I thought this was interesting: https://www.bbc.co.uk/news/articles/c2l7ry7zp5po

The run was a bit artificial, in that they ran the train at ~40mph rather than its top speed of 60mph, but I think it has to be seen as a proof-of-concept demonstration for the public (and doubtless for the politicians who may need to come up with funds to build battery trains and install charging equipment.) The idea is for GWR eventually to replace its ageing diesel multiple units, used for local start-stop services on non-electrified branch lines, with battery trains.

This train is very familiar to Londoners like me, as it is converted from a withdrawn District Line Underground train. It normally runs, as a battery train, on a trial commercial GWR shuttle service, which has now been in operation for a year. There are contacts between the running rails at each terminus, which allow fast charging while the train is waiting between scheduled journeys. The shuttle route is only about 3 miles long, on a branch line between West Ealing and Greenford. However the aim has been to test the robustness of the charging system and batteries over many cycles, in all weathers, rather than run long distances which would give comparatively little useful information about the critical components of the concept.

The 200 mile route was Reading-London Paddington, then Paddington-Oxford and back, then return to Reading. The first time an Underground train has been to Oxford! The previous record was 130 miles, in Germany.

I suspect to implement this at scale they may want a train able to reach 70-80mph, with a range between charging termini of 50-80 miles or so. It looks to me as if the batteries on this train could just about do that, in a train with more powerful motors.

Edited August 21Aug 21 by exchemist

They don’t mention what load was being hauled, and how that would affect the range.

Sounds like operating those trains has already been happening (since 2018?). A battery-electric version of a diesel-electric rather than full electric (pantograph or electrified rails) converted to batteries - which is being done elsewhere (in Europe iirc) - was being done even before climate and emissions concerns, simply as the cheaper alternative to electrifying tracks between electrified sections. Better batteries, faster charging seem possible now.

I think such solutions will work well for railways. For freight I expect swapping dedicated battery cars (or swapping container - without the shunting) would be an alternative to recharging on-board batteries. Rail corridors could also host a lot of solar - although transmission means local isn't necessary a great advantage.

Edited August 22Aug 22 by Ken Fabian

If any is interested; similar subject: fly 130Km for $8 on electric aircraft ----> https://www.youtube.com/watch?v=DJaDN1eeeDE

6 hours ago, swansont said:

They don’t mention what load was being hauled, and how that would affect the range.

Being an Underground train it’s an Electric Multiple Unit carrying passengers, rather than a locomotive hauling a load. But indeed, they don’t say how many people and what weight of monitoring equipment was on board , compared to a full complement of passengers. The branch lines in the Thames Valley are fairly flat, I think, so I don’t think there would be many steep gradients. But in real service I’ve no doubt the inefficiencies of stop start operation would bring the effective range down quite a lot.

There’s a YouTube video of the run which I watched. I was interested that they depleted the six battery packs sequentially rather than all together. I don’t know why that would be an advantage. They finished with one pack almost unused.

1 hour ago, exchemist said:

There’s a YouTube video of the run which I watched. I was interested that they depleted the six battery packs sequentially rather than all together. I don’t know why that would be an advantage. They finished with one pack almost unused.

My guess is it might be some way of mitigating long term degradation and part of a maintenance/longevity strategy. Excessive internal heat shortens Li-ion battery life, as an example, so, perhaps sequential use helps overall cooling.

Edited August 22Aug 22 by StringJunky

7 hours ago, exchemist said:

I was interested that they depleted the six battery packs sequentially rather than all together. I don’t know why that would be an advantage.

My guess would be swapping rather than waiting to recharge, leading to quicker turnaround, for when this goes into service.

7 hours ago, StringJunky said:

My guess is it might be some way of mitigating long term degradation and part of a maintenance/longevity strategy. Excessive internal heat shortens Li-ion battery life, as an example, so, perhaps sequential use helps overall cooling.

Slow recharging would help with that, too. Full discharge of the battery might be a factor; IIRC NiCd batteries preferred that.

2 hours ago, swansont said:

My guess would be swapping rather than waiting to recharge, leading to quicker turnaround, for when this goes into service.

The operating principle is fast recharging at termini, from connectors on the track. Not battery swapping, which would be far too slow and laborious, and probably could not be done alongside a busy railway platform. No, it must be something to do with the discharge characteristics of the battery system, I think. Could be the heat issue mentioned by @StringJunky .

21 hours ago, exchemist said:

The 200 mile route was Reading-London Paddington, then Paddington-Oxford and back, then return to Reading. The first time an Underground train has been to Oxford! The previous record was 130 miles, in Germany.

You may be curious to learn that ex-London Underground electric rolling-stock has been in use on the Isle of Wight Railway line from Ryde to Shanklin since 1967.

https://en.wikipedia.org/wiki/Isle_of_Wight_Railway

This line first opened in stages; between Ryde and Shanklin in 1864, followed by an extension to Ventnor in 1866, a total length of around 12 miles. From the outset the company used steam traction, employing a fleet of Beyer Peacock 0-4-4T type tank engines which were said to be the only steam locomotives capable of working the very low Ryde tunnel in particular.

In 1966 the Ventor extension was closed, and the line was truncated  and electrified, now ending in Shanklin. Because of the low tunnel height clearance in Ryde, engineers found that the only available  locomotives capable of operating on the newly electrified line were vintage 1925 era London Underground units. Around 43 of these were acquired from the Piccadilly and Northern Lines, shipped to the Island and modified to run on a 630VDC third rail system, using a running rail as the current return circuit.

These 1925 era tube trains remained in service on the IOWRL until 1989, when they were upgraded  - (if that is the word) - to 1938 vintage London Underground class 483 EMUs (electric multiple units).

In a final major upgrade that took place in 2021, the vintage 1938 London Underground stock was replaced with newer Class 484 ex-London Underground carriages - this time from the 1980s.

https://www.theguardian.com/uk-news/2020/jan/02/isle-of-wights-rattling-rolling-charming-ex-tube-trains-face-end-of-the-line

11 minutes ago, toucana said:

You may be curious to learn that ex-London Underground electric rolling-stock has been in use on the Isle of Wight Railway line from Ryde to Shanklin since 1967.

https://en.wikipedia.org/wiki/Isle_of_Wight_Railway

This line first opened in stages; between Ryde and Shanklin in 1864, followed by an extension to Ventnor in 1866, a total length of around 12 miles. From the outset the company used steam traction, employing a fleet of Beyer Peacock 0-4-4T type tank engines which were said to be the only steam locomotives capable of working the very low Ryde tunnel in particular.

In 1966 the Ventor extension was closed, and the line was truncated  and electrified, now ending in Shanklin. Because of the low tunnel height clearance in Ryde, engineers found that the only available  locomotives capable of operating on the newly electrified line were vintage 1925 era London Underground units. Around 43 of these were acquired from the Piccadilly and Northern Lines, shipped to the Island and modified to run on a 630VDC third rail system, using a running rail as the current return circuit.

These 1925 era tube trains remained in service on the IOWRL until 1989, when they were upgraded  - (if that is the word) - to 1938 vintage London Underground class 483 EMUs (electric multiple units).

In a final major upgrade that took place in 2021, the vintage 1938 London Underground stock was replaced with newer Class 484 ex-London Underground carriages - this time from the 1980s.

https://www.theguardian.com/uk-news/2020/jan/02/isle-of-wights-rattling-rolling-charming-ex-tube-trains-face-end-of-the-line

I know. But for some reason those always seem to have been Tube stock. This one is ex District Line, so built to the full BR loading gauge rather than having to fit into a 12ft diameter tube:

The pic shows A stock which served on the Metropolitan Line, but the dimensions are almost the same.

I can't think why the Isle of Wight chooses Tube stock. They're not all dwarves, are they?

1 hour ago, exchemist said:

can't think why the Isle of Wight chooses Tube stock. They're not all dwarves, are they?

1 hour ago, toucana said:

In 1966 the Ventor extension was closed, and the line was truncated  and electrified, now ending in Shanklin. Because of the low tunnel height clearance in Ryde, engineers found that the only available  locomotives capable of operating on the newly electrified line were vintage 1925 era London Underground units. Around 43 of these were acquired from the Piccadilly and Northern Lines, shipped to the Island

On the battery use I wondered if their batteries don't deep cycle too well, so it's seen as better to run each down to say, 20%, then switch over to the next one. If they all drained at once there might be temptation to dip into the bottom 20% whereas sequential use means you're low when five of six are done but you've got that reserve battery if you're a little before the next recharge stop. Just guessing here.

ETA - and if the batteries DO deep cycle well and are prone to memory effect (some batteries when not drained to their maximum on a regular basis, will "remember" that incomplete discharge level and suffer reduced storage), then the sequential system is also an advantage. All but the reserve battery gets fully cycled, as opposed to simultaneous draining where you might have routes where all the batteries only go down to, say, 35% and you get the pesky memory effect.

Edited August 22Aug 22 by TheVat
ETA

2 hours ago, exchemist said:

I can't think why the Isle of Wight chooses Tube stock. They're not all dwarves, are they?

When the IoWR opened their Ryde to Shanklin railway line in 1864, they were forced to build their main terminus at St Johns Road on the south side of the town, at an inconvenient distance from the Pier and Ryde Esplanade where all the summer visitors arrived on the pleasure steamers.  IoWR had to rely on a horse-drawn tram link to get these passengers to the railway station. It took another 16 years of argument to obtain permission to build a rail tunnel to connect St Johns Road to Ryde Pier and Esplanade.

As the wiki article explains:

The difficulty of passing the new line under the Esplanade, considered an important beauty spot in Ryde, led to the line being built with a low headroom (at 12 ft 3in); this was to limit the introduction of some traction designs in later years. IoWR trains began working to Ryde Esplanade station on 5 April 1880 and to Ryde Pier Head on 12 July 1880”

https://en.wikipedia.org/wiki/Isle_of_Wight_Railway

11 hours ago, TheVat said:

On the battery use I wondered if their batteries don't deep cycle too well, so it's seen as better to run each down to say, 20%, then switch over to the next one. If they all drained at once there might be temptation to dip into the bottom 20% whereas sequential use means you're low when five of six are done but you've got that reserve battery if you're a little before the next recharge stop. Just guessing here.

ETA - and if the batteries DO deep cycle well and are prone to memory effect (some batteries when not drained to their maximum on a regular basis, will "remember" that incomplete discharge level and suffer reduced storage), then the sequential system is also an advantage. All but the reserve battery gets fully cycled, as opposed to simultaneous draining where you might have routes where all the batteries only go down to, say, 35% and you get the pesky memory effect.

That sounds like a quite likely explanation.

10 hours ago, toucana said:

When the IoWR opened their Ryde to Shanklin railway line in 1864, they were forced to build their main terminus at St Johns Road on the south side of the town, at an inconvenient distance from the Pier and Ryde Esplanade where all the summer visitors arrived on the pleasure steamers.  IoWR had to rely on a horse-drawn tram link to get these passengers to the railway station. It took another 16 years of argument to obtain permission to build a rail tunnel to connect St Johns Road to Ryde Pier and Esplanade.

As the wiki article explains:

Ah so that's it. Quite nice in a way that old Tube stock gets a new lease of life on the Isle of Wight. I've never been there, though I visit Portsmouth regularly to catch the overnight ferry to St Malo. I should go one day. They have a lot of fossils, I understand. Apart from ancient Underground trains, I mean......

1 hour ago, exchemist said:

That sounds like a quite likely explanation.

Ah so that's it. Quite nice in a way that old Tube stock gets a new lease of life on the Isle of Wight. I've never been there, though I visit Portsmouth regularly to catch the overnight ferry to St Malo. I should go one day. They have a lot of fossils, I understand. Apart from ancient Underground trains, I mean......

This problem was made even worse when engineers found they needed to raise the existing floor level of the Ryde tunnel to prevent flooding

Although very small (just 55 miles of track in total), the Isle of Wight railway system in its prime was built by five different companies, and is chock-full of absurdities and eccentricities that offer a perfect microcosm of the challenges faced by Victorian railway engineers.

The Shanklin-Ventnor extension on the IoWR line for example was held up for two years until 1866 because the landowner who was the Earl of Yarborough refused to allow a line to be built over his property. The company was forced go via Wroxall instead, and drive a vastly expensive 1,312 yard tunnel under St Boniface Down. Ventnor station itself then had to be built in a disused chalk pit on a ledge quarried into the hillside just beyond the tunnel mouth, some 294 feet above sea-level. A turntable was installed to reverse the locomotives.

The IoWR persevered with this expense because Ventnor with its unique micro-climate was a popular location for sanitoriums catering for patients with pulmonary tuberculosis. Once the Ryde Esplanade tunnel was finished in 1880, the IoWR used to run a regular summer ‘Invalid Express’ service which enabled convalescents to step off a ferry steamer at Ryde Pier, and straight onto a train that whisked them down to Ventnor in 30m.

When the IoWR decided to build a branch line from Sandown to Newport, they had to construct a substantial railway viaduct over the river Medina. Members of my mother’s family owned a critical plot of land needed for this viaduct, and made a handsome sum by selling it to the railway company who went bankrupt as a result. When the Medina viaduct was finished, it had to include a sliding section that could be opened to allow tall masted sailing ships to navigate down the river - which caused endless problems.

Whippingham station on this line was built for the private use of Queen Victoria when residing at Osborne House. But Queen Victoria hated travelling by rail, and she returned the station to public use. As the only other facility in the area was a crematorium, the station remained largely unused.

The final part of the Island network, the Newport-Freshwater branch line constructed in 1897 includes Watchingwell station which was buillt as a private facility for  the landowner John Barrington Simeon MP for Southampton who refused to allow the railway line onto his land unless the company provided him with his own private station - complete with a semaphore signal to request trains to stop. This halt was only added into the public timetables in 1923 after Southern Rail took control.

Edited August 23Aug 23 by toucana
typo - "micro"