Welwyn Viaduct Bottleneck

[tbtc]

It's been considered many times before, and it is difficult to make the case. Yes it releases capacity at this location, but there isn't the space elsewhere on the route (not least KGX) to make use of it

This is the problem with the upgrades suggested as an alternative to HS2 - doubling capacity at one bottleneck (like Welwyn) just creates a pinch point further up (or down!) the line.

There will be more capacity at KX when some of the FCC servics move to the Thameslink core, but the ECML isn't four track all the way to Doncaster, so its not like a bigger viaduct (or whatever) at Welwyn would suddenly mean there was room for loads of extra services.

 

[cle]

That would seem rather odd, if not stupid. Who would want to be on an all-station stopper that goes through the core? It would take ages!

There are of course semi-fast trains that terminate at WGC in the peaks (to reserve paths over the viaduct) and I could see that these might go through. The only reason they currently have a few stops along the way is to stop them catching up with the slows from Moorgate, which they usually do by Potters Bar - and then crawl behind to allow the slow to stop at Brookmans Park and Welham Green.

If London Overground does happen, I am sure there will be trains to Moorgate AND trains to King's Cross (or beyond) which will fill out the slows quite considerably!

Edit: BTW, they may be planning to cope with 24tph but surely only in the peaks, so perhaps they won't be running that many slow trains throughout the day and into the night?

I am sure the plans will change anyway, as there have been discussions and quite often we get 'the current thinking...' posts which suggests nothing is fully decided. My comment about not bothering with the link was only opinion, not a serious suggestion that they don't do it!!

People do live at the slow stations too! And Thameslink should be for Londoners as much as Home Counties people as long as it's relieving London termini.

I could see:

All trains from Moorgate running (on LOROL) via Hertford loop - none stopping at Harringay and Hornsey, and using the new lines they are modernising (which don't have platforms at the two Hs)

Slow Welwyns being split between Thameslink and Kings X terminating. Or being re-cast with the Cambridge/Peterborough slows to address the stopping patterns.

Therefore Moorgate could be run high frequency by a completely different TOC - meeting only at Finsbury Park (own platforms) and Stevenage, Hitchin and Letchworth.

 

[HSTEd]

This is the problem with the upgrades suggested as an alternative to HS2 - doubling capacity at one bottleneck (like Welwyn) just creates a pinch point further up (or down!) the line.

There will be more capacity at KX when some of the FCC servics move to the Thameslink core, but the ECML isn't four track all the way to Doncaster, so its not like a bigger viaduct (or whatever) at Welwyn would suddenly mean there was room for loads of extra services.

Then we go to the next bottleneck, and the next and the next till we reach Doncaster :P

EDIT:
1. Duplicate the Welwyn Viaduct/Tunnels
2. Installation of a proper flyover at Hitchin
3. Installation of two new Platforms at Letchworth GC to support a high intensity LOROL service via Hertford Loop from Moorgate
4. Increase from a combination of two and three tracks to four between Huntingdon and Peterborough
5. Atleast one additional platform at Peterborough
6. Flyover north of Peterborough that carries the Down line of the Peterborough-Lincoln line over the fasts and Up Slow.
7. Integration of the two tracks of the Birmingham-to-Peterborough line with the ECML as far as Helpston with electrification and a flyover to carry the Up line of the former over the ECML at that location.
8. Duplication of Stoke Tunnel to carry four tracks
9. Extension of four track line to Grantham station, with a flyover south of the station to carry the Up Slow over the Fasts.
10. Remodelling of Grantham station with four full length platforms.
11. Addition of a fourth running line between Grantham station and the Nottingham branch junction, replacement of the single lead with a simple divergence.
12. Electrification of the Grantham-to-Nottingham line as far as Allington Junction.
13. Electrification of Allington Chord and the Grantham Avoiding line as far as the ECML flyover.
14. Addition of two new single track cords to permit trains to join the ECML northbound
15. Addition of two new slow lines between this junction and Newark
16. Remodelling of Newark Northgate with four full length platforms.
17. New bridge to carry the Newark Castle lines over the ECML, eliminating the flat crossing.
18. Addition (if possible) of a flyover to carry a second line for the ECML-Castle line chord over the fasts to enable more regular trains to Lincoln from London
19. Broadening of the route between Newark and Doncaster with any neccesary modifications to Retford (dont know enough about that station to be any more specific)
20. Replacement of the divergence between the Wakefield Line and Doncaster with a proper junction complete with a flyover to carry the Up line from Leeds over the ECML lines.
21. Two new running lines between Doncaster and Shaftholme Junction
22. New flyover at Shaftholme Junction to carry the Up slow over the Fast lines to join the Down Slow which will become the Askern Up and Down.
23. Addition of a new diveunder to allow trains from Thorne to reach the Askern Line.
24. Electrification of the Askern line to Knottingley
25. Electrification of line between Knottingley and Colton Junction via Sherburn-in-Elmet
26. Installation of a flyover at Colton Junction allow trains to reach the Leeds-to-York line from the Up Slow without obstructing the Fast lines.
27. Installation of ETCS Level 2 throughout
28. New Class 378s for the Moorgate-Letchworth Garden City services and faster accelerating, possibly tilting trains for ECML services (including the "Cambridge Cruiser")

That enough to be getting on with? It gives increased capacity south of Doncaster/York and doesnt destroy the Intercity service on the southern ECML in favour of nonexistant local services to do it.

EDIT #2.
It occurs to me that it might be a good idea to have six tracks between the Hertford Loop junction and the Hitchin flyover if this can be achieved without too much trouble as it would enable my proposed LOROL service to stay completely out of the way of the other services on the slows at that point.

Also I am not against High Speed 2 or anything, I just dont like that the Leeds branch will probably be used as an excuse to degrade the existing service patterns.

 

[tbtc]

Then we go to the next bottleneck, and the next and the next till we reach Doncaster :P

Thats it.

Four track over Welwyn and then you have to deal with the two two-tracked tunnels south of Knebworth.

Solve that problem and then there's the lack of four track north of Huntingdon.

And the flat crossings at Peterborough (e..g. the Liverpool - Norwich has to cross the fast northbound track on the level).

Then there's Stoke tunnel around Grantham, and then generally two track north of Grantham.

Plus the flat crossing at Newark (on the Lincoln - Nottingham line)...

And as for Doncaster itself (with at least six movements an hour on the flat junctions between the Sheffield line and the Thorne lines)...

Much easier to just build a separate line (whether its HS2 or the Virgin plan for a parallel ECML).

Really, the Welwyn Viaduct is only one of the problems, and to spend tens of millions "solving" it would just make other places the "weakest link" on the ECML

 

[HSTEd]

Thats it.

Four track over Welwyn and then you have to deal with the two two-tracked tunnels south of Knebworth.

Solve that problem and then there's the lack of four track north of Huntingdon.

And the flat crossings at Peterborough (e..g. the Liverpool - Norwich has to cross the fast northbound track on the level).

Then there's Stoke tunnel around Grantham, and then generally two track north of Grantham.

Plus the flat crossing at Newark (on the Lincoln - Nottingham line)...

And as for Doncaster itself (with at least six movements an hour on the flat junctions between the Sheffield line and the Thorne lines)...

Much easier to just build a separate line (whether its HS2 or the Virgin plan for a parallel ECML).

Really, the Welwyn Viaduct is only one of the problems, and to spend tens of millions "solving" it would just make other places the "weakest link" on the ECML

See above, it tends to be that everyone on this "High Speed" or "Duplicate Line" sees major improvements in services and everyone else looses out, the WCML debacle seems to have forever poisoned the reputation of "upgrades" in this country and now we must embrace the brand new line construction model.

EDIT: On further thought I'm all for having HS2 extend to Leeds, so long as a major ECML upgrade happens so taht it remains the default route for Intercity trains from the North East, no sense overloading Euston and wasting all the capacity at KGX, not to mention obliterating the service to places on the Southern ECML.

 

[Bald Rick]

Then we go to the next bottleneck, and the next and the next till we reach Doncaster :P

EDIT:
1. Duplicate the Welwyn Viaduct/Tunnels
2. Installation of a proper flyover at Hitchin
3. Installation of two new Platforms at Letchworth GC to support a high intensity LOROL service via Hertford Loop from Moorgate
4. Increase from a combination of two and three tracks to four between Huntingdon and Peterborough
5. Atleast one additional platform at Peterborough
6. Flyover north of Peterborough that carries the Down line of the Peterborough-Lincoln line over the fasts and Up Slow.
7. Integration of the two tracks of the Birmingham-to-Peterborough line with the ECML as far as Helpston with electrification and a flyover to carry the Up line of the former over the ECML at that location.
8. Duplication of Stoke Tunnel to carry four tracks
9. Extension of four track line to Grantham station, with a flyover south of the station to carry the Up Slow over the Fasts.
10. Remodelling of Grantham station with four full length platforms.
11. Addition of a fourth running line between Grantham station and the Nottingham branch junction, replacement of the single lead with a simple divergence.
12. Electrification of the Grantham-to-Nottingham line as far as Allington Junction.
13. Electrification of Allington Chord and the Grantham Avoiding line as far as the ECML flyover.
14. Addition of two new single track cords to permit trains to join the ECML northbound
15. Addition of two new slow lines between this junction and Newark
16. Remodelling of Newark Northgate with four full length platforms.
17. New bridge to carry the Newark Castle lines over the ECML, eliminating the flat crossing.
18. Addition (if possible) of a flyover to carry a second line for the ECML-Castle line chord over the fasts to enable more regular trains to Lincoln from London
19. Broadening of the route between Newark and Doncaster with any neccesary modifications to Retford (dont know enough about that station to be any more specific)
20. Replacement of the divergence between the Wakefield Line and Doncaster with a proper junction complete with a flyover to carry the Up line from Leeds over the ECML lines.
21. Two new running lines between Doncaster and Shaftholme Junction
22. New flyover at Shaftholme Junction to carry the Up slow over the Fast lines to join the Down Slow which will become the Askern Up and Down.
23. Addition of a new diveunder to allow trains from Thorne to reach the Askern Line.
24. Electrification of the Askern line to Knottingley
25. Electrification of line between Knottingley and Colton Junction via Sherburn-in-Elmet
26. Installation of a flyover at Colton Junction allow trains to reach the Leeds-to-York line from the Up Slow without obstructing the Fast lines.
27. Installation of ETCS Level 2 throughout
28. New Class 378s for the Moorgate-Letchworth Garden City services and faster accelerating, possibly tilting trains for ECML services (including the "Cambridge Cruiser")

That enough to be getting on with? It gives increased capacity south of Doncaster/York and doesnt destroy the Intercity service on the southern ECML in favour of nonexistant local services to do it.

EDIT #2.
It occurs to me that it might be a good idea to have six tracks between the Hertford Loop junction and the Hitchin flyover if this can be achieved without too much trouble as it would enable my proposed LOROL service to stay completely out of the way of the other services on the slows at that point.

Also I am not against High Speed 2 or anything, I just dont like that the Leeds branch will probably be used as an excuse to degrade the existing service patterns.

Wow. That's about £10bn of work for essentially more trains (with nowhere to terminate in London) at the same speed. Also no weekend service for at least 5 years while it was built. Alternatively we could spend rather less of our money on the Leeds branch of HS2 for more trains which go faster.

Ref another post, I don't think Thameslink releases capacity at KX as the suburban platforms are not much use for 12 car trains and get removed following commencement of the through service. That was certainly the plan but it may have changed.

 

[HSTEd]

Wow. That's about £10bn of work for essentially more trains (with nowhere to terminate in London) at the same speed. Also no weekend service for at least 5 years while it was built. Alternatively we could spend rather less of our money on the Leeds branch of HS2 for more trains which go faster.

Ref another post, I don't think Thameslink releases capacity at KX as the suburban platforms are not much use for 12 car trains and get removed following commencement of the through service. That was certainly the plan but it may have changed.

Actually that can get you 170mph running on the fasts in the vicinity of Huntingdon-Peterborough-Grantham-Newark-Doncaster-York and greater average speeds further south since you can cross the Welwyn Viaduct at full speed. It also doesnt result in the massive degradation of service to everyone between Doncaster and Stevenage.
Also I think £10bn is rather an overestimate, since that would make it more expensive than the entire WCML debacle.

Anyway, why would they remove the platforms, surely they can find some use for them or do they want to sell the land off?
We could always you know... run 8 carriage trains into the old Suburban platforms.

And where will the HS2 trains be terminating?
The magical TARDIS like Euston station?

 

[jopsuk]

If you deal with the Welwym viaduct and the tunnels through to Knebworth plus the Hitchin flyover, the remaining "bottlenecks" don't deal with anywhere near as much traffic- remember, off peak there are four trains to Cambridge plus the Letchworth terminators. Four track all the way to Peterborough and the traffic drops drastically again- no part of the ECML has such an intensive "local" service as the FCC area.

 

[cle]

Once leaving Huntingdon (northbound) - won't future units be able to do at least 110 (I would hope for units like 395s doing 125!) and keep up with EC slots? There are no other stations and it's a clear route - assuming platform space at Peterborough.

 

[swt_passenger]

Wow. That's about £10bn of work for essentially more trains (with nowhere to terminate in London) at the same speed. Also no weekend service for at least 5 years while it was built. Alternatively we could spend rather less of our money on the Leeds branch of HS2 for more trains which go faster.

Ref another post, I don't think Thameslink releases capacity at KX as the suburban platforms are not much use for 12 car trains and get removed following commencement of the through service. That was certainly the plan but it may have changed.

The platforms aren't closing AFAICS, it hasn't ever been mentioned in anything I've read - have you thought that they aren't needed if ALL services into Kings Cross became 12 car EMU or LHCS?.

The London and SE RUS still shows a peak 2 tph 8 car stopping service into Kings Cross from Cambridge, and of course the suburban platforms can always accept the GC and HT services in the offpeak period.

 

[shinkansen1966]

How about re-positioning Welywn North station on the south side of Digswell viaduct just prior to the point where four tracks become two ?

 

[ainsworth74]

Also I think £10bn is rather an overestimate, since that would make it more expensive than the entire WCML debacle.

But your plan is rather more complex than what the WCML modernisation became. You want to build new tunnels, bridges, fly overs, platforms, increase the number of tracks through some sections and provide for tilting trains which, granted, the WCML programmed delivered for less than £10bn. But then you also want to resignal the route to ETCS2 (which means a lot of existing cabs need refitting for ETCS2) as well as raise line speeds to 170mph . The WCML was going for moving block signalling (which is somewhat comparable to ETCS2) and 140mph at a projected cost of £13bn (and that's in 2001 £££s) I think it's perfectly reasonable to assume that £10bn might in fact be an underestimate rather than an overestimate!

 

[tbtc]

Once leaving Huntingdon (northbound) - won't future units be able to do at least 110 (I would hope for units like 395s doing 125!) and keep up with EC slots? There are no other stations and it's a clear route - assuming platform space at Peterborough.

And no freight?
--- old post above --- --- new post below ---

See above, it tends to be that everyone on this "High Speed" or "Duplicate Line" sees major improvements in services and everyone else looses out, the WCML debacle seems to have forever poisoned the reputation of "upgrades" in this country and now we must embrace the brand new line construction model.

EDIT: On further thought I'm all for having HS2 extend to Leeds, so long as a major ECML upgrade happens so taht it remains the default route for Intercity trains from the North East, no sense overloading Euston and wasting all the capacity at KGX, not to mention obliterating the service to places on the Southern ECML.

Thats an interesting list (which I hadn't seen when making my previous comment last night).

But that's tens of millions of pounds just to upgrade one route. One of the frequent complaints about HS2 is that "it does nothing for (insert name of town not directly on route)". I can't see all those improvements to the ECML being allowed without politically balanced spending elsewhere too.

 

[HSTEd]

But your plan is rather more complex than what the WCML modernisation became. You want to build new tunnels, bridges, fly overs, platforms, increase the number of tracks through some sections and provide for tilting trains which, granted, the WCML programmed delivered for less than £10bn. But then you also want to resignal the route to ETCS2 (which means a lot of existing cabs need refitting for ETCS2) as well as raise line speeds to 170mph . The WCML was going for moving block signalling (which is somewhat comparable to ETCS2) and 140mph at a projected cost of £13bn (and that's in 2001 £££s) I think it's perfectly reasonable to assume that £10bn might in fact be an underestimate rather than an overestimate!

No... Moving Block Signalling is ETCS3-equivalent.
ETCS2 utilises the existing interlocking equipment where possible whereas ETCS3 requires software based equipment dissimilar to all widespread (in the UK atleast) designs (you cant use SSI or anything derived from it).

ETCS2 does have the benefits associated with reduced trackside equipment (reducing the amount that can go wrong or grow legs and walk off) and there will be a significant base for ETCS2 fitment soon with the GWML apparently acquiring it during its upgrade programme.

Anyway I must admit that £10bn could be an underestimate even though the distances involved are much smaller, Il work out a detailed proposal based on mileage of new track and wiring and then look at similar recent projects to get a better idea.


As for the suburban platforms, as I understand it that will free anywhere between 4 and 7 (Im not sure if it is currently 4tph to Cambridge (excluding non stop)/WGC all the time or just at peak times when Moorgate trains run in there too) from theThameslink Programme and my proposal for LOROL trains out of Moorgate all day and at weekends.
If we assume 4tph freed, that would allow clockface hourly services to Lincoln, Hull, Middlesborough and Sunderland, none of which are likely to need trains longer than 160m at such high frequency (indeed only two of those places get trains longer than 160m anyway, and both are 1tpd, the Lincoln train and the Hull Executive). These trains would alleviate demand no the southern ECML even if they dont go to the conventional destinations.

EDIT:
As to the Political requirement for balancing spending: the West Country/South Wales gets the GWML rebuild, the North West gets HS2 and the South has lots of everything.

 

[jopsuk]

Peterborough is an interesting one. How would you lay it out, if you had a fantasy budget and weren't too concerned about the restriction imposed by the bridges over the Nene? Given the following need to be accommodated:
Fast trains not stopping
ECML through trains
Through trains from/to Stamford and beyond to/from March and beyond
Through trains from/to Grantham and beyond to/from March and beyond
Terminating trains from the March line
Terminating trains from the Lincoln line
Terminating GN trains- which need also to be able to access carriage sidings, be they to the north or south in your fantasy layout.

 

[MidnightFlyer]

I'd just plump for a very complex series of crossovers and flyovers north of the station and a couple of south-facing bays. Peterborough has to have one of the most complex layouts for a through station in the country, surely?

 

[HSTEd]

Well, given unlimited funding I would propose the following:

1. Close and relocate the Nene Carriage sidings to open fields roughly half way between Whittlesea and Peterborough, extending electrification to allow this to happen.

2. Increase the tracks across the current Nene Bridges to six (add a third bridge to the western side of the current two) and have the fast lines cross the middle bridge. (Have trains come off the fast lines if they wish to stop).

3. Add a new bridge over the nene to the east of the current ones to carry a single track chord between the current ECML Up Slow and the line to March.

4. Bury the Fast lines in a cut and cover tunnel under the current central avoider lines, starting somewhere in the vicinity of the former carriage sidings and ending somewhere north of the station where room to fit in the portal can be found.

5. Close the south facing bay to the East of station as it would be impossible to access without going down on the up "side" of the station.
6.

Completely rebuild the current two islands and one side platform as one side platform and three islands in a similar space, thanks to the removal of the avoiding lines and the wasted space surrounding them.

Platform 1 would be for Norwich trains and would also act as a Freight through line
Platform 2 would be Up EC trains
Platform 3 would be Up EC trains and terminating GN trains
Platform 4 would be Down EC trains and terminating GN trains
Platform 5 would be Down EC trains
Platform 6&7 would be local trains terminating in Peterborough
Freight avoiders would be posistioned west of the current station.

There would be a single track flyover north of the station to permit trains from Stamford to reach 6&7 without blocking up the throat of the station crossing over the other lines (thanks to my integration fo the line to Stamford with the ECML in my upgrade plan).

This layout prevents "up" trains crossing over "down" to the greatest possible extend, as it is GN trains would be required to cross over the lines of the platforms serving the fast line however the trains would atleast be moving in the same direction allowing tighter timing patterns to be carried out safely.

I would also cover the entire station complex in a nice ETFE roof permitting the newly built platforms to do without shelters reducing vandalism potential, as well as signalling the arrival of the "High Speed Era".

 

[Invincibles]

Looking at the map it is going to be hard to get a chord off the line to Ely without demolishing buildings and it all seems a bit expensive.

So at Peterborough I would look to:

Add a further platform to the West, This allows all trains going to Ely to use platforms 5 and 6.

Platform 4 would become northbound ECML only.

Platforms 1,2 and 3 would handle the southbound ECML and the terminating commuter trains. This still needs crossing, but if it is really a problem a flyover somewhere south could be constructed to put the fasts to the west of the slows.

A new flyover would also be added north of Peterborough to allow trains over to platform 5 to head to Ely.

As more freight will be coming from that direction it might be sensible to have avoiding lines between 5 and 6 but really that is a small consideration as they could choose to simply go through the platforms.

A nice roof for the whole thing would be good, but I do not see that as a necessity. The longer term future for Peterborough is going to be as a stop on almost all ECML trains as faster ones will have diverted on the high speed network.

 

[HSTEd]

EDIT:

The flyover actually makes the ECML Up Slow to March line chord unneccesary assuming freight trains can get over it, so Il scrap that part of the plan and keep Platform 1 as a Freight line that can also take trains in the peak, as well as anything from the north that happens to be on the slows, (such as an extension of current GN trains to Stamford or whatever)

 

[Aictos]

Peterborough is an interesting one. How would you lay it out, if you had a fantasy budget and weren't too concerned about the restriction imposed by the bridges over the Nene? Given the following need to be accommodated:
Fast trains not stopping
ECML through trains
Through trains from/to Stamford and beyond to/from March and beyond
Through trains from/to Grantham and beyond to/from March and beyond
Terminating trains from the March line
Terminating trains from the Lincoln line
Terminating GN trains- which need also to be able to access carriage sidings, be they to the north or south in your fantasy layout.

I would buy some land between Platforms 4/5 and Midland Road and use it to provide a new island platform numbered 6/7 with three bi-directional freight loops of 500m which would replace the existing freight lines.

As part of the improvements to the station, I would remodel the station to provide a concourse sited over the platforms which would have step free access to all platforms plus retail outlets this would modelled on something similar to Leeds or Manchester Piccadilly.

This would include toilets and a larger waiting area with seats.

This would also mean a new entrance built on the western side of the station with better connections for buses, taxis and have pick up spaces.

The existing concourse would be refreshed for a more airy view.

Automatic Gatelines would be installed during this time.

North of Peterborough at Werrington Junction, I would have a flyover over the ECML lines put in allowing access to and from the Stamford lines for Lincoln services which would remove the need for these trains to cross the ECML on the level with the Lincoln services using Platforms 6/7 at Peterborough.

 

[Bald Rick]

But your plan is rather more complex than what the WCML modernisation became. You want to build new tunnels, bridges, fly overs, platforms, increase the number of tracks through some sections and provide for tilting trains which, granted, the WCML programmed delivered for less than £10bn. But then you also want to resignal the route to ETCS2 (which means a lot of existing cabs need refitting for ETCS2) as well as raise line speeds to 170mph . The WCML was going for moving block signalling (which is somewhat comparable to ETCS2) and 140mph at a projected cost of £13bn (and that's in 2001 £££s) I think it's perfectly reasonable to assume that £10bn might in fact be an underestimate rather than an overestimate!

Remember that West Coast was mainly a big renewal programme with some incremental upgrades. The capacity upgrades were mainly the Trent Valley 4 tracking, reopening the existing flyover at Nuneaton, an extra track north of Rugby, the new platforms at MK, and some incremental stuff at a few other places. No new flyovers, chord lines, tunnels, etc. etc.

Re East Coast line speeds, anecdotally much of it is aligned for 160mph already. However, track alignment is only one of the 80 odd factors that affect line speed. Aside from cab signalling, going above 125 would need all the OLE replaced, all level crossings removed / bridged, and some serious work to what sits underneath the track. This is particularly so between Peterborough and Huntingdon where the line speed has never been more than 100 for much of the way because the ground conditions are so poor. There would still have to be the existing restrictions through the tunnels and platforms.

A new line sorts all this out from the start. And I really don't think that HS 2 will see a downgrade of the existing ECML services, quite the opposite.

 

[shinkansen1966]

I was rather hoping for the Virgin East Coast high speed line by now. It was going to be ready by 2009.

http://news.bbc.co.uk/1/hi/business/667373.stm

 

[HSTEd]

Whats the minimum distance you have to have between open 125mph lines and track workers?
Would some sort of temporary blast barrier bring it down to a few feet or less? Its just that currently the ECML is mostly through open country, which means theres no particular reason why the second pair of lines has to be right next to the first pair, you could build them 30 feet away behind said barrier and then work using more regular hours.

As for OLE replacement: surely the ECML OLE is due for replacement some time soon? It would certainly need all its feeder equipment rebuilt with autotransformers to cope with the power requirements of faster accelerating trains.

 

[Bald Rick]

As for OLE replacement: surely the ECML OLE is due for replacement some time soon? It would certainly need all its feeder equipment rebuilt with autotransformers to cope with the power requirements of faster accelerating trains.

Most of the GE OLE kit south of Shenfield is approaching its 65th birthday, most of the WCML kit south of Weaver Jn got to 40 (with some now approaching 50) and north of Weaver (same design as ECML) it is almost 40. Apart from certain component changes etc the ECML wires have another 2 decades in them at least.

 

[HSTEd]

What would actually need replacing? the ECML is already fitted with constant tension equipment, so wouldnt you just have to replace the tension weights with heavier ones?

Or is there major structural issue that would prevent simply rewiring at a higher tension, such as the strength of the cantilevers against overturning forces and suchlike.

 

[tbtc]

Apart from certain component changes etc the ECML wires have another 2 decades in them at least.

Would there be a benefit in adding some additional masts on the ECML?