Proliferation of shiny new conductor rails

[Deleted]

How far have they spread?

Wood Lane area.
Croxley junction area.
Some other areas surely.

Will we see them on the parts of the SSR that are shared with the Pic?

[Colin]

District (all to be read as partially between):

Dagenham Heathway & Becontree westbound
Upney & Barking westbound
Barking & East Ham both
Earls Court & Gloucester Road eastbound
West Brompton & Putney Bridge

[v52gc]

Most of the Uxbridge branch AFAIK

[citysig]

They will eventually be everywhere. As part of the power upgrades on the SSR (in relation to the new stock) this aluminium rail (or low-loss rail as it's known - for reasons surrounding all things electrical and technical) will be installed throughout.

On the Met there will be additional sub-stations installed to supply the network - one of which is due to be commissioned any day now between Finchley Road and Baker Street.

[metman]

at Marlborough Road....

Will the new conductor rails perform well in the snow however?

[DWS]

Aug 18, 2011 16:57:52 GMT @citysig said:

They will eventually be everywhere. As part of the power upgrades on the SSR (in relation to the new stock) this aluminium rail (or low-loss rail as it's known - for reasons surrounding all things electrical and technical) will be installed throughout.

On the Met there will be additional sub-stations installed to supply the network - one of which is due to be commissioned any day now between Finchley Road and Baker Street.

What other new sub-stations will be installed ?

[citysig]

Yes Marlborough Road.

I'm almost certain we had low-loss in use last winter. I'm sure the Croxley area (which if I remember was one of the first areas) had it installed over a year or more ago - with other areas gaining it around the same time or just after.

I don't know if any substantial differences were found between ice on low-loss or on the original rails.

[citysig]

Aug 18, 2011 17:06:04 GMT DWS said:

What other new sub-stations will be installed ?

The only other one on the Met/Circle (north side) that I know of is in the Farringdon area. There was talk of providing the Hammersmith branch with another, but this appears to have died a death.

There will presumably be other upgrades on the District side to enable the S-stock to operate fully.

[Deleted]

Are these new rails being installed because the old ones are worn out or merely for policy reasons? The aluminium rails will clearly have benefits of having reduced losses and being lighter to handle but they will be more expensive to make and will wear out faster. And since they dissipate less heat they will be more prone to icing in winter. I suspect that the overall economic argument is far from simple.

[castlebar]

Are these new rails being installed because the old ones are worn out or merely for policy reasons?

Yes, Cameron likes a nice shiny new things

[Ben]

From what I understand they are extremely expensive, so heres hoping they are found to be more beneficial than originally hoped!

[DWS]

Aug 18, 2011 18:56:29 GMT @ohmslaw said:

Are these new rails being installed because the old ones are worn out or merely for policy reasons? The aluminium rails will clearly have benefits of having reduced losses and being lighter to handle but they will be more expensive to make and will wear out faster. And since they dissipate less heat they will be more prone to icing in winter. I suspect that the overall economic argument is far from simple.

The aluminium current rails have a stainless steel top, the Jubilee Line extension have had this type of rail since it opened in 1999, as far as I know there has been no need to replace it due to wear.

[Deleted]

A stainless steel top? That certainly fixes the wear issue but it also confirms Ben's statement; these rails will be hugely expensive. This, in turn, opens up another possibly contentious debate; why not delete the centre rail, move the shoes on all the trains, buffer the signalling if necessary and convert to three rail?

[Deleted]

That would be taking the mick in the heritage department

I think these rails look good and by the sounds of things they are a massive improvement over the older ones. If the ones on the JLE have not been replaced since 1999 that is very good. A good investment by LU here.

[Ben]

1999 is only 12 years back. Thought current rails supposed to do about 30-odd years if on a mainline? And, as if often noted, on sidings and occaisional use lines, they can be much older; the old CLR inverted 'U' conductor rails were still in evidence at White City Depot until it was demolished.

[DWS]

The new type of conductor rails are made by Brecknell Willis, look on their website for more information.

[metman]

who also make pantographs......

[Deleted]

and shoegear.....

[Deleted]

Right, this is my understanding of it.

What is it?

It's called Extra Low Loss Conductor Rail (or ELLCR for those of us that love an acronym). It is aluminium with a 5mm steel cap and comes in sections of about 15m which you bolt together. It reaches the end of it's life when the cap wears out so the resistance doesn't change over its life. It has a resistance of about 8 milliohms per loop km compared to about 30 for your average steel one (off the top of my head there I'm afraid, I could have made a mistake with the numbers. However, it's about that magnitude)

Is this type of conductor rail more expensive than steel?

Marginally so but it is easier to install (much lighter) so the overall installation costs if you were doing total track replacement are pretty similar.

Is it being put in to replace life expired con rail or is it policy?

Neither. It goes in where the voltage between substations would become unacceptably low. Obviously, new trains and signalling combined allow for larger current draws by trains as performance improves (and you can get more trains on the line) and this can cause voltage problems when you are a bit of a distance away from a substation. It is not currently LU policy to routinely change over old steel for new ELLCR.

Does it wear out quicker?

No. If anything it lasts longer. The stuff on the Jubilee (which is LLCR rather than ELLCR) looks like it will last over 100 years based on a 2004 report. Some of it had been in service for 10 years at that point and most 5. It's not going to wear out in 30.

So there must be a catch?

It's not all good. You need to replace all the pots with plastic ones (this isn't all bad, as far as I know, they don't cause earth faults like porcelain ones) which makes the like-for-like replacement a bit more of a pain/expense. Also, particularly round ramps, it has worn out so they've developed an all stainless steel ramp. There might be a case for retaining some old steel type in high wear areas.

What do maintenance think?

Well, you can't be as rough with it, but since it doesn't really wear down, you don't have to keep putting shims under it to keep it at the right hight. In general, it's a win here too.

What about the mainline?

They had a go about 20 years ago but the cap fell off so they don't like it. Looks like they are changing their mind now (incidentally, as far as I know, it's not happened to us - tech is more mature now I guess).

Anything else?

Obviously it reduces losses in the con rails (which helps the voltage - the reason why it's going in) so it's good for not making the tunnels any hotter. It not the solution to that issue, but it's probably part of it.


Hope that answers a few questions and clears up a couple of misunderstandings.

[dmncf]

This post referred to the new substation under construction adjacent to Edgware Road D&C Station. A lot of work is being done to construct new retaining walls as part of the substation.
districtdave.proboards.com/index.cgi?board=ssr&action=display&thread=16374

Aug 18, 2011 17:12:48 GMT @citysig said:

Aug 18, 2011 17:06:04 GMT DWS said:

What other new sub-stations will be installed ?

The only other one on the Met/Circle (north side) that I know of is in the Farringdon area. There was talk of providing the Hammersmith branch with another, but this appears to have died a death.

There will presumably be other upgrades on the District side to enable the S-stock to operate fully.

[Deleted]

This conductor rail was first marketed through Brecknell Willis, the pantograph people, but they also make all sorts of bits and pieces relating to conductor rails, and current collection. Check out their website with some nice piccies of the JLE, and other exciting installations.

Go through their list of stuff and there are several sections on both the rail, which is manufactured at their factory at Chard, and shoe gear for top, side, and underside contact. I am not aware of any other manufacturer of the Aluminum / Stainless composite rail in the UK. Steel rail is now coming from one of the other Corus Tata plants, Workington having closed.

Yes it is more expensive, but less resistance = less power losses so more juice at the railhead = more power for more trains. (The cross section of the DLR third rail is very small.) And I think it copes with regeneration better, but I'm rusty on the techie stuff, I've only got steel rails! I'd better have a longer look at their web-site.

PS I drafted this earlier, meanwhile jackofall has posted a more comprehensive comment than mine, but we are both on the same track ..... Big Brother intervened (groan .... Ed)

[Deleted]

Jackofall, thanks for your input, it’s very illuminating; the entire activity now makes much more sense. Indeed, if you look at the composite construction of this rail (on the Brecknell Willis website) it’s quite state of the art. Its reduced weight (apparently a third of the weight of the steel rail) plus the elimination of welding must considerably reduce the installation costs and the elimination of shimming must similarly simplify maintenance. However, I suspect that the key fact for LU is the improved performance under high current conditions without which the proposed future timetable (post new signalling) would not be viable.

[Deleted]

Just for entertainment value Channel 5 had its largest audience EVER with BigBro! Its like Marmite, love it or loathe it. But after the Hon MP for Bridge 19 and a short section of the ELLX played pussy cat with Rula Lenska, this years controversy is Sally Bercow, is she demeaning the Speaker?
Discuss with Kirsty Wark on Newsnight, but all we got on BB tonight was the red-top queen, Kerry Katona, who has nominated Mrs Speaker for eviction ....... I'll refrain from starting a Big Brother Thread ..... (thank gawd for that .... Ed)

[Deleted]

Aug 19, 2011 19:59:53 GMT @jackofall said:

Does it wear out quicker?

No. If anything it lasts longer. The stuff on the Jubilee (which is LLCR rather than ELLCR) looks like it will last over 100 years based on a 2004 report. Some of it had been in service for 10 years at that point and most 5. It's not going to wear out in 30.



What do maintenance think?

Well, you can't be as rough with it, but since it doesn't really wear down, you don't have to keep putting shims under it to keep it at the right hight. In general, it's a win here too.

Surely if it does not wear, it must wear shoegear more quickly, so may be a false economy im that respect if a fleets shoegear life expectancy is reduced.

[Ben]

Not necessarily by a vast amount. All depends on the hardness of a material. If you rubbed two bits of granite together with the same force applied as when rubbing two bits of rubber, or sandstone, or pine, the granite would still last far longer.

A quick search gives Steels value on Mohs scale as 4-5.5, and stainless as 5.5-6.3 (VPN values would be more indicative...), so the shoegear will sustain greater wear, and as you suggest wear out more quickly, but I'd hazzard that the loss of durability would be proportionally far less than the gain in durability from the conductor rails. So not necessarily a false economy overall.

[Ben]

By the way, many thanks to Jackofall for the answer. Pretty much sums up everything pertainant!

I'm curious though as to the problems that will occur upon wearing out. No doubt it'll all be prevented, but Aluminium bonded to other metals in a circuit can lead to problems; viz. the problems that aluminium wire experienced in the 70s as an alternative to copper.

[Deleted]

I'm curious though as to the problems that will occur upon wearing out. No doubt it'll all be prevented, but Aluminium bonded to other metals in a circuit can lead to problems; viz. the problems that aluminium wire experienced in the 70s as an alternative to copper.

Ah, the dreaded purple plague as it was referred to in early integrated circuit design.

This is a very valid point particularly as the stainless steel layer started to separate in earlier trials. Brecknell Willis have published a paper on their website which explains their process (which they have patented). The rails today are clearly different from the original and they are quoting lifetimes which makes one assume they have been thoroughly tested. LU have the added confidence that their train speeds are relatively low but you can bet that NR will be looking over LU's shoulder to witness their experience as part of an assessment of the rail's high speed potential.