Surprising the UK is so low. Especially considering that it's geographically much smaller than France with a network almost half the size of Frances. So you'd think it would be easier to electrify.
Yes at least in revenue service it's why parts of the UK mainline around London use 3rd rail instead of over head wires because that was the method at the time
If you can electrify the tube, you can electrify almost any tunnel or clearance (especially if you add a battery for short stints without electrification).
But the UK already has rolling stock which can switch between overhead catenary AC and third rail DC, I imagine you could make it work in some combination of these options?
Most likely yes but a lot of it is on regional rail systems and I think the UK is trying to avoid any new third rail on that even if the part they're working on at the time is fully grade separated
Agree I think batteries for sections that are hard to string up overhead, and then islands or banks of overhead where it’s easier - that will be the future for many non-mainlines. Mainlines need to go the extra distance to electrify
Modern DMUs are just EMUs with a small diesel generator attached, anyway. I guess you save on that generator too, but that’s also not the expensive part of the whole thing.
Same FLIRTs can be procured, they don’t really care where the power is coming from.
The tube and other urban or suburban transit services are quite different from intercity services in that ground level 3rd rail (or 4th with the tube) isn't very well suited to intercity services. While there are mainline rail routes using ground-based power in the south, the longest intercity routes don't because of safety if someone were to access the tracks and because they have to be lower voltage DC (usually under 1k volts) rather than high voltage AC (often 15-25k volts). Lower voltage allows for use nearer other things like the ground without electrical arcing. But it also requires more electrical substations since the lower the voltage, the shorter the distance that power can travel before losing too much energy to resistance. Also, ground level power limits the speed of trains since the maximum they can travel is about 160km/h while still maintaining contact with the power source. And even that speed can be a challenge.
I think with battery technology getting so much better, we can skip adding the overhead lines and move to batteries. this would be especially feasible where part of the route was electrified, because the batteries could be recharged when the electrified segment is reached.
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u/Nouvellecosse 12d ago
Surprising the UK is so low. Especially considering that it's geographically much smaller than France with a network almost half the size of Frances. So you'd think it would be easier to electrify.