Could Chiltern Electrify with third rail?

[Bald Rick]

Ahh, I didn't actually know that! I knew OLE/3rd rail was difficult to mix, but OLE/4th Rail being easier to undertake does improve the business case a little bit for wiring the Chiltern.

Yes, the issue with having the AC and 3rd rail together is about the return currents in the running rails. In the 4th rail system, the ‘return’ current is in the 4th rail, and the running rails could easily take the AC return current (with suitable bonding).

 

[Bald Rick]

The Chiltern lines go over OHLE at South Hampstead & West Hampstead, with the High Wycombe route going over OHLE at Wembley as well, & the Aylesbury route going over OHLE at Kenton.
That would suggest that suitable power supply infrastructure for 25kV isn't very far away.

The infrastructure isn’t far away, but that doesn’t mean it has the capacity to feed the Chiltern. Indeed I think it is very unlikely to do so. And in any event, you would want a separate power supply so that you don’t lose the Chiltern and WCML together in the event of one feeder going off line.

 

[hwl]

Indeed I think it is very unlikely to do so. And in any event, you would want a separate power supply so that you don’t lose the Chiltern and WCML together in the event of one feeder going off line.

Simplified to - It doesn't

 

[Bald Rick]

Simplified to - It doesn't

Just leaving a bit of wriggle room

 

[mr_jrt]

Chesham does still remain an enigma...not sure how many commuters from the 3rd biggest town in Bucks would react to losing their direct link to the Square Mile in the peaks...

They change just like they did for years -the tail cannot wag the dog. They can change to the Met at HotH, assuming Chiltern run a through service from Chesham.

That being said, there does seem to be enough room along most of the route to have a 4-track formation, with the Fast lines self-contained (based off a quick sweep with Google Maps), similar to the situation with c2c and the District line east of Bow Road. The only problems seem to be a few spots near Rickmansworth (the bridge over Rectory Road), and each station itself. If a self-contained route were to be made for Chiltern, electrification at 25kV could become viable.

The original upgrade plan in the 50's and 60's was for Rickmansworth station to be rebuilt to the east, roughly next to where Waitrose is now, IIRC. This sidesteps the bridge issue nicely as I don't think a case could be made for four-tracking the whole route to Chesham, let alone Aylesbury.

 

[The Planner]

Indeed.

Snow Hill electrification will happen. That's another end point.
[ There is increasing pressure to get diesel, & other fuels, out of urban areas. Majority of the services are commuter/local, which EMUs are perfect for.
Snow Hill, Moor St, Jewellery Quarter & Bordesley are all in the new Birmingham Clean Air Zone. Rail isn't impacted by that, yet. Snow Hill - Stourbridge is very urban. So is Snow Hill - Solihull.
Stock on the WMR services is 10 years old, Chiltern is 20 years old. XC is 20 years old. It will need replacing at some point. ]

Not anytime soon it won't. The rolling stock will likely be replaced before wires go up.

East-West Rail, if/when it gets built, will be electrified with OHLE. Oxford, Bletchley & Bedford are already done that way.
So, that's either services they will run, or services & infrastructure that directly connect with the existing Chiltern lines.

Again, E-W won't open with OHLE, and it will be a long time before any gets put up along it.

 

[Dr Hoo]

Clapham and the King's Cross fire both predate HSE taking on HMRI don't they?

I thought that only occured in 1990.

In the interests of complete accuracy I am happy to confirm that you are correct about 1990. I was more thinking about the change in 'approach' to railway safety that (as I saw it) sprang from the retirement of the last of the old ex-military Chief Inspectors (Major Rose) in 1988 and his succession by an HSE person in the shape of Robin Seymour. The very lengthy and 'adversarial' investigations into both Clapham and King's Cross meant that the application of lessons from these (and subsequent) accidents were dominated by generalist safety thinking rather than one attuned to the special features of railways.

 

[Energy]

I see 3rd rail for Chiltern being unlikely, it takes enough people to agree that 3rd rail is fine to get funding and I don't think many people think 3rd rail is safe enough for large new installations. People also seem to be forgetting that the line is used by other operators, GWR, WMR and XC.

• GWR's 387s can be used on 3rd rail or OHLE so GWR is fine.
• WMR's is getting new aventras, they could order more for snow hill services and get them fitted with 3rd rail equipment but they probably don't want to for maintanence purposes.
• XC currently have diesel only trains but are probably going to get bimodes (likely 802s or a proposed bimode aventra) these could be fitted with 3rd rail equipment in the case of the aventra, with the at300s, the 395 has 3rd rail which isnt at300 but is similar. However does the next XC operator really want to use tri mode units, probably not.

Most of the operators, with the exception of GWR as they already have 3rd rail equipment, could use 3rd rail on Chiltern, although the probably don't want to and would much prefer to use OHLE, 3rd rail also limits future operations as most trains don't have 3rd rail fitted.

 

[option]

Not anytime soon it won't. The rolling stock will likely be replaced before wires go up.

Again, E-W won't open with OHLE, and it will be a long time before any gets put up along it.

What timeframe is "soon".
I haven't said that it's happening tomorrow, or even in the next few years, simply that it will happen.

If you can get another 20 years out of the XC, & some of the Chiltern, stock by refurbing it, then that gets you to 2040. That's when new petrol & diesel cars wont be available, & that could be bought forward. No gas heating for new build homes from 2025.
Good luck ordering new DMU's at that point, if their are even any designs available.
If bi-modes have been proven to work & be reliable, then maybe XC & Chiltern will be having them. Whether new ones or cascades, they will want wires.

 

[The Planner]

Snow Hill? not in the next decade as a minimum. Possibly CP8 which is 2029-34.

 

[Meerkat]

This is all a bit hypothetical without knowing what the clearances are like on Chiltern. They look low, and are assumed to be too low, but how bad is it really?
Presumably the tunnels are the most likely to be showstoppers if they would need long blocks to fix?

 

[MarkyT]

This is all a bit hypothetical without knowing what the clearances are like on Chiltern. They look low, and are assumed to be too low, but how bad is it really?
Presumably the tunnels are the most likely to be showstoppers if they would need long blocks to fix?

It might be possible to justify ground level DC electrification on the highly segregated tunnel section into Marylebone and where the Chiltern tracks share the corridor with the Met and Jubilee as far as Amersham, but soon after diverging from this corridor at Neasden, and north of Amersham, a transition to OHLE (of whatever voltage) would be a likely requirement.

 

[Bald Rick]

It might be possible to justify ground level DC electrification on the highly segregated tunnel section into Marylebone and where the Chiltern tracks share the corridor with the Met and Jubilee as far as Amersham, but soon after diverging from this corridor at Neasden, and north of Amersham, a transition to OHLE (of whatever voltage) would be a likely requirement.

If clearances are a problem, and I doubt they are too bad, then batteries will be the answer. Almost certainly cheaper than all the D.C. substations and switchgear necessary for A short D.C. section, almost certainly more reliable, useful elsewhere (e.g. if Snow Hill Tunnel is an issue), and also gives a useful recovery / ‘get you through’ facility if the OLE is off on any section for any reason.

 

[MarkyT]

If clearances are a problem, and I doubt they are too bad, then batteries will be the answer. Almost certainly cheaper than all the D.C. substations and switchgear necessary for A short D.C. section, almost certainly more reliable, useful elsewhere (e.g. if Snow Hill Tunnel is an issue), and also gives a useful recovery / ‘get you through’ facility if the OLE is off on any section for any reason.

I don't disagree with that, perhaps with some charging points in the terminus platforms for topping up while loading. The stationary charging points could use conductor rails and shoes compatible with LUL's 4 rail system (as with Vivarail's fast charger concept), so power could also be drawn from the traction rails on the shared LUL owned sections of the Aylesbury route north of Harrow without erection of OHLE. I think there's also a good case to extend the 4-rail system south of Harrow to Neasden or Finchley Road. Primarily for staff safety, From Finchley Road onwards I would rather not have any ground level power in the tunnels, or in the station yard area of the terminus (apart from for the stationary charging points). In a notional whole fleet renewal, an inner suburban unit might be specified with 4-rail and OHLE pickup and a moderate battery capacity to operate Aylesbury and High Wycombe stoppers. For longer distance limited stop services to the Midlands and Oxford, AC electric or diesel units would be used (or bimode as appropriate to the extent of electrification), with sufficient battery storage on board to power all the way from the end of wiring or permitted diesel operation (say around Neasden), into and back out of Marylebone.

 

[Bald Rick]

I don't disagree with that, perhaps with some charging points in the terminus platforms for topping up while loading. The stationary charging points could use conductor rails and shoes compatible with LUL's 4 rail system (as with Vivarail's fast charger concept), so power could also be drawn from the traction rails on the shared LUL owned sections of the Aylesbury route north of Harrow without erection of OHLE. I think there's also a good case to extend the 4-rail system south of Harrow to Neasden or Finchley Road. Primarily for staff safety, From Finchley Road onwards I would rather not have any ground level power in the tunnels, or in the station yard area of the terminus (apart from for the stationary charging points). In a notional whole fleet renewal, an inner suburban unit might be specified with 4-rail and OHLE pickup and a moderate battery capacity to operate Aylesbury and High Wycombe stoppers. For longer distance limited stop services to the Midlands and Oxford, AC electric or diesel units would be used (or bimode as appropriate to the extent of electrification), with sufficient battery storage on board to power all the way from the end of wiring or permitted diesel operation (say around Neasden), into and back out of Marylebone.

I think equipping all the putative Chiltern fleet with 4R kit, and all the additional gubbins required in the electronics, as well as batteries, would be a complete waste of money. You’d just need the batteries. Stadler have trains out there now capable of 50 miles off the wire, I’m sure they could manage Finchley Road to Marylebone and back!

I agree some form of charging at Marylebone is desirable, however very simple OLE at 25kV off headspans would be possible, as the trains wouldn’t be moving. The issue will be getting the power there - about 10MW should do - but that would be the same whatever the current collection system. It would of course be cheaper (in terms of distribution) to supply the power in AC.

 

[MarkyT]

I think equipping all the putative Chiltern fleet with 4R kit, and all the additional gubbins required in the electronics, as well as batteries, would be a complete waste of money. You’d just need the batteries. Stadler have trains out there now capable of 50 miles off the wire, I’m sure they could manage Finchley Road to Marylebone and back!
I agree some form of charging at Marylebone is desirable, however very simple OLE at 25kV off headspans would be possible, as the trains wouldn’t be moving. The issue will be getting the power there - about 10MW should do - but that would be the same whatever the current collection system. It would of course be cheaper (in terms of distribution) to supply the power in AC.

Ideally electrification with OHLE should reach all the way to Marylebone. If it won't fit, the long distance / High Wycombe local fleet needs to be able to reach and return from the terminus on battery, without having to start any bimode engines within the CAZ. For these trains, I agree 4-rail power compatibility is not relevant. Aylesbury line trains will need both systems to take advantage of existing DC electrification, with OHLE beyond Amersham and for Marylebone approaches. I'm a supporter of batteries on most trains, even those that spend all their time on electrified networks, for all the self rescue, planned isolation and diversionary benefits they offer. On board batteries might also have some merit as a performance reserve if supply voltage on a DC network starts to drop significantly under peak load.

 

[The Planner]

Chiltern are doing 165 hybrid trials anyway I believe.

 

[Bald Rick]

Ideally electrification with OHLE should reach all the way to Marylebone. If it won't fit, the long distance / High Wycombe local fleet needs to be able to reach and return from the terminus on battery, without having to start any bimode engines within the CAZ. For these trains, I agree 4-rail power compatibility is not relevant. Aylesbury line trains will need both systems to take advantage of existing DC electrification, with OHLE beyond Amersham and for Marylebone approaches. I'm a supporter of batteries on most trains, even those that spend all their time on electrified networks, for all the self rescue, planned isolation and diversionary benefits they offer. On board batteries might also have some merit as a performance reserve if supply voltage on a DC network starts to drop significantly under peak load.

Aaylesbury line trains don’t need to take advantage of the D.C. - use the batteries. It’s only 15 miles (and downhill on the way in )

 

[Bald Rick]

Chiltern are doing 165 hybrid trials anyway I believe.

Energy recovery - roughly equivalent to a Toyota Prius.

 

[option]

I think equipping all the putative Chiltern fleet with 4R kit, and all the additional gubbins required in the electronics, as well as batteries, would be a complete waste of money. You’d just need the batteries. Stadler have trains out there now capable of 50 miles off the wire, I’m sure they could manage Finchley Road to Marylebone and back!

I agree some form of charging at Marylebone is desirable, however very simple OLE at 25kV off headspans would be possible, as the trains wouldn’t be moving. The issue will be getting the power there - about 10MW should do - but that would be the same whatever the current collection system. It would of course be cheaper (in terms of distribution) to supply the power in AC.

There's a massive substation site just north of the canal on Lodge Rd, which apparently is a National Grid 400kV connection site.
Run the OHLE from tunnel into station, that's 500metres to platform ends. So all the way into the station, whilst stood at the platform, & acceleration out, can all be done with a power supply.
(if the tunnels are an issue)

That 50miles off wire isn't enough to get you to Oxford (~67miles)
Electrifying to Neasden cuts that to ~62miles, & covers both Chiltern routes.

If East-West rail (Oxford to Bletchley) was sorted & wired, it's then only 50miles from Neasden to Bicester.

 

[Andyjs247]

This is all a bit hypothetical without knowing what the clearances are like on Chiltern. They look low, and are assumed to be too low, but how bad is it really?
Presumably the tunnels are the most likely to be showstoppers if they would need long blocks to fix?

Who is assuming the clearances are low? The Class 165s are some of the largest stock and don’t have any issues on the Chiltern routes.

 

[Bald Rick]

There's a massive substation site just north of the canal on Lodge Rd, which apparently is a National Grid 400kV connection site.
Run the OHLE from tunnel into station, that's 500metres to platform ends. So all the way into the station, whilst stood at the platform, & acceleration out, can all be done with a power supply.
(if the tunnels are an issue)

That 50miles off wire isn't enough to get you to Oxford (~67miles)
Electrifying to Neasden cuts that to ~62miles, & covers both Chiltern routes.

If East-West rail (Oxford to Bletchley) was sorted & wired, it's then only 50miles from Neasden to Bicester.

Perhaps I’ll explain again. This is an intensively worked line. There shouldn’t be anything particularly difficult about wiring it, however, if St John’s Wood tunnel is a problem, then battery hybrids are the answer. But you don’t particularly want to have 10 tonnes+ of battery on board every unit on a big fleet for cost reasons; generally speaking the smaller the battery the better. Yes you can have a 50 mile range, and no doubt further soon, but the economic case will be a factor of the cost trade off between wiring and batteries for a given fleet on a given section of track.

For Chiltern, I would expect that rpequipping the whole fleet with smallish batteries for a 20 mile range would be plenty. This would need wires most of the way from Finchley to Moor Street.

Who is assuming the clearances are low? The Class 165s are some of the largest stock and don’t have any issues on the Chiltern routes.

AIUI, they are fat, but not particularly tall.

 

[brad465]

Is it possible that if the Chiltern Mainline achieved full electrification between Marylebone and Birmingham, to OHLE as it's the most powerful supply, that Chiltern will have to make more Birmingham trains call at more stops because the better performance of electric trains risks revenue abstraction from Euston-New Street? Currently the fastest Chiltern service is 1h40m which is only about 20 minutes faster than Virgin, and electric could cancel almost all if not all of that difference out. Of course in future things like HS2 and the Williams' review will likely change the London-Birmingham picture.

 

[swt_passenger]

Is it possible that if the Chiltern Mainline achieved full electrification between Marylebone and Birmingham, to OHLE as it's the most powerful supply, that Chiltern will have to make more Birmingham trains call at more stops because the better performance of electric trains risks revenue abstraction from Euston-New Street? Currently the fastest Chiltern service is 1h40m which is only about 20 minutes faster than Virgin, and electric could cancel almost all if not all of that difference out. Of course in future things like HS2 and the Williams' review will likely change the London-Birmingham picture.

I don’t think speeding up Chiltern would be covered by revenue abstraction rules in order to protect the WCML operator. I think nowadays Virgin and their successors would just have to “suck it up”, especially when it’s a franchised operator operating on their own route.
(I think you probably meant to write “...20 minutes slower than Virgin” above by the way?)

 

[Bald Rick]

Is it possible that if the Chiltern Mainline achieved full electrification between Marylebone and Birmingham, to OHLE as it's the most powerful supply, that Chiltern will have to make more Birmingham trains call at more stops because the better performance of electric trains risks revenue abstraction from Euston-New Street? Currently the fastest Chiltern service is 1h40m which is only about 20 minutes faster than Virgin, and electric could cancel almost all if not all of that difference out. Of course in future things like HS2 and the Williams' review will likely change the London-Birmingham picture.

Definitely not. Otherwise Chiltern would have been prevented from knocking the best part of half an hour off their schedules a few years ago!

 

[brad465]

I don’t think speeding up Chiltern would be covered by revenue abstraction rules in order to protect the WCML operator. I think nowadays Virgin and their successors would just have to “suck it up”, especially when it’s a franchised operator operating on their own route.
(I think you probably meant to write “...20 minutes slower than Virgin” above by the way?)

Definitely not. Otherwise Chiltern would have been prevented from knocking the best part of half an hour off their schedules a few years ago!

Sounds fair; I do prefer Chiltern to Virgin when going to Birmingham if possible, given it's a quieter and more scenic route as well as cheaper, while only being slightly slower.