Overhead DC electrification - a potential solution to the conundrum of EMUs?

If preserved EMUs are to run on any heritage line, other than being hauled by steam or diesel locos, batteries would seem altogether more practical than OLE. Given the low speeds and shortish distances, the energy requirement for a single run would not be great. A decision would be needed between batteries large enough for a full day's operation, with overnight charging, or small batteries and allowing time for charging between runs.

 

Like what GWR are doing with some 40 year old District line EMU's on the Greenford line...

 

That is a practical trial on a short lowish-speed line. Its success (subject to possible teething troubles) or failure will certainly help to inform possible application of batteries elsewhere. The trial installation of batteries on a Hitachi 800-series train is a rather different kettle of fish.

 

The Greenford trial is as much about the fast charging technology as the usefulness of batteries in this sort of application. As such there may be useful lessons and technology that could be applied to heritage line situations. Not cheap, but doable.

 

I wonder how many kilojoules of energy would be needed to run, say, a 4-EPB loaded to 30% over a return trip of twenty miles?

 

I am surprised no mention has been made of the E4 loco at North Tyneside's Stephenson Steam Railway. I understand it is fully operational and powered by a wagon full of batteries close coupled. Not a long line but has a reasonable hill to negotiate.

 

You could have 3 or 4 wagons, one in use and the rest on charge and keep swapping them over.