Battery Use In Class 777 Trains
In the November 2022 Edition of Today’s Railways, there is an article about Merseyrail’s new Class 777 trains.
This extract describes the use of batteries on the trains.
All units have small batteries for moving independently around depots. Seven units are now being fitted with larger 160 kWh Lithium Titanate Oxide (LTO) batteries and associated traction converter in the leading coaches in space that could also be taken up by a transformer and AC equipment if some units were converted to dual /Battery operation (there would not be the space for tri-mode AC/DC/Battery operation). The cooling system for the battery lies has been roof-mounted. The battery boxes have been supplied by ABB and the batteries themselves by Toshiba. 777002 has been converted as a trial to prove the concept in 2021 but has now been converted back to an EMU.
Stadler explained that the battery life would normally be 8-10years but if the units are only used in battery mode for the 2 km between Kirkby and Headbolt Lane then that is expected to be more like 15 years. However the batteries have the potential to do around 40 miles, so Bidston-Wrexham is possible, with a 15 minute recharge time required at Wrexham before returning. Maximum speed in battery mode is 60 mph compared to 75mph as a DC EMU.
This is a map of how the network might look.
These are the lengths of routes, where the Class 777 trains might run on batteries.
- Bidston and Wrexham Central – 27.5 miles – Possible with a charge at Wrexham Central.
- Canada Dock Branch – 4.7 miles – Dual-voltage trains.
- Chester and Crewe – 21.2 miles – Possible with a charge at Crewe
- Chester and Runcorn East – 13.1 miles – Possible without recharging
- Ellesmere Port and Runcorn East – 10.8 miles – Possible without recharging
- Hunts Cross and Manchester Oxford Road – 27.1 miles – Possible with a charge at Manchester Oxford Road
- Kirkby and Wigan Wallgate – 12.1 miles – Possible without recharging
- Ormskirk and Preston – 15.4 miles – Possible without recharging
Note.
- There are a lot of possibilities to use Class 777 trains with batteries.
- Charging might be needed at only three stations; Crewe, Manchester Oxford Road and Wrexham Central.
- Four route extensions are possible without charging.
Merseyrail are going to have plenty of uses for the sixty trains, that they have on option.
Train Efficiency On Battery Power
In an article in the October 2017 Edition of Modern Railways, which is entitled Celling England By The Pound, Ian Walmsley says this in relation to trains running on the Uckfield Branch, which is not very challenging.
A modern EMU needs between 3 and 5 kWh per vehicle mile for this sort of service.
Consider.
- The Class 777 train is a four-car train, but is only five metres longer than a three-car train.
- So applying Ian’s formula, it seems that to do forty miles, the battery will be between 480 and 800 kWh.
- If it is mathematically like a three car train, it seems that to do forty miles, the battery will be between 360 and 450 kWh.
A 160 kWh battery is obviously too small.
But the extract says that the batteries are fitted in the leading coaches, so can we assume that each battery train has two leading coaches and two batteries.
Does the battery train have a battery capacity of 320 kWh?
- Assuming it does, it would appear that after using Ian’s formula for a four-car train gives a figure of 2 kWh per vehicle mile.
- A three-car train gives a figure of 2.67 kWh per vehicle mile.
I suspect that these low figures are down to good engineering and a very efficient electrical system on the train.
But then I did write Stadler FLIRT Akku Battery Train Demonstrates 185km Range.
Conclusion
These trains are going to set new standards for a city metro.
The Anonymous Widower 
I applaud their proposals but they need DfT to buy into it and omens aren’t good and also they actually need to get one into service only 3 years late so far.
This was an interesting presentation about the results of the recent battery trial that gives good confidence about what can be achieved
https://liverpoolcityregion-ca.public-i.tv/core/portal/webcast_interactive/567938/start_time/951000
Comment by Nicholas Lewis | October 15, 2022 |
I suspect there is a person in the Department of Transport, who is totally against electric trains unless they are powered by 25 KVAC overhead wires.
After all I rode the Bombardier/Network Rail demonstration train in February 2015.
Progress on anything else is incredibly slow and more third-rail is banned.
I doubt, it is a politician, as there have about one per year in this time and some have even been a bit technical. They can’t all believe this do nothing policy, especially when France, Germany, Japan and the US are embracing it.
Comment by AnonW | October 15, 2022 |
They should be embracing BEMUs saves on the infrastructure costs which after GWEP its hardly a surprise where NR managed to trash all the efforts of dedicated engineers in BR to get electrification done at a competitive price.
Comment by Nicholas Lewis | October 15, 2022
Interestingly an Rail Gazette article of 22 September concerning the seven Class777 battery conversions remarks that
“The IPEMU battery can be charged from the third rail to provide a range of 25 km on non-electrified routes at a maximum speed of 80 km/h.”
Comment by fammorris | October 15, 2022 |
I have done a bit of reverse calculation in a new section of the post and I have come to the conclusion, that these are super-efficient trains. I once asked one of Greater Anglia’s senior drivers, what was the design speed of a Class 755 train and he indicated they were good for 125 mph, which they can’t do in East Anglia. Those trains certainly ride very well, so have they put it all together in a metro train?
Comment by AnonW | October 15, 2022 |