Potential Bi-modes for Marylebone - Aylesbury

[SeanG]

Following the commitment to decarbonisation in the new Chiltern contract (see thread here - https://www.railforums.co.uk/threads/arriva-chiltern-sign-6-year-national-rail-contract.225580/), there was some talk in that thread of battery technology being used.

Could one potential idea be to acquire some 3rd rail & battery bimodes to operate the services over the Met to Aylesbury. I understand that it is approximately 15 miles from Amersham to Aylesbury, so I do not know whether technology would permit a c.30 miles round trip at the northern end. I would imagine that technology would allow for the gap between Marylebone and where the line joins the Met.

Would be interesting to know thoughts.

 

[A0]

Following the commitment to decarbonisation in the new Chiltern contract (see thread here - https://www.railforums.co.uk/threads/arriva-chiltern-sign-6-year-national-rail-contract.225580/), there was some talk in that thread of battery technology being used.

Could one potential idea be to acquire some 3rd rail & battery bimodes to operate the services over the Met to Aylesbury. I understand that it is approximately 15 miles from Amersham to Aylesbury, so I do not know whether technology would permit a c.30 miles round trip at the northern end. I would imagine that technology would allow for the gap between Marylebone and where the line joins the Met.

Would be interesting to know thoughts.

The first question is whether the LUL infrastructure will be able to cope with more trains drawing on the DC infrastructure.

It's also not only Amersham - Aylesbury that needs to be considered but also Marylebone to Harrow on the Hill - which isn't electrified either.

Sorting those out determines the rolling stock. Trying to guess the rolling stock is trying to put the cart before the horse.

 

[Ken H]

The first question is whether the LUL infrastructure will be able to cope with more trains drawing on the DC infrastructure.

It's also not only Amersham - Aylesbury that needs to be considered but also Marylebone to Harrow on the Hill - which isn't electrified either.

Sorting those out determines the rolling stock. Trying to guess the rolling stock is trying to put the cart before the horse.

you could always stick 25kv lines on the unelectrified bits. then you dont have to drag heavy batteries around. Are there still issues with 25kv near LUL lines?

 

[PTR 444]

Surely the most logical thing to do would be to wire Marylebone - Aylesbury via both routes excluding the LUL 4th rail section. I say this because a standard dual voltage fleet can then be ordered to operate all the Chiltern locals while bi-modes are used on services to Oxford and Birmingham.

 

[JonathanH]

Isn't it just more likely that the 165s and 168s will be fitted with batteries? I don't think anyone should get carried away about new stock. Perhaps some 230s are in the offing?

 

[A0]

Isn't it just more likely that the 165s and 168s will be fitted with batteries? I don't think anyone should get carried away about new stock. Perhaps some 230s are in the offing?

Unlikely. They're 20-30 year old units nearing the end of their life.

Add in 2 car 165s aren't great for capacity on busy commuter routes.

I'd expect something new in 3,4 or 5 car configuration depending on carriage length.

 

[popeter45]

i dont think they would run new third rail to Marylebone so that deffo would be 25kv overhead so Aventra units maybe with 3rd rail pickups as dual electrification units if Harrow-Amersham wouldnt be dual electrified?
if overhead was used the entire way would give room for when the S8 are finally replaced to design to run on overhead north of harrow if thats even possible?

 

[CyrusWuff]

The first question is whether the LUL infrastructure will be able to cope with more trains drawing on the DC infrastructure.

Most of the Met has recently had its power supply uprated to 750V nominal (up to 890V with regenerative braking IIRC) for improved performance of the S Stock. It is to be hoped that the maximum possible current draw was increased as part of that.

 

[Bletchleyite]

If the things could be made reliable, this would be a very good case indeed for fourth rail and battery 230s in suitably long walk-through formations. Those would last long enough for proper Chiltern wiring to get on the agenda.

 

[Ken H]

If the things could be made reliable, this would be a very good case indeed for fourth rail and battery 230s in suitably long walk-through formations. Those would last long enough for proper Chiltern wiring to get on the agenda.

Big 'if' ...

 

[A0]

If the things could be made reliable, this would be a very good case indeed for fourth rail and battery 230s in suitably long walk-through formations. Those would last long enough for proper Chiltern wiring to get on the agenda.

Why 230s? They're limited in terms of top speed, there weren't many D78s left. They were designed for certain uses - new builds for Chiltern would make more sense.

 

[RailWonderer]

I don't understand the ambition for class 230s, a shed built repurposed 1970s underground train is not an alternative to a robust mainline DMU for passenger comfort and would be innapropriate for the length of the journeys on Chiltern nor do they have the top speed and acceleration required. Leave 165s and 168s for the 10-15 years they have left then replace them with EMUs and bi-modes and wire up the line in a decade's time. Doing anything sooner makes little sense, it's about a gradual transition done affordably without spending short term only to pander to one group or another.

More broadly I truly do not understand this shock therapy mentality towards electrification and de-carbonisation. Synthetic fuels are a better alternative (Germany is investing in them) and we won't have the national grid power (not affordably anyway) for all this new electric powered rail infrastructure in addition to cars and such.

 

[Bletchleyite]

I don't understand the ambition for class 230s, a shed built repurposed 1970s underground train is not an alternative to a robust mainline DMU for passenger comfort and would be innapropriate for the length of the journeys on Chiltern nor do they have the top speed and acceleration required.

I would agree regarding the Chiltern mainline. But I am talking about Aylesbury, which is little more than an extension of the Metropolitan Line - a suburban service that requires capacity rather than high comfort.

Why 230s? They're limited in terms of top speed, there weren't many D78s left. They were designed for certain uses - new builds for Chiltern would make more sense.

What is the speed limit on the Aylesbury line?

New build DMUs are a bad plan. We need to decide what we are doing regarding electrification, and then order accordingly. My view is that electrifying from both ends is a priority, which would mean going to Wycombe and Banbury first, meaning bi modes for the mainline services and EMUs (350/2s?) for Wycombe locals. But the Aylesbury branch is an oddity. Long term you probably want to wire to Amersham and on the bit connecting Marylebone to the Met and use units with fourth rail and pantographs. But in the meantime you could lose the DMUs on that route with a battery 230 solution which would last the sort of time horizon that it would take to get there.

The Marston Vale was a not dissimilar case. The 230s were designed for about 10-15 years of use, after which EWR will have consolidated/improved the stations and the route will be operated as part of the Cambridge service.

 

[RailWonderer]

I would agree regarding the Chiltern mainline. But I am talking about Aylesbury, which is little more than an extension of the Metropolitan Line - a suburban service that requires capacity rather than high comfort.



What is the speed limit on the Aylesbury line?

To be fair it is 75mph on most sections but the units I presume would be used interchangably with main line units so having a 100mph top speed for all new stock when it is ordered in future makes more sense rather than Aylesbury captive units. That said, when 165s are used on the main line they use slower timings so it is possible Chiltern could keep to that system.

 

[Bletchleyite]

To be fair it is 75mph on most sections but the units I presume would be used interchangably with main line units so having a 100mph top speed for all new stock when it is ordered in future makes more sense rather than Aylesbury captive units. That said, when 165s are used on the main line they use slower timings so it is possible Chiltern could keep to that system.

Are even the shared parts 75 mph linespeed, given that S stock is rather slower than that?

Captive units make more sense, the line is totally different to the Chiltern mainline, being an extended suburban local service. It is more like the situation on Merseyrail* but without the buffer stops at Amersham. In some ways it would make most sense to electrify the Met out to Aylesbury and stop Chiltern operating it entirely.

* That is, the electric service operating up to the end of the more built up bit, then a diesel bit that runs through more rural country to a significant town at the end. Very similar to the Ormskirk and Kirkby lines, but longer and with higher demand.

 

[RailWonderer]

Are even the shared parts 75 mph linespeed, given that S stock is rather slower than that?

THe Met reaches 60mph at most so I would agree the Aylesbury line is really a glorified metro route.

 

[GRALISTAIR]

I would be gobsmacked if the business case for Chilterns electrification did not stack up. It ticks a lot of boxes surely. Trimodes that can be modified to bimodes the full electric later?

 

[A0]

I would agree regarding the Chiltern mainline. But I am talking about Aylesbury, which is little more than an extension of the Metropolitan Line - a suburban service that requires capacity rather than high comfort.

But the fleet currently is interchangeable, so 165s can be used on Wycombe line services.

Having an "Aylesbury via Amersham" only solution means that flexibility would be lost unnecessarily.

 

[anthony263]

Could a class 755 be built which can draw power from 3rd rail rather than AC

 

[A0]

THe Met reaches 60mph at most so I would agree the Aylesbury line is really a glorified metro route.

The Aylesbury line runs non-stop to Harrow on the Hill, then non stop to Rickmansworth, then stopping at Chorleywood, Chalfont & Latimer and Amersham. Whereas the Met from Baker Street to Amersham stops 4 times between Baker St and Harrow and 8 times between Harrow and Amersham.

The Aylesbury line is more like the "outer suburban" services on the GN with the Met more like the "inner suburbans".

 

[JonathanH]

I would be gobsmacked if the business case for Chilterns electrification did not stack up. It ticks a lot of boxes surely. Trimodes that can be modified to bimodes the full electric later?

No business case for electrification stacks up without the government providing the finance. If it did, then private investment would have already funded it.

The obvious problem with Chiltern electrification is that there are no intensive short distance services which represent a quick win with much of the service running on lines which are only 1tph or 2tph for much of the day.

 

[Bletchleyite]

But the fleet currently is interchangeable, so 165s can be used on Wycombe line services.

Having an "Aylesbury via Amersham" only solution means that flexibility would be lost unnecessarily.

I wouldn't say unnecessarily. The two routes are totally different, and so dedicated stock makes more sense.

There are basically 3 service groups in terms of stock needs once electrification starts:
Birmingham/Oxford: longer distance, 2+2 with tables etc, likely to need bi mode for the foreseeable
Wycombe locals: 3+2 seated EMU like 350s, or even better with large standbacks and wide doors like Northern's CAF kit
Aylesbury: something like Wycombe but with fourth rail kit

 

[A0]

I wouldn't say unnecessarily. The two routes are totally different, and so dedicated stock makes more sense.


Wycombe locals: 3+2 seated EMU like 350s, or even better with large standbacks and wide doors like Northern's CAF kit
Aylesbury: something like Wycombe but with fourth rail kit

You seem to be contradicting yourself, since the only difference between the bottom two is the need for 3rd / 4th rail pick up - which begs the obvious question why split them? *Much* easier to have a common fleet.

 

[Bletchleyite]

You seem to be contradicting yourself, since the only difference between the bottom two is the need for 3rd / 4th rail pick up - which begs the obvious question why split them? *Much* easier to have a common fleet.

With electrification, yes, two fleets (local and regional). But until then (10-15 years perhaps) what you need for the Aylesburys is fourth rail and battery. And guess who can do that quite easily?

 

[A0]

With electrification, yes, two fleets (local and regional). But until then (10-15 years perhaps) what you need for the Aylesburys is fourth rail and battery. And guess who can do that quite easily?

Better off waiting until the new stock is ordered. The 165s will last until then - adding a stop gap, unless it offered a capacity improvement - is a waste of time & effort.

 

[tomuk]

Crayon Time

Metropolitan line to serve Watford Junction only (via Croxley Link)
Aylesbury and Chesham to be served by Crossrail services via Dudding Hill from OOC to Neasden then Metropolitan fast lines.

 

[The Ham]

I don't understand the ambition for class 230s, a shed built repurposed 1970s underground train is not an alternative to a robust mainline DMU for passenger comfort and would be innapropriate for the length of the journeys on Chiltern nor do they have the top speed and acceleration required. Leave 165s and 168s for the 10-15 years they have left then replace them with EMUs and bi-modes and wire up the line in a decade's time. Doing anything sooner makes little sense, it's about a gradual transition done affordably without spending short term only to pander to one group or another.

More broadly I truly do not understand this shock therapy mentality towards electrification and de-carbonisation. Synthetic fuels are a better alternative (Germany is investing in them) and we won't have the national grid power (not affordably anyway) for all this new electric powered rail infrastructure in addition to cars and such.

What probably needs to happen (as we can't just string to the wires over one evening) is for a series of small steps to get us to a point where we have the wires up in 10 years time.

If we are looking for decarbonisation as a priority adding batteries to the trains (charged from breaking) to reduce diesel fuel use by circa 20% would be a good first step.

Whilst that's being delivered stay planning what to do with delivering the wires and how that can further reduce emissions (wiring outwards from Birmingham could be a good start).

Then actually start to deliver those wiring schemes so that there's enough up to replace the DMU's in 10 years time.

There's the potential for that not to need 100% wire everything, as it could be EMU's with batteries to bridge the remaining gaps.

 

[SynthD]

Britain's very first 100mph battery-diesel hybrid train leaves Marylebone station in London today - City AM

Britain’s very first 100mph battery-diesel hybrid train is entering passenger service to cut carbon emissions and boost air quality. Chiltern Railways will introduce the train on its 40-mile route between London Marylebone and Aylesbury, Buckinghamshire, today. There are plans to use it between...

www.cityam.com

Britain’s very first 100mph battery-diesel hybrid train is entering passenger service to cut carbon emissions and boost air quality.

Chiltern Railways will introduce the train on its 40-mile route between London Marylebone and Aylesbury, Buckinghamshire, today.

There are plans to use it between the capital and Oxford in the coming months.

https://twitter.com/chilternrailway/status/1493135642770948097

Their twitter says it's not in passenger service yet.

 

[Railwaysceptic]

Britain's very first 100mph battery-diesel hybrid train leaves Marylebone station in London today - City AM

Britain’s very first 100mph battery-diesel hybrid train is entering passenger service to cut carbon emissions and boost air quality. Chiltern Railways will introduce the train on its 40-mile route between London Marylebone and Aylesbury, Buckinghamshire, today. There are plans to use it between...

www.cityam.com

https://twitter.com/chilternrailway/status/1493135642770948097

Their twitter says it's not in passenger service yet.

Interesting but with little detail. Will the batteries be re-charged when running over the third rail sections or will the diesel engine do it?

As overhead electrification in St. Johns Wood and Hampstead tunnels would be challenging, this hybrid holds great promise.

 

[Mikey C]

Interesting but with little detail. Will the batteries be re-charged when running over the third rail sections or will the diesel engine do it?

As overhead electrification in St. Johns Wood and Hampstead tunnels would be challenging, this hybrid holds great promise.

I assume this is like a self charging hybrid car or bus, where the engines and braking power the battery. I imagine the main benefit will be for air quality at stations, where the train can arrive and depart using battery power