Lines which could do with improved signalling headways/more aspects

[Bald Rick]

Only if it’s still lights-on-sticks.

Yes that’s true.

 

[Kite159]

St Denys to Fareham via Netley.

 

[The Planner]

Perhaps something to be considered as part of a wider WCML upgrade post HS2

West Coast North Modernisation has ETCS in its scope, but its at least a decade or more away.

Only if it’s still lights-on-sticks.

Will be lights on sticks on that bit for at least another 20 years Id bet.

 

[Harpo]

Will be lights on sticks on that bit for at least another 20 years Id bet.

And I’d not bet against that. Unless of course folks on this thread have found the crayon-melting levels of enhancement funding needed for even one of these ventures.

 

[Bill57p9]

Maybe stretching this one a bit, however resilience on the West Highland Line would benefit from one or two additional passing loops: there are some very long sections including a couple of passing loops (Corrour and Gorton) that are RETB block posts although without the usual other infrastructure (hydraulic points, TPWS, etc.) to allow them to be useful loops.

 

[brad465]

Is the Midcalder line between Carstairs and Kirknewton still mostly 2-aspect? This feels like somewhere that should be at least 3-aspect, then 4-aspect from Kirknewton to Haymarket (only the last bit into Haymarket is 4-aspect IIRC).

 

[AlastairFraser]

West Coast North Modernisation has ETCS in its scope, but its at least a decade or more away.

So 2035 at the earliest? Perhaps some trackwork could be done before them.

 

[The Planner]

So 2035 at the earliest? Perhaps some trackwork could be done before them.

You won't get any four tracking in this scheme.

 

[class 9]

The Wharfedale line between Guiseley and Burley.

 

[Helvellyn]

Midland Mainline between Sharnbrook and Leicester, which was resignalled with three aspect signalling by BR in the 1980s to replace semaphores. It was generally two HSTs an hour, with some peak additional. Now six trains an hour as far as Kettering. When this comes up for renewal moving to four aspect signalling with shorter sections would improve resilience. With the steady growth provided by the EMR Connect service it also gives potential to add stops on the Sheffields at Kettering, or (subject to rolling stock) extend say Thameslink's Fast Brighton services to Kettering, making Kettering a good interchange hub.

 

[Trainman40083]

Midland Mainline between Sharnbrook and Leicester, which was resignalled with three aspect signalling by BR in the 1980s to replace semaphores. It was generally two HSTs an hour, with some peak additional. Now six trains an hour as far as Kettering. When this comes up for renewal moving to four aspect signalling with shorter sections would improve resilience. With the steady growth provided by the EMR Connect service it also gives potential to add stops on the Sheffields at Kettering, or (subject to rolling stock) extend say Thameslink's Fast Brighton services to Kettering, making Kettering a good interchange hub.

If I remember correctly. Midland Mainline should follow the East Coast Mainline with digital signalling. So it won't need lineside signalling at all....Can't recall how far up the plan was. I'd have thought Leicester at least.

 

[bramling]

What lines have the strongest case for increasing the number of signals along it, without necessarily having any other changes to the infrastructure?

Two I can think of are:

- Castle Cary-Cogload Jct: currently 2-aspect and has a very long block between just west of Castle Cary and Somerton. It's not uncommon in the down direction for a fast train to catchup to a semi-fast ahead of it, even if they are still technically 7-8 minutes ahead. Making this 3-aspect, or at the very least adding another one or two blocks, would increase capacity and improve resilience.

- Maidstone East line: currently 3-aspect, but the blocks are notably long, possibly because it's a core freight route with no freight speed differentials. This is a particular problem in the peaks (where 4tph run at uneven intervals) and/or when a freight train traverses at certain times. I think this could do with some 4-aspect sections, especially around Otford and Maidstone East, and/or shrinking the signal blocks and having something like a 50-55mph freight limit (they hardly reach the 70-80mph limit anyway), similar to Swanley-Otford.

Not sure about strongest case, however Queen’s Park to Harrow & Wealdstone, and especially north of Stonebridge Park, has sections which are somewhat long for the frequency of trains which go up there. On paper it’s fine for 8tph which is the current service, but in practice trains tend to run off schedule due to the way the Bakerloo Line works, which the signalling then struggles to accommodate - it’s said on LU that trains leave Queen’s Park going north and it’s almost pot luck what time they arrive back on the southbound.

 

[AlastairFraser]

You won't get any four tracking in this scheme.

Which would reduce the BCR, no?

 

[The Planner]

Which would reduce the BCR, no?

No, as its not technically an enhancement project.

 

[cle]

Not sure about strongest case, however Queen’s Park to Harrow & Wealdstone, and especially north of Stonebridge Park, has sections which are somewhat long for the frequency of trains which go up there. On paper it’s fine for 8tph which is the current service, but in practice trains tend to run off schedule due to the way the Bakerloo Line works, which the signalling then struggles to accommodate - it’s said on LU that trains leave Queen’s Park going north and it’s almost pot luck what time they arrive back on the southbound.

Is has previous run 6tph Stonebridge and 6tph Harrow (plus 3tph Watford DC) - which is 15 north of QP. The Watford is now 4tph and the Bakerloo has diminished, but I think it would be able to handle anything demanded right now.

If the Bakerloo extension was ever done, they'd need to think about what to do with a reinstatement or even increase in service, as the southern end would surely gobble up more than 24tph.

 

[The Planner]

Is has previous run 6tph Stonebridge and 6tph Harrow (plus 3tph Watford DC) - which is 15 north of QP. The Watford is now 4tph and the Bakerloo has diminished, but I think it would be able to handle anything demanded right now.

If the Bakerloo extension was ever done, they'd need to think about what to do with a reinstatement or even increase in service, as the southern end would surely gobble up more than 24tph.

Signalling headway is higher north of Harrow.

 

[danielnez1]

The double block signalling on the Pelaw - Sunderland section of the Durham Coast line could be removed with the old Metrocar fleet is fully withdrawn (double block signalling was introduced to reduce the likelihood of head on collisions between mainline trains and the very lightweight Metrocars). Reopening the closed platforms at Sunderland exclusively for Metro use would probably further help with line capacity too.

 

[AlastairFraser]

No, as its not technically an enhancement project.

Fair enough, it's a shame that it can't be bundled into the renewal project.

 

[brad465]

Apart from on the Trans-Pennine Route, are there any schemes in the pipeline actually confirmed for improving headways?

 

[zwk500]

One improvement I'd look at is at least 1 additional block between Crewe and Beeston. Ideally resignal the whole length to abolish Crewe Steel Works and Beeston Castle boxes for a straight 4 minute headway, but the service would probably cope with 1 IB section between the two AB areas.

Brighton-Lewes could also do with the stopping headway being reduced a bit. Especially with the football specials.

Apart from on the Trans-Pennine Route, are there any schemes in the pipeline actually confirmed for improving headways?

You can get a good idea from looking at the change notes at the front of the TPRs published on NR's website, although this will only cover the next 2 years or so at most, so only schemes definitely being delivered. https://www.networkrail.co.uk/industry-and-commercial/information-for-operators/operational-rules/

 

[The Planner]

One improvement I'd look at is at least 1 additional block between Crewe and Beeston. Ideally resignal the whole length to abolish Crewe Steel Works and Beeston Castle boxes for a straight 4 minute headway, but the service would probably cope with 1 IB section between the two AB

Already planned to be done.

 

[zwk500]

Already planned to be done.

The IB or the full 4-minute headway? And for when...

 

[The Planner]

The IB or the full 4-minute headway? And for when...

Getting rid of the boxes. Might not be a 4 minute headway, but its due before the end of the control period.

 

[zwk500]

Getting rid of the boxes. Might not be a 4 minute headway, but its due before the end of the control period.

Interesting, thought that would have to wait for Signals-Away ETCS.

 

[MarkyT]

The double block signalling on the Pelaw - Sunderland section of the Durham Coast line could be removed with the old Metrocar fleet is fully withdrawn (double block signalling was introduced to reduce the likelihood of head on collisions between mainline trains and the very lightweight Metrocars). Reopening the closed platforms at Sunderland exclusively for Metro use would probably further help with line capacity too.

If I recall correctly, the closely spaced 4 aspect signals have their overlaps extended to the next signal rather than a nominal point ~200yds ahead of the signal, so the clear headway distance separation is typically 1.5D+S+L rather than 1.5D+S+O+L (where D(4-asp) is signal spacing @~Braking Distance/2, S is sighting distance (nominally say 500m on such a slow line), O is overlap (typically 183m though can be shorter in low speed areas), L is train length (nominally 100m for most passenger trains on this line)). The new metro vehicles, while no doubt stronger than the old ones, are still largely based on light metro practice and have the same train protection system onboard. I can't see any benefit in or likelihood of reducing the protection provided to these trains by the infrastructure, and, because the signal spacing is so short, there wouldn't be very much capacity improvement in doing so anyway. The shared track is dual-equipped with Metro's Indusi-based train-stop system and National Rail TPWS/AWS. Both sets of track transponders are provided at each main signal.

 

[Magdalia]

Apart from on the Trans-Pennine Route, are there any schemes in the pipeline actually confirmed for improving headways?

From next Monday Shelford-Cambridge will have 7 signal berths instead of 5.

 

[The Planner]

Interesting, thought that would have to wait for Signals-Away ETCS.

Was meant to happen about 10 years ago.