Prototype Class 08e shunter successfully completes trials at Somerset quarry

A prototype battery-electric ‘08e’ shunter has successfully completed two weeks of trials at a quarry.

The plug-in shunter, designed to meet modern environmental, safety and noise pollution standards that a standard Class 08 cannot do, was taken to Whatley Quarry in Somerset, where it was operated by Mendip Rail.

During the trials, 08308 managed to push and pull trains of more than 1,000 tonnes from the bottom of the yard to the stone loading area, a journey that involved reverse curves, crossovers and steep gradients.

Positive Traction, the firm behind the ‘08e’, said the trial allowed engineers to gather data regarding battery life, revised uprated tractive effort, hill start capability and fast charging through regenerative braking. The results of these were all said to be “more than satisfactory.

Alistair Gregory, Director of Positive Traction said: “The ability to put the locomotive through its paces in one of the harshest aggregate sites has confirmed our expectations. The fact that it outperforms a standard 08 shunter whilst having the added benefits of all round visibility, modern heating and air conditioning, negation of working at height, modern quiet compressors, air drying equipment and improved lighting really shows that this design is well placed to support any industrial setting.

08308 was unveiled in October 2023 at Barrow Hill Roundhouse (RAIL 995). The 67-year-old shunter has had its English Electric 6KT 350hp diesel engine removed, along with the generator, radiator and familiar bonnet outline.

In its place, Positive Traction fitted a lower bonnet with aluminium ‘gullwing doors’ with batteries and control equipment inside. The result was a shunter with around 450hp and an increased tractive effort from 35,000lbf to 45,000lbf, similar to a Class 33.

Vincent Pitt, Operations Manager for Whatley Quarry said its teams were “curious and naturally apprehensive” before the tests, but added: “However, we are satisfied with the results of the trials and happy to have played our part in helping the team really see what their locomotive can achieve with loaded trains and with steep hills on our doorstep.”

The prototype has two batteries, also known as powerpods, with a total capacity of around 186W hours due to two slightly different batteries, although production units will have pods that produce more than 100kW hours each. Each pod also has a dedicated charger that allows all batteries to be charged in simultaneously.

While the ‘08e’ has a single ‘charging socket’ on all fitted pods, Positive Traction also says there is the option to ‘fast charge’, although that is limited by the maximum charging rate of the batteries. The prototype does not have a ‘fast charge’ option, and would be dependent on engineering and discussions with customers.

The loco is the same from the running plate down, while the cab has new front and rear windows and other new features such as roof-mounted heating, remote monitoring equipment and air-conditioning, although the original control desk and driving position remains.