Chiltern considers Turbo future

[tomuk]

You could change at Harrow On the Hill or Wembley Park or Finchley Road if the Jubilee was desired.

 

[bramling]

While the most worrying concern mixing HV AC overhead with DC power on the same tracks is avoided with a four rail DC system, namely the stray current problem, there would still be a large amount of work, including structural clearance but also signalling and pretty much everything electrical in the vicinity of the new wires would need to be assessed and possibly modified or renewed. The new LUL SelTrac signallling on the SSL might well be inherently immune as it doesn't use conventional track circuits, but I'm not sure of the likely extent of this in the future in the context of possible electrification timescales. Any areas retaining track circuits would need extensive impedance bond provision to segregate traction return current from (double rail?) track circuits, which I think are audio frequency types on the Met now. Of course, the major dual electrification project mooted in this thread might be instrumental in getting the new signalling completed throughout the affected areas.

The dates have changed so many times I couldn’t say off-hand, however the Amersham section of the Met isn’t that far off resignalling now. Certainly it should get there quicker than an electrification scheme could be designed, especially a rather non-standard one.

The eastern tip of the District Line next on the list, then it’s the turn of the Met working outwards in stages.

My personal hunch is that the amount of design and contractual work associated with doing anything on the Met section risks the whole thing ending up in the “too awkward” box, especially as there’s little direct benefit for TfL, and apart from reducing diesel fumes not much for London either. I can’t really see much enthusiasm from TfL, though of course if someone else is paying then anything is possible.

 

[CyrusWuff]

There are already a number of ex-Thames Trains 165s and 166s in the west, and working out of Bristol on the Cardiff-Portsmouth axis for GWR and more will likely come if electrification to Oxford and Basingstoke is ever completed and a new solution found for the Thames Valley branches. I believe there are some detail differences between ex-Thames units and those on Chiltern, but they must be very similar.

Differences between the Chiltern (165/0) and GWR (165/1) fleets include:

• 165/0s are (currently) fitted with ATP equipment, whereas the /1s aren't.
• /1s are geared for 90mph running, whereas /0s top out at 75mph.
• /1s retain their original hopper windows, whereas /0s had theirs removed at refurbishment as part of the installation of air conditioning.
• /1s have (regained) First Class seating, where the /0s had it removed at refurbishment.

There are almost certainly other differences, but those are the most obvious ones.

 

[MarkyT]

The dates have changed so many times I couldn’t say off-hand, however the Amersham section of the Met isn’t that far off resignalling now. Certainly it should get there quicker than an electrification scheme could be designed, especially a rather non-standard one.

The eastern tip of the District Line next on the list, then it’s the turn of the Met working outwards in stages.

My personal hunch is that the amount of design and contractual work associated with doing anything on the Met section risks the whole thing ending up in the “too awkward” box, especially as there’s little direct benefit for TfL, and apart from reducing diesel fumes not much for London either. I can’t really see much enthusiasm from TfL, though of course if someone else is paying then anything is possible.

Certainly from TfL's perspective, by far the easiest solution would be for new Chiltern trains (or at least a subfleet proportion that works over the Aylesbury line) to have 4-rail power capability built in from new, organising any small supply reinforcements needed. New trains with ETCS could also potentially emulate SelTrac signalling to some extent without there being additional mechanical trainstops needed as previously planned for compatibility with the old trains. The emulation might nontheless limit Chiltern services to fixed block operation for simplicity within TfL territory, but the signalling might not need the extra antiquated transponders etc, as the trains might utilise their standard ETCS balise readers and radio systems for positioning and movement authority. It would certainly be somewhat anachronistic for brand new ETCS capable trains to have to be fitted with 19th century mechanical tripcocks for operation over infrastructure itself equipped with another modern CBTC solution!

 

[Mikey C]

Differences between the Chiltern (165/0) and GWR (165/1) fleets include:

• 165/0s are (currently) fitted with ATP equipment, whereas the /1s aren't.
• /1s are geared for 90mph running, whereas /0s top out at 75mph.
• /1s retain their original hopper windows, whereas /0s had theirs removed at refurbishment as part of the installation of air conditioning.
• /1s have (regained) First Class seating, where the /0s had it removed at refurbishment.

There are almost certainly other differences, but those are the most obvious ones.

The 165/0s have 2+2 seating at the ends of each train, which is pretty comparable to 1st class seating anyway

 

[anthony263]

Certainly from TfL's perspective, by far the easiest solution would be for new Chiltern trains (or at least a subfleet proportion that works over the Aylesbury line) to have 4-rail power capability built in from new, organising any small supply reinforcements needed. New trains with ETCS could also potentially emulate SelTrac signalling to some extent without there being additional mechanical trainstops needed as previously planned for compatibility with the old trains. The emulation might nontheless limit Chiltern services to fixed block operation for simplicity within TfL territory, but the signalling might not need the extra antiquated transponders etc, as the trains might utilise their standard ETCS balise readers and radio systems for positioning and movement authority. It would certainly be somewhat anachronistic for brand new ETCS capable trains to have to be fitted with 19th century mechanical tripcocks for operation over infrastructure itself equipped with another modern CBTC solution!

A class 756 with diesel and batteries plus capability to run.off 3rd or 4th rail would be ideal

 

[Mark J]

I've never understood why Chiltern have the 75mph variants, yet GWR use the 90mph variants on the Henley, Marlow, Windsor and Greenford branch lines.

Surely there should have been a swap around to let Chiltern have those 90mph units and GWR had the 75mph units for the branch lines.

 

[Energy]

I've never understood why Chiltern have the 75mph variants, yet GWR use the 90mph variants on the Henley, Marlow, Windsor and Greenford branch lines.

Surely there should have been a swap around to let Chiltern have those 90mph units and GWR had the 75mph units for the branch lines.

The 90mph mods require a yaw dampener to be installed, Chiltern already use that spot for the trip cocks for the LU section.

 

[JonathanH]

I've never understood why Chiltern have the 75mph variants, yet GWR use the 90mph variants on the Henley, Marlow, Windsor and Greenford branch lines.

Surely there should have been a swap around to let Chiltern have those 90mph units and GWR had the 75mph units for the branch lines.

Thames Trains did have seven of the 75mph units for a while, gradually reduced to five, then three before they went back to Chiltern in the early 2000s. As another poster pointed out, a subfleet of 90mph units without Tripcocks on Chiltern wouldn't be helpful.

 

[Recessio]

Will tripcocks still be necessary once the Met resignalling is done? I'm not up to date on the specifics of how NR interfaces with the LU signaling.

 

[MarkyT]

Will tripcocks still be necessary once the Met resignalling is done? I'm not up to date on the specifics of how NR interfaces with the LU signaling.

That was the intention originally. On the particular sections shared with Chiltern, the new LU signalling was to be overlaid with new fixed block conventional signals and mechanical trainstops, to maintain compatibility with the existing Chiltern fleet, equipped with tripcocks, AWS/TPWS, and the now obsolete Selcab ATP system (installed from new as part of the BR train protection pilot scheme). New trains for this line might be able to use the new LU SelTrac directly if specified accordingly, or be compatible with a fixed block overlay implemented using modern ETCS equipment instead of a 19th-century system!

 

[Recessio]

That was the intention originally. On the particular sections shared with Chiltern, the new LU signalling was to be overlaid with new fixed block conventional signals and mechanical trainstops, to maintain compatibility with the existing Chiltern fleet, equipped with tripcocks, AWS/TPWS, and the now obsolete Selcab ATP system (installed from new as part of the BR train protection pilot scheme). New trains for this line might be able to use the new LU SelTrac directly if specified accordingly, or be compatible with a fixed block overlay implemented using modern ETCS equipment instead of a 19th-century system!

Thank you. But wouldn't having to keep fixed block signals (with or without tripcocks) defeat the point of having a moving-block system to increase tph? (sorry I forget the correct terminology for the new system)

 

[Domh245]

Thank you. But wouldn't having to keep fixed block signals (with or without tripcocks) defeat the point of having a moving-block system to increase tph? (sorry I forget the correct terminology for the new system)

It does if you are concerned about capacity. However, capacity isn't a particular concern on the far reaches of the Metropolitan, the new signalling is effectively replacing end of life assets with the new standard system for the Subsurface lines. It also (assuming it's set up how I remember) still allows for higher capacity if you've got 2 Met trains following each other - it's only NR trains that will actually use the block signals

 

[MarkyT]

It does if you are concerned about capacity. However, capacity isn't a particular concern on the far reaches of the Metropolitan, the new signalling is effectively replacing end of life assets with the new standard system for the Subsurface lines. It also (assuming it's set up how I remember) still allows for higher capacity if you've got 2 Met trains following each other - it's only NR trains that will actually use the block signals

Outside peaks at least, I believe Chiltern trains have the fasts north of Harrow largely to themselves anyway. That Seltrac can do moving block is incidental really at the peripheries, it's just the new standard system for S stock on the subsurface network.

 

[Recessio]

It does if you are concerned about capacity. However, capacity isn't a particular concern on the far reaches of the Metropolitan, the new signalling is effectively replacing end of life assets with the new standard system for the Subsurface lines. It also (assuming it's set up how I remember) still allows for higher capacity if you've got 2 Met trains following each other - it's only NR trains that will actually use the block signals

Outside peaks at least, I believe Chiltern trains have the fasts north of Harrow largely to themselves anyway. That Seltrac can do moving block is incidental really at the peripheries, it's just the new standard system for S stock on the subsurface network.

That makes a lot of sense. Thanks both, really appreciate the explanations.

 

[TrainTrackJack]

Reported in this months Railway Magazine:

"Battery-electric units sought by Chiltern"

"Chiltern Railways is seeking expressions of interest from manufacturers with a view to the procurement of 30-70 battery-electric multiple units (BEMUs).
It says it is assessing its strategy with a particular focus on "rolling stock that can achieve non-diesel operation".
Excluding VAT, the estimated value of the contract, which would involve the supply of new trains and associated maintenance, charging infrastructure and depot modifications, is £400 million, although the company is also entertaining proposals for the supply of multiple units converted to battery-electric operation as an alternative."

(note for mods: split thread here into Traction and Rolling Stock subcategory as this has been published?)

 

[43102EMR]

Reported in this months Railway Magazine:

"Battery-electric units sought by Chiltern"

"Chiltern Railways is seeking expressions of interest from manufacturers with a view to the procurement of 30-70 battery-electric multiple units (BEMUs).
It says it is assessing its strategy with a particular focus on "rolling stock that can achieve non-diesel operation".
Excluding VAT, the estimated value of the contract, which would involve the supply of new trains and associated maintenance, charging infrastructure and depot modifications, is £400 million, although the company is also entertaining proposals for the supply of multiple units converted to battery-electric operation as an alternative."

(note for mods: split thread here into Traction and Rolling Stock subcategory as this has been published?)

Will be interesting to see how Chiltern pull this off, especially for their core route between Birmingham and London - can’t foresee electric trains being useful without a full electrification project of the Chiltern Main Line.