UK government's Transport decarbonisation plan

[whole diary]

[johnneyw]

Merseyside's Metro Mayor seems to be interested in battery power to expand Merseyrail according to this article that I stumbled across:

https://www.bbc.co.uk/news/uk-england-merseyside-57853592.amp

[eightonedee]

Full overhead wiring looks like it will only get as far as Exeter, then on battery power to say Newton Abbot -Plymouth to get over the banks and charge the batteries for the trip into Cornwall. The other saving is no overhead in stations low bridges, or level crossings.

I really hope that this is not the case! It is beyond appalling if Plymouth at least does not get OHL^▸ (Over-Head Line) when places as diverse as King's Lynn, Harwich, Clacton, Norwich and Skipton already have it.

 

[REVUpminster]

Full overhead wiring looks like it will only get as far as Exeter, then on battery power to say Newton Abbot -Plymouth to get over the banks and charge the batteries for the trip into Cornwall. The other saving is no overhead in stations low bridges, or level crossings.

I really hope that this is not the case! It is beyond appalling if Plymouth at least does not get OHL^▸ (Over-Head Line) when places as diverse as King's Lynn, Harwich, Clacton, Norwich and Skipton already have it.

 

Would it be such a loss if the wires stopped short of a complex junction or multi-platform station if the batteries had just been fully charged on a simple stretch of overhead wires.  If battery trains are successful the wiring at Paddington maybe could be removed. No maintenace and CHEAP.

[stuving]

GWR^▸ (Great Western Railway) are looking to convert an 802 to battery by taking the diesel generators and fuel tanks out replaced by batteries.

Page 78 has a map https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1002285/decarbonising-transport-a-better-greener-britain.pdf

Full overhead wiring looks like it will only get as far as Exeter, then on battery power to say Newton Abbot -Plymouth to get over the banks and charge the batteries for the trip into Cornwall. The other saving is no overhead in stations low bridges, or level crossings.

I don't think those to points are linked, are they? And both are old news! The battery in an 802 was announced by Hitachi last December , and while grossly oversold in reports is basically an experiment. And it's primarily Hitachi's project, with Eversholt's approval (as ROSCO^» (Rolling Stock Owning Company - about) owning the train), Hyperdrive's collaboration (making the battery packs), and GWR's assistance in running the trains (it's not clear what staff and whose that will call for).

The map is straight out of NR^» (Network Rail - home page)'s Traction Decarbonisation Network Strategy which came out a year ago (why was it called a business case when published?). There was rather less interest shown then in its own thread. Note that those light green "ancillary electrification" lines are identified as requiring electrification, but given lower priority as no suitable method has been defined (yet).

The key point this time, I think, is this government's commitment to electrification "guided by" that NR strategy. Obviously no string has been measured, let alone cut to length, but then a plan with named names and dates was never going to happen yet. 

[Reading General]

Full overhead wiring looks like it will only get as far as Exeter, then on battery power to say Newton Abbot -Plymouth to get over the banks and charge the batteries for the trip into Cornwall. The other saving is no overhead in stations low bridges, or level crossings.

I really hope that this is not the case! It is beyond appalling if Plymouth at least does not get OHL^▸ (Over-Head Line) when places as diverse as King's Lynn, Harwich, Clacton, Norwich and Skipton already have it.

 

Would it be such a loss if the wires stopped short of a complex junction or multi-platform station if the batteries had just been fully charged on a simple stretch of overhead wires.  If battery trains are successful the wiring at Paddington maybe could be removed. No maintenace and CHEAP.

But this is aimed at cost saving again. Maintenance means reliability, a cost that cannot be calculated. Not to mention every train requiring a battery that will need materials continually sourced and questionable disposal. Over head wiring works, it has worked for decades. Planning because the technology might get better in the future is just short term thinking and cost saving. Batteries will have their uses on branch lines and sensitive locations but all mainline railways should be electrified. I feel the same with buses. Yes batteries can be used but we need to reduce the reliance on them where routes are generally fixed in urban areas. If it doesn’t change route except for the occasional incident, wire it. Additionally, are we going to manage charging every car, lorry, bus and train overnight?

[broadgage]

I can see the merits of battery trains for branch line or secondary routes where the limited traffic does not justify electrification.
I can also see the merits of battery power for short sections of existing main lines that are problematic to electrify, Dawlish is the obvious example.
Battery power would also be most useful to proceed, possibly at reduced performance, when the wires come down. And for on board services when the train can not proceed for any reason.

I would not support battery power for long distances on fast or busy main lines as an alternative to electrification.  HMG are trying very hard to look green but without making any significant progress towards electrification of all fast or busy lines.

Subject to the odd SHORT gap, London to Plymouth should be electrified in the near term, and eventually to Penzance.

[TonyK]

Merseyside's Metro Mayor seems to be interested in battery power to expand Merseyrail according to this article that I stumbled across:

https://www.bbc.co.uk/news/uk-england-merseyside-57853592.amp

The batteries for the Class 777 weigh around 5 tonnes. The range is "up to 20 miles" on a single charge, meaning "up to" 10 miles each way, unless they can charge at the distant station. I wonder what the difference in cost is between equipping new trains with batteries, as opposed to extending the third rail for a few miles?

Still, it gives the chance to see how a train full of commuters on a wet winter morning behaves under battery power, and somewhere that won't affect me if it all goes stomach skywards.

[broadgage]

"Up to 20 miles" does not sound very impressive for 5 tons of battery.
Does anyone have more technical details such as battery capacity in kwh and energy used per mile run.

[grahame]

Subject to the odd SHORT gap, London to Plymouth should be electrified in the near term, and eventually to Penzance.

The sea wall and the single track tunnel bores seem obvious examples; perhaps the bridge between St Budeaux and Saltash too if the opportunity of electrification is not taken to double track it  . 

How is acceleration from stops on battery compared to on main catenary power?   I would have thought battery drain was far higher from a start than if maintaining speed, and perhaps stations are not good places to miss out from overheads, Dawlish excepted!

[Reading General]

Complete an inland route and wires can reach Plymouth, then local trains along the sea wall can run on wire where necessary and battery in sensitive areas. A battery locomotive could drag the train from Plymouth to the other side of the tamar.

[stuving]

One of the bundle of documents released with the TDP was the Rail environment policy statement. This covers a bit of the same material, and extends into other environmental impacts of the railways.

I note that under "water" it deals mainly with water usage by the railways, and barely mentions their role in managing watercourses and drainage. In fact it generally interprets "environment" as what people are aware of around them. So it may have been a bit rushed - certainly some bits would benefit from more proof-reading, e.g.: "Freightliner, for example, has fitted stop-start technology in all its Class 66 and Class 70 fleet to reduce carbon, air quality and noise emissions when idling."

[broadgage]

Subject to the odd SHORT gap, London to Plymouth should be electrified in the near term, and eventually to Penzance.

The sea wall and the single track tunnel bores seem obvious examples; perhaps the bridge between St Budeaux and Saltash too if the opportunity of electrification is not taken to double track it  . 

How is acceleration from stops on battery compared to on main catenary power?   I would have thought battery drain was far higher from a start than if maintaining speed, and perhaps stations are not good places to miss out from overheads, Dawlish excepted!

Acceleration does indeed use more power than steady movement. If a train needs say 400 kw at line speed on level track, but say 1,000kw to accelerate when on OHLE, then it is a design choice as whether the battery can supply 1,000 kw, or some lesser figure.
Fast acceleration is possible with modern batteries, but it might be worth accepting the loss of say three minute between London and Plymouth if that means a cheaper or longer lasting battery. Or even a "middle ground" whereby the battery can deliver 1,000 kw but the driver is instructed to limit the discharge rate to 500 kw unless running late.

Short sections without OHLE could probably be traversed by coasting, but a battery would be vital in case some unforeseen event resulted in stopping in the dead bit.

[johnneyw]

"Up to 20 miles" does not sound very impressive for 5 tons of battery.

This is what struck me, especially when compared to the class 230.  Yes I'm sure there are all sorts of reasons for this but it's still not very good...or all that useful?

[TonyK]

The battery pack in a Tesla Model S weighs 544 KG. The train in question weighs more than 9.2 Teslas. Including the battery, the Tesla weighs 2.8 tonnes. A class 777 weighs 99 tonnes, plus 5 tonnes for the battery pack. In a Tesla, the battery represents 20% of the overall weight. In a Class 777, the proportion is less than 5%. I think I can see why the range is so limited. I would also imagine that the demand from a battery pack varies much more widely in a train than in a car, largely because of the difference in friction, and also because trains don't have steep hills and bends to cope with.

Some priest from Grantham once said that

An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force.

For trains, this means that the biggest demand is to get it moving, falling steadily as it accelerates more slowly, and very low once the train is going at line speed on the straight and level. A car will need a lot more input to overcome the greater friction of rubber on tarmac, and to keep speed around corners or uphill. Turning and climbing involve acceleration just to stay at the same speed. For motive power, a train will probably use battery power more efficiently than a car, but the battery size has to be sufficient to get the train moving in the first place. That will be a bigger drain proportionately than the Tesla will experience. Both train and car also have ancillary lights, aircon, and now WiFi and charging of phones etc. If the train is only going to switch to battery power at line speed, I should imagine that the add-ons will use as much power as the motors, but if it is going to stop and start at stations, the motors will need the lion's share. In any case, the specification will have to allow for an unscheduled stop and restart in the unelectrified section.

I am not a real physicist or engineer, btw, just a barrack-room one, and would appreciate it if someone would check my homework.

[bradshaw]

Roger Ford has covered this topic in his Informed Sources column for Modern Railways. Each month prior to publication he releases an ezezine email summarising the contents.

http://live.ezezine.com/ezine/archives/759/Informed%20Sources%20e-preview?p=1

Scanning the ezezine link should direct to the relevant edition of the magazine. May 2021 give a comparison using the body shell of DP2 and replacing power units by either batteries or fuel cells.

The ezezine gives an outline but the magazine article provides more details