate that the single track in normal operation is the down line because down trains are probably more reliably on time than up trains.

Anyone would think that it was planned that way

 

[Nottingham59]

however you may be able to put one of the outer tracks through a different span (possibly with a PSR).

Plenty of space between the canal and the railway.

 

[The Planner]

Plenty of space between the canal and the railway.
View attachment 121280

Have a look a bit further south to see the other issue with the canal.

 

[The Chimaera]

Edit: re my claim regarding the M6 motorway overbridge, I've gone and watched a cab ride down the trent valley and I'm pretty sure there would be room for a 4th track thete if needed - see screenshot.

That motorway bridge would have room for another track but the (M42?) Motorway bridge just north of Shilton would not unfortunately. HS2 will relieve the pressure on this section of the wcml anyway so I can’t see a need in the foreseeable future.