It appears from the interview with Neil Drury of SWR at 36 to 39 minutes of the following Green Signals Episode 57 that the plan for the West of England railway is for third rail sections which are only switched on and live when there is a train in section that needs it.
Heard that interview although have to wonder how much 3rd rail would cost down the WoE as you will need a lot of extra kit and interface to the signal system and presumably remote control as well to avoid stranded trains situation although with some battery backup that might simplify things.
Or Hurst Green to Birchden Jn would have closed, which I believe was an option in the late 60s? Either way, Oxted would have gone electric.
Lieberr roof air con units are nearly 40kw in cooling mode albeit as long as train has been pre cooled it shouldn't need to run flat out then you have other aux loads. So in a worst case scenario it could easily use more than 20kW/carriage given you have other auxiliaries as well. Hitachi BEMU trials in Japan nearly a decade ago showed that hotel load was quite a factor in range when operating at the worst case upper and lower operating temp albeit those trains only had a 360kW battery / 2 car. Im wondering if managing state of charge (SoC) is exercising the standard setters and regulators at the moment in how to define what the operational characteristics that a BEMU has to achieve. ie how low should SoC go. The battery suppliers tell us that life is extended running at 20-80% range but presumably that doesn't prevent the odd excursion below that level. So like planes
There's a very simple solution to that - put a third rail section in at each station. See the following thread for lots of information.
Third rail in stations is ISTR the most common situation for injuries and deaths, - so not much chance of that.
or alternatively a charging solution* at the terminus, or a larger battery
Worth reading the thread I highlighted- "Battery 450s replacing 159s on West of England Line". Third rail at/approaching and leaving stations; energised when the train is in section. If this approach could work for Worting Junction - Exeter, it could work for North Downs Line, Marshlink etc.
Yes, but the other expectation must be that the 19% of the Southern region which isn't electrified never will be.
Its an ideal route for BEMUs with electrification at the remote ends and a section in the middle for a power boost. This like multiple routes that part operate under the wires should be ideal candidates for a standard unit procured nationally by GBR.
19%? By what measure?
Which in terms of the impact of diesel use irrelevant. The three main routes, BML, SWML and Portsmouth direct probably account for over half the total.
Wokingham to Ash is 12 miles, and Shalford to Reigate is 17 miles.
Ashford to Ore should be sufficient looking at that. Even if 50 miles is in range, I think there should be some charging means available at Uckfield, or at least close to that end, for resilience. Also worth noting the line is not the flattest going, it has to navigate the High Weald with some notable gradients, so power demand would be higher than 50 miles on a relatively flat route like the Marshlink.
Remembering that whatever goes up must come down, although the power drain is larger on a hilly line the opportunities for energy recovery are also similarly larger. Obviously the laws of themodynamics mean you'll still have a greater net expenditure of power if you are applying and recovering than coasting (impossible to achieve 100% efficient transfer of energy type), but the difference isn't as large as is maybe being suggested.
Given that most recent and all new (main line) EMU designs have provision for mounting an pantograph, in a DC-only region, it would be worth fitting a pantograph optimised for static charging so that short overhead conductors could be fitted in likely emergency locations, (e.g. a turn-round station, a busy junction signal). The feed could be 25kV (c. 5MW) from a DNO connection or even DC if the transformer primary was suitably protected.
