My suggestion to remove third rail as a priority

[HSTEd]

Priority replacement will soak up wiring teams that could be used to make that fully electrified railway a reality.

 

[BestWestern]

I think that replacing the existing network of 3rd rail (bar Merseyrail deep-level, as the tunnels will be nigh on impossible to electrify for any forseeable benefit) should be a priority, as further wiring of the network is due to take place in the near future. If we have a theoretically fully electrified network (with Southern Region on DC), the costs will be astronomical. All OHLE-slightly less astronomical. Besides, what's the point of all this expensive dual-voltage stock (375s, 376s, 450s, 458s, 444s) if we don't allow them to make use of their capabilities?

Speaking from regular SWT travel, I'm very sure that 110mph running could be achieved with the 450s and 444s if the network was wired around the mainline. There are plenty of straight sections, so should be relatively easy to reach 110. And Southeastern's 375/6 fleet has pantographs they never even USE. We should definitely give them somewhere to run under the wires.

Could you explain your statement that a fully electrified network with south eastern DC would be 'astronomically' expensive?! Why would it cost any more than it would do with everything wired? The infrastructure is already there and does a generally good job. The cost of ripping it all up and replacing it with OLE, and then spending millions on converting hundreds of DC only trains, is where "astronomical" would come in. As for dual voltage units, with the standardised construction methods used now and the high starting costs of new stock, it really isn't a massive deal to have trains built in a way which allows easy modification from DC to AC, or eventual removal of one system at a later date.

The third rail kit has provided a perfectly decent system on one of the world's busiest areas of railway for generations. Eventially, at some point in the future, it will probably be replaced. However, common sense suggest that there is no need for this to be any sort of 'priority' against the numerous other rail projects which could and should be considered over the next few years, particularly when there are large swathes of the country which have no electrification at all. Building dual voltage electric units is far less daft than building the next generation of intercity trains as 'bi-mode' because the shiny new GWML wiring is half a job being done on the cheap!

 

[SpacePhoenix]

http://www.railjournal.com/index.ph...ion-choices-overhead-ac-vs-third-rail-dc.html

Seems like that article explains the pros and cons of each

 

[anme]

Also, if line restriction is 100 or below and it's electric trains running what's the point of paying for expensive overhead wires?
Another thing, where's the money?

The point is that AC overhead wires are CHEAPER. Read this thread from the start and you will learn why.
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Could you explain your statement that a fully electrified network with south eastern DC would be 'astronomically' expensive?! Why would it cost any more than it would do with everything wired? The infrastructure is already there and does a generally good job. The cost of ripping it all up and replacing it with OLE, and then spending millions on converting hundreds of DC only trains, is where "astronomical" would come in.

The idea is that third rail would be replaced as it became life expired (some of it is very old). It has to be replaced one way or the other, so why not upgrade it to something better and save money at the same time?

If this goes ahead, I expect it will take at least 50 years, as that's the approximate lifetime of third rail infrastructure.

 

[ac6000cw]

I think it is Switzerland that has 100% OHLE and I also think most people would say Switzerland is one of the most beautiful countries on earth. IIRC

It does (and it is v.beautiful ) - the entire Swiss railway system is electrified, but that was originally driven by a mixture of the terrain causing problems with operating steam traction in long tunnels (and over long steep gradients), and the availability of very cheap hydro-electric power.

As for top-contact 3rd rail - with hindsight 80 years later, post-grouping the Southern Railway probably took the correct decision, based on the available traction technology of the 1920's, to continue to electrify their suburban network as 3rd rail (and convert the 6.6 kV/25Hz OHLE system of the ex-LBSCR lines to it). It made the traction equipment on the trains cheap, simple and reliable - important for a high-density train service (and the SR was never a railway to waste money - they recycled hauled stock into EMU's, and made signal posts out of old rails, for example).

The big mistake (IMHO) was using 3rd rail when they (and later BR) extended electrification out into the 'country' areas (Brighton, Portsmouth, Kent coast etc.) - 1500V DC overhead would have been more sensible, and would have allowed fairly simple dual-system EMU's (e.g. traction motor pairs connected in parallel for 750V or in series for 1500V). Sure, you need to raise bridges etc. to get more vertical clearance, but there are fewer of those outside urban areas anyway in relation to route miles.

3rd rail makes sense for 'metro' systems (albeit modern systems normally use bottom contact rails for safety and ice protection), but not for mainline railways.

 

[HSTEd]

The point is that AC overhead wires are CHEAPER. Read this thread from the start and you will learn why.

It is cheaper if the third rail equipment it replaces is about to be junked anyway.

People are suggesting ripping all the third rail up right now, which would obviously be astronomical compared to a rolling replacement.

And it would be fun to see how they plan on rigging eight track gantries in the Waterloo approach.

 

[anme]

Priority replacement will soak up wiring teams that could be used to make that fully electrified railway a reality.

We could always train up some more (instead of teaching them third rail renewal). This is going to be a long job!

That said, I'm not promoting priority replacement of third rail (i.e. before the equipment is life expired). There might be a case for it in some places, e.g. to increase capacity through better acceleration, long term cost savings or because the rest of the line is being converted, but I don't have the knowledge to make a judgement on that right now.

 

[HSTEd]

We could always train up some more (instead of teaching them third rail renewal). This is going to be a long job!

I propose this occasionally but everyone seems to think we should instead plan the job to obtain Xeno's paradox as the result. Stretching the task out for as long as possible.

 

[59CosG95]

It is cheaper if the third rail equipment it replaces is about to be junked anyway.

People are suggesting ripping all the third rail up right now, which would obviously be astronomical compared to a rolling replacement.

And it would be fun to see how they plan on rigging eight track gantries in the Waterloo approach.

I wasn't saying start today with the SR re-electrification; more as a CP6/7 project after the Electric spine is finished. On the Waterloo note: they've done it with Gare du Nord, Munich Hauptbahnhof, Roma Termini, Madrid Atocha, and loads of European stations; no reason for us not to be able to wire Waterloo up.

 

[snowball]

I propose this occasionally but everyone seems to think we should instead plan the job to obtain Xeno's paradox as the result. Stretching the task out for as long as possible.

I think they're saying that it should be done in a prudent and economic manner, rather than a boom-and-bust manner.

 

[edwin_m]

The big mistake (IMHO) was using 3rd rail when they (and later BR) extended electrification out into the 'country' areas (Brighton, Portsmouth, Kent coast etc.) - 1500V DC overhead would have been more sensible, and would have allowed fairly simple dual-system EMU's (e.g. traction motor pairs connected in parallel for 750V or in series for 1500V). Sure, you need to raise bridges etc. to get more vertical clearance, but there are fewer of those outside urban areas anyway in relation to route miles.

I actually think we should be heartily glad that the SR didn't go to 1500V - it would have resulted in yet another non-standard electrification system, widespread compared to the self-contained routes on the GE and Woodhead where it was actually used. However, with hindsight, it would have been better if they'd gone for 25kV (or 6.25kV) for extensions done after the mid-50s when that system was standardised on the rest of the network. It would have been relatively easy to equip the new fleets with pantograph/transformer cars feeding the existing DC equipment, as was retrofitted to the GE 1500V units.

 

[Class172]

I wasn't saying start today with the SR re-electrification; more as a CP6/7 project after the Electric spine is finished. On the Waterloo note: they've done it with Gare du Nord, Munich Hauptbahnhof, Roma Termini, Madrid Atocha, and loads of European stations; no reason for us not to be able to wire Waterloo up.

As others have said previously, I don't understand the need to replace 3rd rail that otherwise works fine. At least the lines are electrified - there are many other lines that deserve to gain electrification. It's similar to a vicious cycle, where the SE will constantly get all the money thrown at it, at the expense of everywhere else.

A strategic rolling replacement would be far more beneficial, as and when the 3rd rail becomes life-expired, allowing electrification/improvements to still be carried out across the country. The phrase "If it ain't broke, don't fix it" comes to mind.

 

[aylesbury2]

So what are you going to do with the entire Tube network then? Go back to 19th century coal-fired locomotives? xD

 

[Manchester77]

So what are you going to do with the entire Tube network then? Go back to 19th century coal-fired locomotives? xD

It's less of an issue on LU since trains don't run a 90/100mph and on one line you won't have consecutive 12 car EMUs in a row. LU can also be fitted with platform edge doors whereas you couldn't really do that at Waterloo for example where you have a 450 using a platform and then a 444 and then a 455.

 

[3141]

The big mistake (IMHO) was using 3rd rail when they (and later BR) extended electrification out into the 'country' areas (Brighton, Portsmouth, Kent coast etc.).

I think I recall, at the time of the Southampton and Bournemouth electrification in 1967, an article about the project in which someone from BR said they had looked at 25 KV AC, though partly to confirm that it wasn't practicable.

As we look back at those schemes from our position much later, we may think they should not have done them with 750V DC, but there were powerful reasons at the time for doing it the way they did. Money was tight, for the Southern Railway in the 1930s and for BR in the fifties and sixties. Using the same system as the one already in use on the network provided inter-operability and flexibility. Speeds and acceleration didn't have to be what we would like them to be today, but electrification did provide a big improvement over the steam services it replaced.

There may be more of a case for criticising BR over the Bournemouth electrification, when overhead AC schemes were going on in other parts of the country, but the network flexibility argument was a very strong one.

 

[edwin_m]

http://www.railjournal.com/index.ph...ion-choices-overhead-ac-vs-third-rail-dc.html

Seems like that article explains the pros and cons of each

I'd take that with a rather large pinch of salt. It seems to be concentrating on metro routes, whereas we are thinking main line where some of the critical factors are a bit different. There are also some rather unexpected and unsubstantiated statements including that third rail eliminates EMC problems and that the type of traction system in itself defines the maximum number of passengers per hour.

 

[anme]

As others have said previously, I don't understand the need to replace 3rd rail that otherwise works fine. At least the lines are electrified - there are many other lines that deserve to gain electrification. It's similar to a vicious cycle, where the SE will constantly get all the money thrown at it, at the expense of everywhere else.

A strategic rolling replacement would be far more beneficial, as and when the 3rd rail becomes life-expired, allowing electrification/improvements to still be carried out across the country. The phrase "If it ain't broke, don't fix it" comes to mind.

Strategic rolling replacement is what's being considered, except perhaps by the more excitable members of this forum. I wouldn't totally rule out replacement of third rail before it's life expired in all cases, but it would need very good justification.

 

[SpacePhoenix]

Strategic rolling replacement is what's being considered, except perhaps by the more excitable members of this forum. I wouldn't totally rule out replacement of third rail before it's life expired in all cases, but it would need very good justification.

I think there's been a few times recently where there's been trouble with the 3rd rail on the Waterloo-Weymouth line south of Southampton, so is the 3rd rail south of Southampton reaching the point of being life expired?

 

[hassaanhc]

I think there's been a few times recently where there's been trouble with the 3rd rail on the Waterloo-Weymouth line south of Southampton, so is the 3rd rail south of Southampton reaching the point of being life expired?

There was actually an issue between Bournemouth and Weymouth yesterday where a single 444 or 450 unit would get gapped, so all services had to run in multiple with delays/alterations waiting for trains to arrive and attach.

 

[HSTEd]

I think they're saying that it should be done in a prudent and economic manner, rather than a boom-and-bust manner.

Does it really matter if its boom-and-bust if it occurs after the entire network has been electrified?
The equipment for electrifying railway lines that are in use is rather different from that for doing so on new construction.

 

[SpacePhoenix]

There was actually an issue between Bournemouth and Weymouth yesterday where a single 444 or 450 unit would get gapped, so all services had to run in multiple with delays/alterations waiting for trains to arrive and attach.

What location on that section of line was the problem at?

 

[59CosG95]

Anyone know which sections are closest to life expiry? Farnham's looked pretty bad-corrosion had eaten away through the rails so much you could see the track on the other side through them. Of course, Basingstoke-Southampton (possibly beyond) will be the pilot scheme for all this.

 

[edwin_m]

I would guess the condition of the substations and other equipment is far more important when deciding on replacement than that of the third rail itself, which can be swapped quite easily if necessary.

 

[hassaanhc]

What location on that section of line was the problem at?

Between Wareham and Wool http://www.realtimetrains.co.uk/train/W11437/2014/05/31/advanced

 

[rdlover777]

hi, would the rail network in the south of England (southern and southeastern's lines) be converted to overhead from 3rd in the near future?

 

[61653 HTAFC]

hi, would the rail network in the south of England (southern and southeastern's lines) be converted to overhead from 3rd in the near future?

The short answer is 'No'. The longer answer is that it is currently planned to convert Basingstoke-Southampton to 25kVAC overhead as part of the 'Electric Spine' project for freight. The majority of electric trainsets currently using this route can be converted to dual-voltage fairly easily. I think that NR plan to use this as a 'test-bed' project to decide whether to progressively convert the entire DC network, though this would likely be done as and when the DC equipment (both infrastructure and trains in the case of lines closer to London) is up for renewal.

 

[snowball]

hi, would the rail network in the south of England (southern and southeastern's lines) be converted to overhead from 3rd in the near future?

It has been seriously looked at and will probably happen over a few decades as old 3rd rail equipment needs to be replaced.

 

[SpacePhoenix]

I think I remember reading somewhere that the 3rd rail electrification south of Bournemouth was done on the cheap so that section of 3rd rail might have a shorter working life. Hopefully the overhead when installed on the spine will at least go as far south as Poole, would be nice if it went all the way to Weymouth.

Once the routes between Kent and London get converted to overhead it would also give Eurostar a few diversionary routes for emergencies

 

[AM9]

I think I remember reading somewhere that the 3rd rail electrification south of Bournemouth was done on the cheap so that section of 3rd rail might have a shorter working life. Hopefully the overhead when installed on the spine will at least go as far south as Poole, would be nice if it went all the way to Weymouth.

Once the routes between Kent and London get converted to overhead it would also give Eurostar a few diversionary routes for emergencies

The 374s and any subsequent CTRL stock just wouldn't fit the gauge unless the NR routes were enlarged to GB+. In theory, the 373s could use them but I would imagine a plethora of commercial and legal obstacles would prevail.

 

[apk55]

http://www.railjournal.com/index.ph...ion-choices-overhead-ac-vs-third-rail-dc.html

Seems like that article explains the pros and cons of each

This article looks at each application in isolation, not a network with a variety of different services often sharing tracks. We need a common system that can supply everything from high speed passenger trains or heavy freight trains to light branch line services. Even with 1k5 DC electrification we could not run our main line pasenger services at present speeds and 3KV would be at the limit. Therefore 25kV AC is the best choice. There are many cases where it could be cheaper to use a different system, but unless it is an isolated network with sufficient traffic to have a dedicated fleet (such as a tramway network) then econmies of scale and shared tracks apply.