Electrification
Discussion
So does that in turn lead to be able to run more frequent, or bigger, trains?
I was watching the local news recently when they were talking about postponing the electrification of the line to Sheffield, cue a film of lots of sad-looking people standing in a packed carriage, and I wondered why the fact that they're not electrifying it yet has any bearing on the trains being packed. Is it not economically or logistically possible to run more diesel trains to alleviate the crowding? The passengers don't generally care about what powers the train, just whether they've got somewhere to sit (or even stand).
I was watching the local news recently when they were talking about postponing the electrification of the line to Sheffield, cue a film of lots of sad-looking people standing in a packed carriage, and I wondered why the fact that they're not electrifying it yet has any bearing on the trains being packed. Is it not economically or logistically possible to run more diesel trains to alleviate the crowding? The passengers don't generally care about what powers the train, just whether they've got somewhere to sit (or even stand).
The cost per vehicle should be lower, as electric trains are simpler than diesel ones both to build & maintain. This should allow more vehicles to be built for the same cost. The other big thing, as others have said, is smoothness/noise - on the Midland Mainline, the fast trains are either a 1970s HST, where you've got 2 power cars that basically just carry an engine/generator and some bikes or a Meridian unit that carries passengers in each coach but has lots of noise/vibration from the engines underneath. Contrast that to the Pendolinos on the west coast line - every vehicle carries passengers but there's very little noticeable traction noise & no vibration - this means you can have more/better payload for the same length.
This all, of course, depends on the electrification being specced to cope with the possible number of trains - IIRC, the East Coast line south of Peterborough needs to have a certain %age of trains diesel hauled in the rush hour because the wiring can't cope. The 1960s/70s wiring on the West Coast can cope with pretty much anything, hence why you see long trains of containers being dragged up Shap/Beattock by electric locomotives. Electric freight trains are also significantly faster point-to-point BTW, so need less line capacity & allow more space in the timetable for passenger trains to run.
This all, of course, depends on the electrification being specced to cope with the possible number of trains - IIRC, the East Coast line south of Peterborough needs to have a certain %age of trains diesel hauled in the rush hour because the wiring can't cope. The 1960s/70s wiring on the West Coast can cope with pretty much anything, hence why you see long trains of containers being dragged up Shap/Beattock by electric locomotives. Electric freight trains are also significantly faster point-to-point BTW, so need less line capacity & allow more space in the timetable for passenger trains to run.
"Regen" braking!!
As a Rail network is scheduled, and runs a relatively limited service, you pretty much can dump energy back into the network when one trail brakes for a station, and use it to accelerate another away from it's last stop ;-)
Just the savings in brake components alone is massive, let alone the effective fuel saved
(A 410 tonne Intercity trail travelling at 125mph has around 640MJ of energy stored in it's mass! For people who like sciency things compared in simpler terms, that's enough energy to power a typical UK household continuously for over 2 weeks!)
As a Rail network is scheduled, and runs a relatively limited service, you pretty much can dump energy back into the network when one trail brakes for a station, and use it to accelerate another away from it's last stop ;-)
Just the savings in brake components alone is massive, let alone the effective fuel saved
(A 410 tonne Intercity trail travelling at 125mph has around 640MJ of energy stored in it's mass! For people who like sciency things compared in simpler terms, that's enough energy to power a typical UK household continuously for over 2 weeks!)
Edited by anonymous-user on Tuesday 14th July 13:16
AJLintern said:
Why don't they use a third rail system? You'd think it would be a lot cheaper to install, considering the number of bridges they've had to rebuild to accommodate the height of the overhead cables. Is it just because that's what the Hitachi trains use...? Safety? 
Level crossings, I'd guess.Speed is also a factor - the record for the fastest train using third rail is 108mph, held by a BR Class 442 on the Southern region (interestingly, we still hold three of the four 'conventional' rail speed records, the others are 126mph for steam, and 148mph for diesel).
Trains that take power from an overhead cable are already capable of travelling at 200mph on a regular basis, and a French TGV set holds the record at 357mph.
Trains that take power from an overhead cable are already capable of travelling at 200mph on a regular basis, and a French TGV set holds the record at 357mph.
IroningMan said:
Isn't the performance difference a function of the power supply? Why couldn't third rail be the same power supply as overhead? And surely it uses less infrastructure, not more?
Not picking a fight - just curious.
Power delivery. OH runs at a higher voltage. Look at a starter motor cable on a car, and a power lead for a kettle. Same amount of power but the kettle uses less copper, smaller switches.Not picking a fight - just curious.
So you can use more powerful motors and multiple trains and less likely to electrocute people with OH.
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