Tesla batteries to power Hybrid Class 08 shunter
METEOR Power Limited has created a ‘First in Class’ hybrid Class 08 shunter in an innovation competition to convert a diesel shunting locomotive to a modern hybrid electric system.
The competition was run by the Department for Transport (DfT).
When the company was awarded the contract, it took six weeks to find a suitable Class 08 loco as the most suitable test bed – a task assisted by the NRM associate curator Bob Gwynne, who claimed Wolverton Works had several of the class.
After Gemini Rail Services took over operations at Wolverton Works in November 2018, they inherited two Class 08 shunters – Nos. 08629 and 08649 which were surplus to requirements.
Both locomotives had tripped the Royal Train between the Works and Wolverton Centre Sidings for more than 25 years.
No longer registered for use on Network Rail, it was decided No. 08649 would be the donor, having been stored unserviceable after suffering a damaged crankshaft.
Heavy corrosion
Leaving Wolverton on
January 7 it went the short distance to Silverstone to a small workshop with one track panel inside. The other shunter was relocated to the Chinnor & Princes Risborough Railway.
Component removal on
No. 08649 began on January 9, with the team discovering a number of key parts missing plus heavy corrosion around the battery boxes, the cab roof, walls and floor.
Meteor had no prior knowledge of the class and sought rail industry advice, together with buying several original BR and English Electric training books to assist them.
Mike Edwards, of Meteor, said: “We’ve had to rely on the experience and advice of others to guide us, and our task has been made significantly harder as we had to work out which pieces of the jigsaw we had to remove and in what order to gain access to the parts we needed.
“As such, the advice from industry experts has been invaluable in understanding what the different components are and how they interact.”
Colleague Rob Bruerton added: “Since taking delivery of the loco we were working flat out stripping things down in preparation for removing the damaged 92-litre engine and preparing the build and testing of the first phase of our electronics.”
This testing took place on February 3 when No. 08649 moved backwards and forwards under electrical power for the first time powered by an external fixed shore supply. It was controlled by a Meteor-designed electronic controller.
Mr Edwards added: “Removing the engine took a bit longer, with far too many nuts, bolts, pipes and so on that hadn’t seen a spanner for 60 years so it was definitely harder work than expected.
“Eventually we had to resort to cutting a few of the larger nuts as no amount of heat or leverage was doing the job. The end result was that on February 21 the old engine and generator was removed and a start could be made installing the new alternator and battery pack parts before finalising the wiring.”
Railway history
Bob Gwynne is following and documenting progress.
He explained: “Given this project had the potential to create railway history and is one of the ways the railway could reduce its carbon footprint, we thought it worthwhile to try and record the development of this interesting prototype.”
The hybrid system comprises of a Euro stage 3A compliant John Deere 6.8-litre diesel engine connected to an alternator to recharge the battery pack, which has a combined storage capacity of 300 kWh.
The battery pack consists of modules taken from Tesla
Model 3 cars. Each of the four batteries can, in theory, be recharged in under an hour.
The engine will be improved to be better than Euro Stage 5 standards using technology from sister company Motive Zero.
Meteor Power’s bespoke control systems will drive the auxiliary systems such as compressors, vacuum pumps and drive the original traction motors.
Regenerative braking is included in the new design allowing it to help recharge the batteries while coasting or slowing down during braking.
The driving controls remain unaltered, but with only 24 volts under the control desk rather than the current design of 400 volts, it is safer, and approvals should be easier to achieve.
Mr Edwards’ family has history with engineering innovation going back more than 200 years, and in 1886 supplied the steam engine for the Turkish Ottoman Navy’s Nordenfelt steam submarine.
The hybrid locomotive was completed by the end of March, and was due to move to the Chinnor & Princes Risborough Railway in April for comparative testing to establish the battery range and other performance statistics.
Tests postponed
Sister engine No. 08629 would undergo similar tests using diesel power to establish a direct duty cycle comparison. However, these tests have been postponed because of the Covid-19 outbreak.
Both the ex-Wolverton shunters will feature in the postponed diesel gala in the autumn, and subject to a relaxing of Covid-19 restrictions, details will be announced in May.
This type of hybrid shunter may be ideal for use on heritage railways where houses have been built near to engineering and servicing bases, and where reduced emissions and noise will be welcomed by neighbours.