Railway Electrification
Discussion
There's been a fair bit of fuss in the media over the possibility some rail routes in the north that were planned for full electrification, will only be partially electrified. Local government up here is up in arms, but DfT say it's not a problem as hybrid trains that are both diesel and electric can be used.
Can anyone tell me what the advantages of an electrified rail system are compared to diesel and why it is so important? From a layman's perspective,the hybrid proposal seems a nonsense, as if the train has to lug a diesel engine round anyway, you might as well just save all the money and complication on electrification and run diesel for the whole journey.
Can anyone tell me what the advantages of an electrified rail system are compared to diesel and why it is so important? From a layman's perspective,the hybrid proposal seems a nonsense, as if the train has to lug a diesel engine round anyway, you might as well just save all the money and complication on electrification and run diesel for the whole journey.
One of the problems with new electrification projects is that Brussels has bought in new regulations demanding a bigger clearance between the wires and, well, anything else. Sounds like a good thing but the old clearances have been used for years without problems and furthermore the more room you require beneath the roof of a bridge or tunnel the bigger the problem and expense. If it is a Listed structure then the problem becomes more like immovable object v. Irresistible force.
The greater the cost the fewer the projects.
The greater the cost the fewer the projects.
blueST said:
I understand that is one of the problems, but what are the advantages of electrification? What can be achieved that couldn't with more modern diesels? Essentially, why the push for electrification in the first place?
Big power stations are more efficient than trains at making electricity. Great big diesels thundering through suburbs are nosier than electric trains. Diesels in stations or towns sat pumping out smog isn't very nice.Basically its about moving where the dirt is made, or allowing the trains to run on renewable power via the grid. To the person on the train, the advantages are limited. electric motors may break down less but they are more vulnerable to power supply issues/saggy cables etc.
Electric trains are easier to maintain, cleaner and accelerate faster. The last part is very important on a path restricted railway like we have in the UK. I think I will let some of the insiders on this forum who know better answer in more detail though. They can run under towns and cities were diesel trains mostly do not or its minimised.
Dogwatch said:
One of the problems with new electrification projects is that Brussels has bought in new regulations demanding a bigger clearance between the wires and, well, anything else. Sounds like a good thing but the old clearances have been used for years without problems and furthermore the more room you require beneath the roof of a bridge or tunnel the bigger the problem and expense. If it is a Listed structure then the problem becomes more like immovable object v. Irresistible force.
The greater the cost the fewer the projects.
Yes some of the existing clearances are very tight at old bridges etc. Generally not a problem as you say until you throw in roosting birds and then you start having flash overs. Some non-electrified lines also have old station houses etc (privately owned) very close to the track and simply won't get the clearance unless they knock the house down.The greater the cost the fewer the projects.
I've been involved in these types of decisions for a few years so some round numbers for you:
Definable benefits:
The cost of energy for electric trains is around 50% of that for diesels (although about half of that saving is negated by the additional cost of maintaining the OLE and distribution network).
The cost of maintenance for electric trains is around 50% of that of diesels.
Reliability of an electric train is broadly double that of a diesel train
Maintenance intervals are much greater (c.15,000 miles for a diesel up to 30,000 miles for an electric). This has many knock on benefits such as - smaller fleet size for a given service intensity, smaller maintenance shed footprint so land and facility costs less.
Decrease in C02 emissions which reduces carbon footprint costs
Faster accelerating so able to run more intense service (greater revenue). This is not so much about quicker journey times per se, although it can do; its more about the ability to clear the junctions at crowed stations quicker on exit therefore allowing the next train in quicker.
Less definable:
Quieter
Passenger generally prefer them
Less external noise so seen as "better neighbours"
There are others, and of course the above are general so there will always be specifics that fall outside.
Hope that helps.
Definable benefits:
The cost of energy for electric trains is around 50% of that for diesels (although about half of that saving is negated by the additional cost of maintaining the OLE and distribution network).
The cost of maintenance for electric trains is around 50% of that of diesels.
Reliability of an electric train is broadly double that of a diesel train
Maintenance intervals are much greater (c.15,000 miles for a diesel up to 30,000 miles for an electric). This has many knock on benefits such as - smaller fleet size for a given service intensity, smaller maintenance shed footprint so land and facility costs less.
Decrease in C02 emissions which reduces carbon footprint costs
Faster accelerating so able to run more intense service (greater revenue). This is not so much about quicker journey times per se, although it can do; its more about the ability to clear the junctions at crowed stations quicker on exit therefore allowing the next train in quicker.
Less definable:
Quieter
Passenger generally prefer them
Less external noise so seen as "better neighbours"
There are others, and of course the above are general so there will always be specifics that fall outside.
Hope that helps.
Edited by nc107 on Thursday 27th July 16:27
[quote=mcdjl]
Basically its about moving where the dirt is made, or allowing the trains to run on renewable power via the grid.
Out of interest, could anyone tell me how many wind turbines and/or solar panels would be required to keep the trains running on those parts of the network already electrified? Also, where the power comes from on a cold still night?
Basically its about moving where the dirt is made, or allowing the trains to run on renewable power via the grid.
Out of interest, could anyone tell me how many wind turbines and/or solar panels would be required to keep the trains running on those parts of the network already electrified? Also, where the power comes from on a cold still night?
Yertis said:
mcdjl said:
Basically its about moving where the dirt is made, or allowing the trains to run on renewable power via the grid.
Out of interest, could anyone tell me how many wind turbines and/or solar panels would be required to keep the trains running on those parts of the network already electrified? Also, where the power comes from on a cold still night? One other advantage of electrics is that you can use regenerative brakes to feed power back into the wires which can then either be used by another train (the old Manchester to Sheffield via Woodhead line did this in the 1950s!) or fed back to the grid to power houses etc. With a diesel it's wasted as heat either via the brake discs or resistor grids if rheo brakes are fitted. AIUI, modern electric trains make little or no use of the brake pads other than as parking brakes when they're stopped at stations etc.
I suppose you could fit large batteries/motors to absorb/re-use the braking energy on a diesel train, but again, AIUI, no UK train has or is planned to have this technology, other than the test battery/overhead wire train that was tried in East Anglia recently.
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