ECML capacity improvements

[Aictos]

You could easily purchase a bit of the car park to get extra width. The leisure park buildings are miles away.

Very true, although it might be wise to construct it as a 12 car platform as it saves on possible extensions later and means all platforms would be capable of taking 12 cars, the new platform being single faced but capable of becoming a though line.

With this potential platform, a new line from Langley Junction to the platform should be constructed together with pointwork closer to Langley Junction enabling access onto and off the Hertford line from the Fasts and vice versa which would mean diversions would no longer be restricted to just platforms 1 and 4 meaning better use of capacity is used and with all Letchworth/Stevenage terminators now terminating at Stevenage, it offers better connections to other services, let's face it the connections at Hitchin and Letchworth are more then capable of being met at Stevenage plus there are more things available in Stevenage!

 

[jopsuk]

Cambridge*3
....
*3 Platforms 1 and 4 only

Pretty sure Cambridge platform 4 is actually 10 cars (by the sign at the far end of it!) though there's plenty of space beyond the end, before the tracks to 5 and 6 join, to extend it outwards.

As far as 12 car trains go, from Cambridge this is currently the 0715 and 0745services. The 0715 comes as a four car from Ely, the 0745 a four car from Kings Lynn. They attach to a further eight carriages that are already waiting in Platform 1. Both call at Royston (the non-stop trains don't start until 0920). There's no 12 car evening services to Cambridge currently. That's still a heck of a lot of carriages leaving Cambridge for London between 0700 and 0800- there's two further FCC services (both 8 car I think) and four NXEA 9which I think are all 8 as well). They still get overcrowded.

 

[philjo]

Once the Hitchin flyover is built, the Hertford services that terminate at Stevenage can easily run on to Letchworth & reverse there in the sidings, as they will have no impact on the ECML fast lines. This would restore more through services to Hertford from Hitchin/Letchworth. The current connections at Stevenage are terrible, particularly southbound.
At the moment, it causes conflicts over the junction at Hitchin northbound without a long wait.

Likewise, once Letchworth is extended to 12 car they could possibly split some services there (i.e the rear 4 coaches would call all stations as Meldreth-Foxton platforms are only 4 cars) without delaying anything on the main ECML itself.

 

[jopsuk]

Letchworth is an interesting one- am I right in thinking that whilst clearly built to be a four track station, it's only ever had the current two? Even the bridge at the west end has spans for the additional lines, and both platforms are accessed from the footbridge.

 

[philjo]

Yes, that is correct.
The station was designed for 4 tracks (2 island platforms) when it opened in 1913 but to date only 2 tracks have been used. The road bridge was built about the same time.
The platforms are therefore very wide & currently back onto hedging/trees etc. It would be therefore feasible to install an extra usable platform on the down side which could be used for terminators to use & either turn back from there or run on into the existing sidings without affecting other traffic & the return working starting from the current platform 1 as per the current arrangements.
Thinking in particular of the extra services that would probably use this line once the Thameslink project is complete plus potential east-west rail services that may make an extra platform at Letchworth useful to be able to let a fast service overtake a stopper/connect with each other without holding ECML services up if it was done at Hitchin or Stevenage.

The station is in a cutting with the footbridge being the level of the street outside. The lifts haven't been used for 20 years or so (though hopefully this situation may change soon as part of the platform lengthening)
The platform canopies are 3 coaches long.

 

[LE Greys]

Yes, that is correct.
The station was designed for 4 tracks (2 island platforms) when it opened in 1913 but to date only 2 tracks have been used. The road bridge was built about the same time.
The platforms are therefore very wide & currently back onto hedging/trees etc. It would be therefore feasible to install an extra usable platform on the down side which could be used for terminators to use & either turn back from there or run on into the existing sidings without affecting other traffic & the return working starting from the current platform 1 as per the current arrangements.
Thinking in particular of the extra services that would probably use this line once the Thameslink project is complete plus potential east-west rail services that may make an extra platform at Letchworth useful to be able to let a fast service overtake a stopper/connect with each other without holding ECML services up if it was done at Hitchin or Stevenage.

The station is in a cutting with the footbridge being the level of the street outside. The lifts haven't been used for 20 years or so (though hopefully this situation may change soon as part of the platform lengthening)
The platform canopies are 3 coaches long.

Certainly sounds right, probably partly as a result of Ebernezer Howard persuading the GNR to allow for growth (he got so many things right). I was originally thinking along the lines of a bay, but a through platform would give access to the sidings, of course. The one concern about splitting trains is that it would cut down the potential links between certain stations (Letchworth-Welwyn, etc) but that's unlikely to be handled too badly. Probably, what will happen is that the peak-time fasts, first stop Letchworth, will drop off four coaches there to give Baldock, Ashwell and Royston a faster link to London. That could mean that one current service to Royston would divert up to Peterborough to give Arlesey, Biggleswade and Sandy a half-hourly peak service (currently it cuts back to hourly in the peak). All-in-all, good plan.

 

[stut]

That could mean that one current service to Royston would divert up to Peterborough to give Arlesey, Biggleswade and Sandy a half-hourly peak service (currently it cuts back to hourly in the peak). All-in-all, good plan.

Unless I'm misunderstanding... Arlesey, Biggleswade and Sandy currently get a half-hourly fast service in the peak (plus a handful of very popular non-stops from Biggleswade to King's Cross). The off-peak service is one fast (not Arlesey), one all-to-Potters-Bar.

While you do get a good number of people leaving these peak services at Hitchin, I think you'd be hard pressed to fit the remainder into a 4-car.

 

[Aictos]

Stut:

The FCC Peterborough FCCs consist of two basic stopping patterns with a limited number of alterations which is:

Peterborough then all stations to Stevenage, Finsbury Park and Kings Cross.
Peterborough then all stations to Hatfield, Potters Bar, Finsbury Park and Kings Cross.

None of the Peterboroughs call at Brookmans Park, Welham Green etc... as these stops are catered for by the Welwyn stoppers.

 

[LE Greys]

Unless I'm misunderstanding... Arlesey, Biggleswade and Sandy currently get a half-hourly fast service in the peak (plus a handful of very popular non-stops from Biggleswade to King's Cross). The off-peak service is one fast (not Arlesey), one all-to-Potters-Bar.

While you do get a good number of people leaving these peak services at Hitchin, I think you'd be hard pressed to fit the remainder into a 4-car.

I've been doing a bit of further consideration here. The idea was that the 16:44 KGX-CBG fast would still run non-stop to Letchworth, then drop four coaches to form a Letchworth-Royston all-stations. The 17:22 KGX-CBG would then divert to Peterborough, but would be covered by the 17:23 KGX-ROY (which doesn't stop at Hitchin) also splitting at Letchworth and the front portion extending to Cambridge. I haven't worked it out properly yet, and there seems to be a problem with a loss of links from Potter's Bar, Hatfield, the Welwyns and Knebworth to Cambridge line stations. However, it's astonishing just how many trains miss Potter and Hatfield anyway.

There also seems to be a place for coupling some up trains from Royston to those Cambridge fasts that stop at Letchworth, then running them as 12-car to King's Cross. This saves a path for something. Ideally, that ought to be a service in from Lincoln, but this isn't an ideal world.

 

[Bald Rick]

There is a low cost option for the Welwyn 2 track 'bottleneck'. Close Welwyn North station in the peak.

Hey presto! another 2 or even 4 paths each way. Saves a couple of hundred million quid for the loss of about £2m pa ticket revenue at worst. Most of the 5-600 people who commute from Welwyn North could get to WGC easily anyway.

That's a cunning plan. But it will never happen.

 

[MidnightFlyer]

There is a low cost option for the Welwyn 2 track 'bottleneck'. Close Welwyn North station in the peak.

Hey presto! another 2 or even 4 paths each way. Saves a couple of hundred million quid for the loss of about £2m pa ticket revenue at worst. Most of the 5-600 people who commute from Welwyn North could get to WGC easily anyway.

That's a cunning plan. But it will never happen.

How hard would it be to four-track after the viaduct to Knebworth? Woulkd be complex south through Welwyn North, but may allow a couple more paths per hour. Also, even if its big then, this isn't fully about the peak hours, it a pain atb the rest of the time too

 

[jon0844]

That's a cunning plan. But it will never happen.

I suspect there are a lot of quite rich, powerful AND influential passengers using that station every single day - so you're right, it won't happen!

WGC has ample parking (well, so does Welwyn North given the hike in charges and people blocking nearby roads) and a ticket from there is cheaper, and indeed has more services (consider the slows running every 20 minutes for a lot of the day, and the fact a lot of people work in the City) but I am still sure people would go mad.

 

[Lee_Again]

Nevertheless, it would probably be cheaper to pay for taxis for every passenger, or offer free parking at WGC, than to build a new viaduct and tunnels.

Realistically, closing Welwyn North is not an option. And anyway, the little coffee shop is excellent!

I suspect 12 coach FCC and joining 180's is far easier and cheaper.

just done the maths...

500 taxis * £5 (to WGC) = £2,500 * 2 (from WGC) = £5,000 per day

assume new viaduct and tunnels = £2bn

so £2,000,000,000 / £5000 = 400,000 days of taxis

400,000 days / 365 days = (well)over 1000 years

 

[DaveNewcastle]

How hard would it be to four-track after the viaduct to Knebworth? Woulkd be complex south through Welwyn North . . . .

. . .and would be very expensive quadrupling through the mile which is in a couple of two-track tunnels.

 

[MidnightFlyer]

. . .and would be very expensive quadrupling through the mile which is in a couple of two-track tunnels.

Oh yeah, forgot about the north tunnels, what about just putting the down on a loop, there's enough room

 

[stut]

Stut:

The FCC Peterborough FCCs consist of two basic stopping patterns with a limited number of alterations which is:

Peterborough then all stations to Stevenage, Finsbury Park and Kings Cross.
Peterborough then all stations to Hatfield, Potters Bar, Finsbury Park and Kings Cross.

None of the Peterboroughs call at Brookmans Park, Welham Green etc... as these stops are catered for by the Welwyn stoppers.

Ah yes, I always forget those two. The faster one tends not to call at Arlesey during the week, also.

However, the point was that the slower service doesn't run in the peaks, with the faster one running twice hourly. There's also a super-fast service that tends to be fast from St Neots when 12-car or Biggleswade when 8-car (some exceptions).

Trust me, I know the peak service far, far too well!

 

[Fred26]

Oh yeah, forgot about the north tunnels, what about just putting the down on a loop, there's enough room

Apparently the line going north into Knebworth used to change to four-track a bit further south than it does at the moment. It can only be a few hundred metres though, so it's debatable whether moving the points further south would actually achieve anything.

 

[LE Greys]

Apparently the line going north into Knebworth used to change to four-track a bit further south than it does at the moment. It can only be a few hundred metres though, so it's debatable whether moving the points further south would actually achieve anything.

There also used to be loops through Welwyn North, possibly to allow for a bit of operational flexibility in allowing expresses to pass goods trains (which were a lot slower then). However, it took quite a long time to clear the signals after a train entered the loop, and they ultimately turned out to be pretty much useless.

 

[Aictos]

Pity the loops got removed, could have used them tonight with the disruption!

 

[Tomnick]

Loops at Welwyn North nowadays would be next to useless, probably even in times of disruption. A train which stops at Welwyn North, costing it say 3 minutes, is only going to occupy two 'fast' paths between Digswell and Woolmer Green. If you loop that train at Welwyn North instead, it'll still occupy two 'fast' paths (one as it enters the loop, followed by an extended dwell as something else runs past, then a second path as it leaves the loop). In fact, you might lose an extra minute (which could equate to an additional path if everything's timed on tight headways?) if it's subject to approach control into the loop. So there's no benefit to be had from looping stoppers on such a short section of double track, but still the cost of a significant extension to journey times on the stopper.

Loops make more sense on longer sections of double track (Hertford Loop, for example), where a stopper effectively occupies a much greater number of 'fast' paths (picture the graph, with a large 'window' following the departure of the stopper where no fast train can operate without catching up with it. Even then though, long 'dynamic' loops covering a couple of station stops must be preferable, to avoid the long wait in the loop that'd otherwise result.

 

[tbtc]

Nevertheless, it would probably be cheaper to pay for taxis for every passenger, or offer free parking at WGC, than to build a new viaduct and tunnels.

Realistically, closing Welwyn North is not an option. And anyway, the little coffee shop is excellent!

I suspect 12 coach FCC and joining 180's is far easier and cheaper.

just done the maths...

500 taxis * £5 (to WGC) = £2,500 * 2 (from WGC) = £5,000 per day

assume new viaduct and tunnels = £2bn

so £2,000,000,000 / £5000 = 400,000 days of taxis

400,000 days / 365 days = (well)over 1000 years

In fairness, you wouldn't need a separate taxi for every passenger. Set up a shuttle bus for when each train arrives - much simpler.

 

[EWS 58038]

I think a bit of investment is the only solution to get the ECML up to standards.

In my opinion this should include:
- Building a second Welwyn viaduct
- Dig your way through that piece of rock that comes after it
- Get rid of Woolmer green Jn

One might argue that "such a piece of concrete will destroy the valley"

Well, in that case one could build a replica of the current viaduct so the view won't get spoiled more then today. But this comes at a surplus.

I think all can be done under 750 million but be worth over 2 billion to the treasury over 60 years.

 

[LE Greys]

This probably isn't possible, but the ideal would be to separate out the fast lines, making it possible to upgrade to 140 all the way from Hatfield to Holme (with restrictions through Stevenage, Biggleswade and possibly Offord). This would mean two extra bores for each tunnel rather than one, to avoid having a potential 280 mph pressure wave interaction, and a new viaduct parallel with the old but a good bit stronger. It would also mean some expensive alterations to Welwyn Garden City, and might result in some very extended blockades, but would produce the ideal result.

 

[philjo]

I seem to remember that Roger Ford once suggested in Modern Railways to construct an extenstion of the down slow from Digswell over to Welwyn North by means of a cantilever bridge on the side of the viaduct (this side not being the view that EH wanted to protect).
This would lead into a bay platform in part of the present car park.
The line would be bidirectional from WGC & alternate Mooorgate-WGC stoppers would then extend along this line to Welwyn North & reverse.
it would pass the next service at WGC platforms 3/4 before crossing over the flyover.

During peak times the through platforms would then not be used for stopping trains i.e. in the morning nothing southbound stops & nothing northbound in the evening but contra-peak & off-peak services can still call.

It isn't a complete solution but no need to do anything with the tunnels which reduces the cost (unless you also extend that 3rd line through to Knebworth for use by stopping services with a flyover at the other end)

 

[Peter Mugridge]

This would mean two extra bores for each tunnel rather than one, to avoid having a potential 280 mph pressure wave interaction.

Would this really be a problem when the North Downs Tunnel and others on HS1 outside the London single bores are able to pass two 186mph Eurostars?

 

[LE Greys]

Would this really be a problem when the North Downs Tunnel and others on HS1 outside the London single bores are able to pass two 186mph Eurostars?

Yes, but (A) it's huge, and (B) it only ever has to deal with pressure-sealed passenger trains. Watford Tunnel has two lines fully-capable of 125 mph, but the pressure-sealed Pendys pass through it at 115, in case a non-sealed train is coming the other way.

 

[Peter Mugridge]

Yes, but if you're going to build a new tunnel anyway you might as well make it a large enough single bore rather than two smaller bores?

 

[swt_passenger]

Yes, but if you're going to build a new tunnel anyway you might as well make it a large enough single bore rather than two smaller bores?

There may be constraints in how the existing tracks are used. If the additional tracks have to be slows either side of the existing that became fasts, they could be left with no option other than separate single bores.

 

[LE Greys]

There may be constraints in how the existing tracks are used. If the additional tracks have to be slows either side of the existing that became fasts, they could be left with no option other than separate single bores.

That's the main reason I think that the existing lines should become the slows (if it's possible).

 

[Peter Mugridge]

If the existing tunnel becomes the fasts, it could always be re-bored....

Yes, I know, that's as much £££ as a totally new tunnel so it doubles the cost of the tunneling part...