Why aren't all lines electrified?

[Joshrowlands]

Hi Im quite new to trains and the rail network since about July I have had a big interest in trains and the rail network I know quite a lot but still have a lot to learn and a lot of questions being the main reason I joined this amazing website.

One question I do have however is how come only certain lines are electrified? Arent electrified lines better than normal lines and aren't eletric trains more efficient than diesel? If so why aren't all lines electrified and if not then why aren't they more efficient?

If someone could give me some pro's and con's about electrifying lines and why all of them aren't that would be great and so would extra details, thanks guys

 

[Ironside]

Hi Im quite new to trains and the rail network since about July I have had a big interest in trains and the rail network I know quite a lot but still have a lot to learn and a lot of questions being the main reason I joined this amazing website.

One question I do have however is how come only certain lines are electrified? Arent electrified lines better than normal lines and aren't eletric trains more efficient than diesel? If so why aren't all lines electrified and if not then why aren't they more efficient?

If someone could give me some pro's and con's about electrifying lines and why all of them aren't that would be great and so would extra details, thanks guys

Electric trains are faster eccellerating, more reliable, and cheaper to build and run than diesel equivalents. The reason all lines arnt electrified currently is part historical; in the 1950s investment was made in diesel more than electric; and the cost and will to electrify lines. It can be expensive or very expensive to electrify a line depending on how many bridges and tunnels need to be resized to fit the cables. It may therefore take 40-50 years to get back the money invested, depending in part on how busy the line is. As the decision to electrify a line is also a political one, the govement of the time has to think its a good idea as well before any investment can take place.

So to answer your question, some lines have been considered worth the investment and others have not either because they weren't considered worth the investment, or there wasn't the money available to make the investment.

 

[Taunton]

The trains themselves are cheaper to build and more efficient when running, but there is a lot of cost in all the equipment to get the electricity from the power station to the rain, which diesel trains do not have. It's not only the 3rd rails and overhead wires, but also substations, connecting up to the electricity grid, which may have to be reinforced itself, etc. The cost of all this then has to be spread over the trains running, which may be worth while on busy main lines but not nearly so much on secondary lines which don't have many trains.

Freight trains are a particular problem because they often run to odd places with few trains, where it is not worth having this electric provision, even if the bulk of their route is on an electric line they would need something different at the end. Freight trains also tend to change their route or whether they run at all much more frequently than passenger trains, what is a busy route at one time is often not a few years later. Finally, freight terminals where you are swinging freight on and off wagons are not a good place to have high powered wires just above.

The 3rd rail, extensively used south of London and in a few other places, was quite cheap to install, but overhead wires are something else, they generally don't fit under the bridges and tunnels without a lot of work, and the engineering costs of putting it in can be very substantial, and in a few places impossible.

 

[NotATrainspott]

The rail network is edging further and further towards an all-electrified future. Plans exist to electrify the two main unelectrified main lines out of London - the Midland and the Great Western - as well as a smorgasbord of regional and commuter lines around the country. The logical conclusion of this process is that only properly rural lines are left without wires, e.g. the West Highland or Cumbrian Coast lines, which account for so little of the rail traffic that it may be easier simply to electrify them so that there is no need to acquire a small fleet of diesel passenger trains. Switzerland runs an entirely electrified rail network so it is certainly possible, although we do not have the same need for fantastic hill-climbing ability as they do.

 

[yorkie]

One question I do have however is how come only certain lines are electrified?

Could you put together a business case for electrifying rural lines such as the West Highland Line?

 

[Starmill]

Could you put together a business case for electrifying rural lines such as the West Highland Line?

Nobody could - and the West Highland Line is clearly not going to be electrified any time soon. But projects without business cases can still advance *cough* Borders Railway *cough* *cough*

 

[Murph]

Something to consider for electrification is that the national grid is currently so heavily loaded that they are using locomotive sized diesel engines (1-2MW each, Valenta-size-ish) to supplement the big generating stations during periods of peak demand. These diesels are more efficient than the oldest big stations, so used in preference to them.

So, during peak demand, a modern diesel loco under power is actually more efficient than an electric, in a round about way, as it doesn't have long distance transmission losses from a very similar engine. Where the electric always wins out is at zero or low power demand, where a diesel loco is less efficient. The bottom line is that it's sometimes a much narrower green margin between a modern diesel and an electric. During periods of low demand on the grid, of course, it's better.

The case where electric can almost always win out for classic UK loading gauge is total power. Electric can push out up to around 6000hp, but max diesel is around 3500hp. Max power isn't everything though, as 4500hp will do a record of 147mph after ETH loss, or normal 125mph after ETH; or 3000hp-ish works fine for a lot of UK freight.

 

[LNW-GW Joint]

It costs about £1 million per single track kilometre to electrify a line.
So the current 1000 (route) miles approved over the last few years will cost something like £4-5 billion.
That has to be weighed up with all the other government capital spending (building hospitals, aircraft carriers etc).
There's a good description of where the costs come from in the Network Rail Electrification RUS: http://www.networkrail.co.uk/browse...ation strategy/networkrus_electrification.pdf
Check out Chapter 3 (Baseline) particularly. Actual wiring is only about 30% of the overall costs.
This was written in 2009, before any work was started, and the actual costs are turning out significantly higher than predicted.

 

[edwin_m]

In Switzerland pretty much every railway is electrified, including some really minor ones that would have closed decades ago if they had been in the UK. I believe this (the electrification not the keeping open) is down to Switzerland having lots of cheap hydroelectric power but no coalfields or other source of fuel within the country.

In the UK although we had a lot of coal this was seen as a reason to keep building steam locos well into the 1950s. Some electrification was agreed then but the rest of the network went over to diesel even though we had to import the fuel (North Sea oil not appearing until the 1970s).
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The 3rd rail, extensively used south of London and in a few other places, was quite cheap to install, but overhead wires are something else, they generally don't fit under the bridges and tunnels without a lot of work, and the engineering costs of putting it in can be very substantial, and in a few places impossible.

Installing an overhead line may be more expensive than installing a third rail but when you consider the total costs over the lifetime of the equipment the choice is much less clear cut. Third rail needs a substation every few miles and usually high voltage trackside cables linking them together, whereas 25kV overhead line needs virtually nothing else in between the grid feeders which are tens of miles apart. All that equipment needs more maintenance too, and to cap it all the third rail uses about 30% more energy for equivalent performance and trains using it are limited in maximum speed and power.

 

[Altnabreac]

Nobody could - and the West Highland Line is clearly not going to be electrified any time soon. But projects without business cases can still advance *cough* Borders Railway *cough* *cough*

50% of the Borders line (Edinburgh - Gorebridge) has a great Business Case.

Even the section south of Gorebridge is likely to generate a positive return because it is part of a regional planning iniative to build more homes in the central borders and increase commuting into Edinburgh.

The fact that traditional business cases can't capture these sorts of benefits is more a problem for them than for the Borders line.

I think a few people will be surprised how successful the Borders line will turn out to be.

As I've said before it's not just business cases you need to look at but whether a line fulfils Altnabreac's golden rules of rail reopening:

Altnabreac's Golden Rules of successful rail reopening. Lines must:

• connect a town of 10,000 plus population currently isolated from the rail network,
• to a major employment centre (usually a city of 300,000+ population),
• in a time of 60-75 minutes (or less), that is competitive with the equivalent road journey.

Border's rail will fulfill these quite happily and generate loads of traffic from Midlothian straight away, while Borders passengers will take more like 10 years to ramp up as house building, travel to work and economic growth patterns take time to adjust to the new infrastructure.

 

[Taunton]

Third rail needs a substation every few miles and usually high voltage trackside cables linking them together, whereas 25kV overhead line needs virtually nothing else in between the grid feeders which are tens of miles apart.

I've discussed this point before, but the truth is that whereas third rail does have a substation every few miles, with 25Kv you need a substation (ie a transformer/rectifier unit) on each train, because (simplistically) the motors don't work on that voltage but at one which, quite nicely, is that used directly from the third rail. And in a 12-car train you will have three such substations on the train. You have just transferred the transformers and rectifiers from lineside buildings to underneath each motor coach.

I am aware that power electrics have reduced the size of these train-mounted transformer/rectifier substations in recent years, and what used to add about 8 tons to the weight of each motor coach is now something that can be pushed underneath with a small fork-lift, but this miniaturisation is equally applicable to lineside installations as well. The reason why much of the Southern has large lineside substations along the way is that they were installed in the 1930s-60s, when that sort of thing was the standard.

You still need lineside substations as well with 25Kv, because the grid doesn't work at that voltage.

This is all condensing the situation, of course, but I'm addressing our original poster who I gather is coming new to the subject, rather than regurgitating Dover's classic professional textbook on the subject!

Altnabreac's Golden Rules of successful rail reopening. Lines must:
connect a town of 10,000 plus population currently isolated from the rail network,
to a major employment centre (usually a city of 300,000+ population),
in a time of 60-75 minutes (or less), that is competitive with the equivalent road journey.

Separate discussion, but I would add, or even put first, that the stations along such routes must be really where the population is, rather than just sort-of near. Take as an example two comparably-sized cities, Edinburgh and Bristol. The first has its major station right in the centre, and a second important one to the west. Bristol meanwhile has its main station well beyond walking distance from the office, retail and other commercial areas of the city which generate rail journeys. The difference in rail commuting levels couldn't be more marked between the two, people just don't commute or go shopping on Bristol's rail system to anything like the same extent for local journeys - it becomes less relevant the longer the journey is.

 

[HSTEd]

Because the Government is not willing to pay for it.

 

[Altnabreac]

Separate discussion, but I would add, or even put first, that the stations along such routes must be really where the population is, rather than just sort-of near. Take as an example two comparably-sized cities, Edinburgh and Bristol. The first has its major station right in the centre, and a second important one to the west. Bristol meanwhile has its main station well beyond walking distance from the office, retail and other commercial areas of the city which generate rail journeys. The difference in rail commuting levels couldn't be more marked between the two, people just don't commute or go shopping on Bristol's rail system to anything like the same extent for local journeys - it becomes less relevant the longer the journey is.

Agreed, good points.

 

[Xenophon PCDGS]

Why were the Southern Railway so keen upon electrified lines in comparison to the other large railway companies?

 

[edwin_m]

I've discussed this point before, but the truth is that whereas third rail does have a substation every few miles, with 25Kv you need a substation (ie a transformer/rectifier unit) on each train, because (simplistically) the motors don't work on that voltage but at one which, quite nicely, is that used directly from the third rail. And in a 12-car train you will have three such substations on the train. You have just transferred the transformers and rectifiers from lineside buildings to underneath each motor coach.

I am aware that power electrics have reduced the size of these train-mounted transformer/rectifier substations in recent years, and what used to add about 8 tons to the weight of each motor coach is now something that can be pushed underneath with a small fork-lift, but this miniaturisation is equally applicable to lineside installations as well. The reason why much of the Southern has large lineside substations along the way is that they were installed in the 1930s-60s, when that sort of thing was the standard.

You still need lineside substations as well with 25Kv, because the grid doesn't work at that voltage.

This is all true but doesn't address either the need for trackside feeders or the increased energy loss due to much lower voltage and therefore greater currents between the substations and the train. Yes you need substations to go down from Grid voltages to 25kV, but you need them also at similar spacings to go from Grid voltages to the trackside feeders, typically 33kV, which then feed another set of substations to go down to 750V.

The "substations on the train" can also be sized exactly to meet the demands of the train, unlike lineside substations which have to be big enough to cope with the occasional situation where two or three trains are drawing power at the same time.

Generally speaking the AC systems are more economical over longer distances, when the number of trains is less than the number of substations, currents flow over longer distances and high-current local power supplies are less common. Just about every mainline railway that wasn't already tied to using a lower voltage system has gone for 25kV for new electrification schemes from the 1950s onwards.

 

[QueensCurve]

One question I do have however is how come only certain lines are electrified? Arent electrified lines better than normal lines and aren't eletric trains more efficient than diesel? If so why aren't all lines electrified and if not then why aren't they more efficient?

Electric Trains are lighter and therefore cheaper to run and have better performance.

Against this there is the capital cost of electrification and the additional cost of maintaining the infrastructure. A certain minimum level of service is therefore needed to get a return on the investment.

Hence lightly trafficked lines do not justify electrification.

In so far as I am aware, the only country to have adopted a policy of 100% electrification is Switzerland. That reflects the fact that they are self-sufficient in electricity but coal and oil have to be imported.
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So, during peak demand, a modern diesel loco under power is actually more efficient than an electric

But an electric train doesn't have to carry around the weight of the engine or it's fuel.

 

[Hornet]

Hi Im quite new to trains and the rail network since about July I have had a big interest in trains and the rail network I know quite a lot but still have a lot to learn and a lot of questions being the main reason I joined this amazing website.

One question I do have however is how come only certain lines are electrified? Arent electrified lines better than normal lines and aren't eletric trains more efficient than diesel? If so why aren't all lines electrified and if not then why aren't they more efficient?

If someone could give me some pro's and con's about electrifying lines and why all of them aren't that would be great and so would extra details, thanks guys

http://www.bbc.co.uk/history/british/modern/marshall_01.shtml

This article is about the Marshall Aid Plan after WWII, and is a damning indictment of the post War Government's squandering of those funds, especially with regards to the UK and Germany's use of those funds in relation to the Rail Industry.

 

[Bletchleyite]

Could you put together a business case for electrifying rural lines such as the West Highland Line?

Ask the Swiss, though admittedly they did it so long ago that it was the high cost of steam vs. the low cost of electricity. Bring in other technologies like diesel, hybrids and batteries, and the case soon fails.

Neil

 

[apk55]

I could well see large parts of the UK network being totaly electrified in the next few years, such as SE england. Also I could see all main lines with a frequent service of large trains justifing electrification.

However in the remoter parts of the country with lightly used branches (such as the Central Wales line) it harder to justify the cost of electrification against the cost of a small fleet of diesel units, even if they are rather ineffiently used.


A few diesel locos would probably still be required for working industrial branches, engineering trains and rescue duties although these probably could be bi mode Electro diesels such as class 88 possibly with only limited power off line.

 

[HSTEd]

I can put together a business case for electrification of the West Highland Line, but unfortunately it revolves around such old fashioned concepts like caring about the Balance of Trade and so forth.

 

[GRALISTAIR]

Why were the Southern Railway so keen upon electrified lines in comparison to the other large railway companies?

Historically always high density commuter rich traffic justifying electric traction.

 

[muddythefish]

Why aren't more lines electrified ? In a nutshell, because governments have not been willing to pay for it and would rather invest in roads.

An earlier post said it would cost about £6bn to electrify the entire network - peanuts really compared to the enormous benefits electric trains would bring.

The govt recently announced a £15bn road building programme so in spite of some investment in rail in recent years you can see where transport priorities continue to lie.

 

[deltic08]

I can put together a business case for electrification of the West Highland Line, but unfortunately it revolves around such old fashioned concepts like caring about the Balance of Trade and so forth.

On the plus side, there are three hydro stations along the line with spare generating capacity.

All single track, except passing loops, so half the installation costs with double the traffic of double track.

Lower than average overbridges per mile. With single track arch bridges track lowering is cheaper than bridge raising to accommodate the pan and wire as the arch is symmetrical with the track.

Better acceleration and hill climbing to reduce journey time would have to be balanced against the cost of improving track to achieve same time reduction.

I think the West Highland Line would have a very good business case for electrification considering Glasgow-Craigendoran is already wired. 75mph Class 86/6s on the sleepers anyone?
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[QUOTE

 

[NotATrainspott]

Even if the West Highland Line were electrified I would doubt the extension to Mallaig would ever be, given that it effectively acts as a preserved tourist railway that happens to be owned by Network Rail. 25kV AC OHLE over the Glenfinnan Viaduct would somewhat ruin the Harry Potter train experience, methinks.

 

[HSTEd]

At which point I would expect the railway to Mallaig to be operated on a fully commercial basis and be dismantled if it can't cover its costs. If it is to held to ransom by the preserved railway crowd let them pay for its operation.

 

[ChiefPlanner]

A lot of the "business cases" are done on "vehicles per hour" - something like say Skipton to Carnforth with a 2 hourly , 2 car set are going to fail the hurdle on the first pass.

 

[muddythefish]

A lot of the "business cases" are done on "vehicles per hour" - something like say Skipton to Carnforth with a 2 hourly , 2 car set are going to fail the hurdle on the first pass.

..... as a standalone service maybe but combined with Leeds - Carlisle trains and S & C freight there is a reasonable amount of traffic Hellifield - Skipton, cutting the overall cost ?

 

[pablo]

Back on track....
Because railways started with steam. Coal was plentiful and cheap in the Land of Uk. We had to keep the miners in business and so we hung onto steam long after others started changing. Then came the period of cheap oil that put off the need to proceed with electrificaltion. Nowadays, oil is an imponderable and electricity generation has diverse sources of fuel. Which gives us a degree of insulation from the vararities of individual factions upsetting our energy supplies. That is if Mr. Putin behaves himself.

 

[HSTEd]

Pretty much every railway in the UK can practically be made busy enough to justify electrification - the levels of suppressed demand are enormous.

 

[tbtc]

There's various historic reasons for the lack of investment in railways - partly because we were the first with railways (and had lots of stupid competition), meaning a poorly designed "network" of lines - instead of building a rationally designed railway, we spent resources propping up unneeded lines and then closing them.

Plus, economic cycles have meant that we didn't have the money to spare for infrastructure upgrades - so we electrified a fair bit in the 1960s, didn't seem to in the 1970s, electrified more in the 1980s, that generally stopped in the 1990s... then the Ladbroke Grove/ Railtrack nonsense around the Millennium meant that Labour seemed reluctant to spend much (or we too busy tidying up the mess - depending on your political persuasion).

We seem to be on the right track now though - a "thousand" miles of electrification in CP5 will improve the business case for future electrifications (e.g. wiring Leeds - Huddersfield - Manchester will improve the case for Leeds - Calder Valley - Manchester, wiring the Calder Valley line will improve the case for electrification through East Lancashire to Preston).

Obviously some lines are going to have weak cases for wiring (those with fewer than one train per hour being a benchmark), but we've recently built 39x 172s that should last into the 2040s, so there's going to be sufficient DMUs to run a fair few rural routes.

Idea for a separate topic - how many routes could we leave unelectrified in the hands of 172s for another thirty years? (e.g. the Heart Of Wales only requires two DMUs a day at the moment, half a dozen for the Far North/Kyle beyond Dingwall, a couple for Leeds - Morecambe, one or two for Blaenau Ffestiniog, one or two for Stranraer., a couple for the Cornish branches with the worst business cases, a couple for Whitby.. you could probably run thousands of miles of rural routes with the current number of 172s until almost the 2050s... by which time technology will probably be unrecognisable to that of today - "bi mode" may be as standard as "Super Low Floor" buses are today)