What?

That's the sound they are supposed to make???

Mine just insults me loudly when I open it! :catangry:

So given all this, what is driving the discontinuous discussion?

Until about 10 years ago, discontinuous electrification wasn't really a thing. I would argue that outside the UK, it still really isn't. Yes, some railways have a single discontinuity to deal with a specific, unusual challenge. A good example might be a lifting bridge where providing moving OLE is very technically complex. But these are few and far between, and crucially, usually only at one location on a route.

Since then we have learned a lot of lessons and begun to deliver electrification at lower costs. But still the taint remains, and so people go looking for silver bullets to allow railways to be decarbonised at low capex. This is understandable, but also deeply damaging.

Ian Walmsley, a rolling stock expert in Modern Railways magazine coined the term "Disingenuous Electrification" to indicate how it is used to avoid taking mature decisions about electrification.

In summary, the discontinuous concepts that have engineering and economic merit are:

- A single discontinuity to deal with a problem for which there is genuinely no engineering solution;
- Last-mile branch line capability in coordination with continuous electrification on the mainline, expecially for freight;
- Temporary discontinuities as part of a staged and coordinated rolling programme of electrification.

Any other use should be subject to hard-nosed whole life cost analysis, in comparison with continuous electrification.

This thread has hardly scratched the surface of the topic; there are a number of resources I would recommend to understand the benefits of continuous electrification. The RIA "Why Rail Electrification?" & "Electrification: The Facts" papers (disclosure: I was a co-author on both) are a good starting place.

riagb.org.uk/RIA/Newsroom/Publ…
riagb.org.uk/RIA/Newsroom/Publ…