Chiltern electrification alternatives being studied...

[Bletchleyite]

There's nothing saying Chiltern have to take every Class 175 or none of them.

Indeed not, but they're an option - and the presence of them in the franchise agreement makes it clear they are a serious option - to replace both the LHCS and some of the 165s, with others being cut up for parts to allow the ones they keep to be kept going longer.

== Doublepost prevention - post automatically merged: 19 May 2023 ==

And yet it takes about 4km at 125mph on Great Western for the automatic system.

How does this compare to the system Transport for Wales have implemented/are implementing on the Valley Lines to deal with this precise issue?

 

[zwk500]

How does this compare to the system Transport for Wales have implemented/are implementing on the Valley Lines to deal with this precise issue?

Bear in mind that diagram has time not distance on it. I suspect the TfW diagrams looks similar (but in Welsh) and the distances involved are modified appropriately for the Valley lines which are not quite at 125mph.

Given every train would stop at Moor Street and Snow Hill, a Eurobalise in the platform and a warning sign on the Tunnel may well be enough.

 

[Energy]

Bear in mind that diagram has time not distance on it. I suspect the TfW diagrams looks similar (but in Welsh) and the distances involved are modified appropriately for the Valley lines which are not quite at 125mph.

Given every train would stop at Moor Street and Snow Hill, a Eurobalise in the platform and a warning sign on the Tunnel may well be enough.

I agree that between Moor Street and Snow Hill it could work (though you may as well do manual driver changeover to battery and save yourself the hassle of the automatic system).

From what I understand the welsh system looks to be earthing the wire in some sections which reduces the overall (mechanical is still there) clearance by ~180mm iirc. They are using onboard batteries in these sections and the pantograph is not dropped.

Earthing the wire is an option but you require neutral sections at each end and expensive insulated cables to connect either side. You can get similar clearances by using the special insulating paint like in the severn tunnel but that adds to the maintenance upkeep.

 

[Wolfie]

The prohibition against third rail also does not apply to LU four rail systems due to London Underground's differing operational practices, so you could just transfer the line to Aylesbury via Amersham to LU.

Given that will still need work and is hardly likely to make loads of money l trust that £££££s would also be transferred....

== Doublepost prevention - post automatically merged: 19 May 2023 ==

Don't know the specifics but Chiltern have been suffering a shortage of units for some time. 165025 for example has been out of traffic for well over a year.

So how is it that GWR don't seem to be having similar issues or if they are it certainly isn't being publicised?

== Doublepost prevention - post automatically merged: 19 May 2023 ==

There are "democratic" implications about having stations miles outside London where all their services are under the control of the London Mayor and Assembly only. It's already a bit of an issue with the outer Met at the moment, but at least there are alternative Chiltern services as well.

You'd need a way to guarantee that the London Mayor didn't skew the services to benefit his electorate in London over people outside London.

Re your second para, as a Londoner l would want the right not to subsidise those services outside London.

== Doublepost prevention - post automatically merged: 19 May 2023 ==

If you got rid of the Met fasts bi-mode units would only need to have enough battery for the eight or so miles between Aylesbury and Moor Park...

I'm sure that existing Met line users would be ecstatic to have their service hacked to pieces to facilitate Network Rail savings and travellers from outside London. What is in that for TfL?

 

[eldomtom2]

Eight miles from Aylesbury to Moor Park?

Are you saying that's an inaccurate distance?

 

[Bletchleyite]

Are you saying that's an inaccurate distance?

It is yes. It's about 20 miles.

Even Amersham is about 14 or so.

 

[eldomtom2]

I'm sure that existing Met line users would be ecstatic to have their service hacked to pieces to facilitate Network Rail savings and travellers from outside London. What is in that for TfL?

The fasts (as opposed to the semi-fasts) only benefit travellers from outside the borders of Greater London...

It is yes. It's about 20 miles.

Ah sorry, I misspoke. I meant Amersham, not Aylesbury.

 

[The Planner]

Snow Hill Tunnel is where it's worth spending the money to electrification. Discontinuous OLE might be worth it for Old Hill Tunnel as trains will have a bit of a run up on the juice anyway. I think permanently earthed sections are sensible where clearances don't allow and the bridge rebuild would be silly money, but if you're getting longer stretches of no wires then you have to ask whether the battery solution might be better overall anyway.
Permanently earthed sections would also help with the pan up/down issue as you can just use APS magnets. But otherwise APCO exists and is fine for the Bi-Modes so why not Pan-Battery operation?

Its 1 in 51 on the run up and 1 in 81 in the tunnel. Its a bit steep.

 

[JonathanH]

So how is it that GWR don't seem to be having similar issues or if they are it certainly isn't being publicised?

They are having the same problems with 166s unavailable in the Bristol area while parts are moved to other units.

 

[Energy]

I think permanently earthed sections are sensible where clearances don't allow and the bridge rebuild would be silly money, but if you're getting longer stretches of no wires then you have to ask whether the battery solution might be better overall anyway.

Permanently earthed sections require a neutral section either side and expensive insulated cables to connect either side. You get similar clearances by using the special insulating paint but without these issues.

Permanently earthed sections would also help with the pan up/down issue as you can just use APS magnets. But otherwise APCO exists and is fine for the Bi-Modes so why not Pan-Battery operation?

Again APCO takes a long time. It works for bimodes but it should really be used for long sections of the journey off wires like it is on Great Western not for dropping at every tricky bridge.

 

[12LDA28C]

So how is it that GWR don't seem to be having similar issues or if they are it certainly isn't being publicised?

== Doublepost prevention - post automatically merged: 19 May 2023 ==

I believe they are, as @JonathanH described.

 

[Mikey C]

Indeed not, but they're an option - and the presence of them in the franchise agreement makes it clear they are a serious option - to replace both the LHCS and some of the 165s, with others being cut up for parts to allow the ones they keep to be kept going longer.

The 175s could displace some of the 168s to take over the 165 operations along the mainline, with the remaining 165s confined to the Amersham services. Removing the 75mph 165s from the mainline would simplify timetabling as well.

 

[zwk500]

Its 1 in 51 on the run up and 1 in 81 in the tunnel. Its a bit steep.

Presuming that's for Old Hill? You'd need batteries in case of an emergency stop in the tunnel anyway, if you did go down the discontinuous route.

 

[Wolfie]

They are having the same problems with 166s unavailable in the Bristol area while parts are moved to other units.

Ah, ok, thanks.

 

[JonathanH]

The Chiltern Line gets two mentions in the North West and Central CP7 Strategic Business Plan, the second of those to note that it is of secondary importance to other routes. Life extension of some signalling at Marylebone and some work on the trainshed.

While obviously enhancement is a matter for the DfT and not Network Rail, you can see where the ideas of 'electrification alternatives' come from.

 

[Basil Jet]

I'd tend to agree with other posters that while High Wycombe is a good idea (allows a high frequency metro-style service to run),

Not without 3- or 4-tracking from Wembley Stadium to South Ruislip or somewhere...

 

[nw1]

Not without 3- or 4-tracking from Wembley Stadium to South Ruislip or somewhere...

I guess I meant "relatively high frequency" e.g. 15-min, rather than a LU/LO type service.

If there's 2tph to Birmingham and 2tph to Oxford (diesel) on a 15-min pattern, perhaps you could get 4tph stoppers to High Wycombe leave immediately behind them, particularly as they will be EMUs (and thus presumably fast accelerating) and particularly also if a skip stop pattern is employed where only the larger stations get all 4tph stopping, e.g. 2tph call at the small Greater London stations and the other 2tph call at the small Bucks stations like Denham. I don't know though.

In fact I'm fairly sure the old Chiltern peak (pre Covid) used to employ this kind of skip-stopping to produce a very frequent peak service.

But even if not, at least a half-hourly stopping EMU to High Wycombe would be a start.

 

[Class172]

Ah, ok, thanks.

The reason perhaps that the situation is not so obvious at GWR is probably because they have much greater variety in their fleet and as such can chuck out a replacement unit to cover it. For example if a 166 fails in Devon, a 158 might be put out in its place, and in turn an HST might cover the mainline diagram. That’s not to say however that the 158s are without parts issues themselves.

 

[Wolfie]

The reason perhaps that the situation is not so obvious at GWR is probably because they have much greater variety in their fleet and as such can chuck out a replacement unit to cover it. For example if a 166 fails in Devon, a 158 might be put out in its place, and in turn an HST might cover the mainline diagram. That’s not to say however that the 158s are without parts issues themselves.

TY.

 

[RobShipway]

Admittedly, it may depend on the trains that are used to replace the Chiltern class 165/168 units. But if the route was electrified from say from Neasden South Junction or Wembley Stadium station northwards, surely if Battery/Electric trains are used, it could power by battery into Marylebone and fast recharge between services at Marylebone if OHLE was able to be setup at Marylebone?

 

[Energy]

Admittedly, it may depend on the trains that are used to replace the Chiltern class 165/168 units. But if the route was electrified from say from Neasden South Junction or Wembley Stadium station northwards, surely if Battery/Electric trains are used, it could power by battery into Marylebone and fast recharge between services at Marylebone if OHLE was able to be setup at Marylebone?

Is Wembley to Marylebone particularly difficult? If not then why go for battery there?

 

[zwk500]

Is Wembley to Marylebone particularly difficult? If not then why go for battery there?

You have the St Johns Woods tunnels under Lord's, which may or may not be problematic.

 

[RobShipway]

Is Wembley to Marylebone particularly difficult? If not then why go for battery there?

You have the St Johns Woods tunnels under Lord's, which may or may not be problematic.

I believe either earlier in this thread or in another thread, someone was stating that it is very unlikely that electrification could be setup through the St Johns Woods tunnels. Hence the need to go battery or have an alternative power other than diesel as many people in the area south of Neasden have complained about diesel engine noise and pollution.

 

[AJDesiro]

You have the St Johns Woods tunnels under Lord's, which may or may not be problematic.

Is there no way in which you could lower the track, if tunnels are that much of an issue?

 

[zwk500]

Is there no way in which you could lower the track, if tunnels are that much of an issue?

Slab track would enable you to lower the height, depending on the structure shape. It may also be possible to dig the earth out.

 

[Snow1964]

You have the St Johns Woods tunnels under Lord's, which may or may not be problematic.

There are double tunnels, since construction, to avoid digging up the Lords practice area twice (it was done over a winter) they built the extra tunnels needed to quadruple the line at time of construction.

The question is can one of the tracks be skewed into the spare tunnel.

 

[t_star2001uk]

The spare tunnel at the Marylebone end does not go very far. The end AFAIK is under what is now the site of the Wellington Hospital so it would be quite a project to complete....

 

[12LDA28C]

Is there no way in which you could lower the track, if tunnels are that much of an issue?

Really? And then what do you do with the section in between the two tunnels where the Chiltern line passes over the WCML?

 

[Bletchleyite]

Really? And then what do you do with the section in between the two tunnels where the Chiltern line passes over the WCML?

Trains can go up and down hills.

 

[12LDA28C]

Trains can go up and down hills.

So you're suggesting lowering the track at the start of the tunnel because that's an easier and cheaper option, then raising the roof of the tunnel at the other end to be at the necessary height to pass over the WCML.