Deleted
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Post by Deleted on Aug 6, 2009 9:55:55 GMT
Hi all. While enjoying the delights of the 38 TS heritage run to Stratford yesterday I noticed that there appears to be some alluminium conductor rail in place near the Stratford end by the depot. Is this an experiment and, if so, when did it begin?
The reason I ask is that similar stuff was tried on the single line between Fareham and Botley in Hampshire when that line was electrified in 1990. It consisted of alluminium rail with a steel strip along the top to provide a durable contact surface for the trains pick-up shoes. The reason it was used was that alluminium is a better conductor of electricity than steel and by using it for this section they could a) reduce the requirement for a sub-station thus saving money and, b) evaluate the usefulness of the material for future projects and maybe further savings in subsequent projects.
The value of alluminium at the time was such that the rail had to be put in place on the night that it was delivered to the site as it was in 60' sections which, apparently, two people could walk away with! It was secured to the insulated 'pots' by clips.
It's use on this stretch of line was a b-i-g mistake! It has now been replaced with conventional steel conductor rail after the alluminium rail had to be replaced at least three times over the entire length of the line thus negating any saving. The steel strip along the top had a habit of becoming detached and peeling off like a sardine tin. The design simply was not up the wear and tear of everyday use by main line trains. I dread to think of the effect that an intense LT service will have on it!
I hope that, whoever made the apparent decision to use alluminium conductor rail on LT consulted Network Rail first......
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metman
Global Moderator
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Post by metman on Aug 6, 2009 10:02:38 GMT
Aluminium rail is becoming widespread on LU now. Off the top of my head I've seen it used at Baker Street (Junction), Finchley Road (Jub down), Watford South Junction and on the JLE!
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Post by Dstock7080 on Aug 6, 2009 11:16:56 GMT
District: Gloucester Road, Tower Hill.
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Deleted
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Post by Deleted on Aug 6, 2009 19:13:10 GMT
District: Gloucester Road, Tower Hill. I can't say I've noticed any between tosse points  |
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Post by andypurk on Aug 6, 2009 19:29:37 GMT
All the bits of the rebuilt East London Line that I've seen have also had Aluminium conductor rail too.
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Deleted
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Post by Deleted on Aug 6, 2009 20:18:52 GMT
Aluminium is a non ferrous (no iron content) material where as steel is ferrous. It's always been a problem getting non ferrous material to bond to ferrous material because of the extremely low melt points of non ferrous material against ferrous. By the time the ferrous material melts your non ferrous material has gone all over the place and oxidised.
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Post by Dstock7080 on Aug 6, 2009 21:50:41 GMT
District: Gloucester Road, Tower Hill. I can't say I've noticed any between those points The approaches to Gloucester Road EB (over diamond etc) and the new pointwork west of Tower Hill all have the new smaller aluminium rails. |
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mrfs42
71E25683904T 172E6538094T
Big Hair Day
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Post by mrfs42 on Aug 6, 2009 22:01:23 GMT
One thing that hasn't been mentioned thus far is that the capping is not contiguous with the rail, it is rolled round it in a ∩ shape with a lip to grip the body of the rail; obviating delamination (hopefully!) ;D.
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Post by suncloud on Aug 7, 2009 8:49:41 GMT
I think all the SSL will see ally rail over the coming years in the run up to S-Stock introduction. Efforts are clearly focussed on Met lines at the moment, but I'm sure any works where replacement of current rails are required, especially on the district, will be done in Aluminium.
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North End
Beneath Newington Causeway
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Post by North End on Aug 7, 2009 10:39:26 GMT
I think all the SSL will see ally rail over the coming years in the run up to S-Stock introduction. Efforts are clearly focussed on Met lines at the moment, but I'm sure any works where replacement of current rails are required, especially on the district, will be done in Aluminium. There is a programme to replace the whole of the Sub Surface Lines, up until 2015 I believe. |
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Post by Dstock7080 on Aug 7, 2009 12:33:34 GMT
I think all the SSL will see ally rail over the coming years in the run up to S-Stock introduction. Efforts are clearly focussed on Met lines at the moment, but I'm sure any works where replacement of current rails are required, especially on the district, will be done in Aluminium. I had thought with all the track replacement work going on between Bromley and Upminster that the opportunity would be taken to change the current rails but the old stuff just gets rolled back in. |
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Post by max on Aug 7, 2009 14:57:00 GMT
I remember reading in Modern Railways magazine (I think) a while back that the savings in using aluminium conductor rail made the Mersey Electrics extension to Chester possible. Any problems there?
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Post by Deleted on Aug 7, 2009 23:01:36 GMT
Don't know about Merseyrail. I do know that the stuff that was used twixt Fareham and Botley had the wrap-round spec that Mrfs42 describes above and it didn't help. It may be better for sub-surface lines as I would imagine that the natural wear and tear due to temperature variation affecting the relationship between the metals used would not be such an issue as above ground. Either way, I have a feeling that LT will 'catch a cold' with the stuff in the same way that British Rail/Railtrack/Network Rail did.
The other benefit of using purely steel rail is that it lasts forever! The old stuff was rolled back in between Bromley and Upminster because it was probably good for another few decades. There are many sections of third rail on Southern Region lines that pre-date the Second World War and some may even date from the first L&SWR electification schemes from 1915! The old stuff can be recognised as it is of a much shallower section than modern rail and is jointed with fishplates that only have one bolt either side. Certainly, some exists on the approaches to Waterloo and most lines that were done prior to 1939 still have it. The up and down slow lines between Brookwood and what was Sturt Lane Junction are a prime example and these would have been laid in 1937. I know that modern budgets only think about the short-term savings and benefits of using alluminium but, long term, will it still be there for decades?
P.S Dear Admin. Sorry about starting this thread in the wrong section. SFB syndrome strikes again......
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Post by singaporesam on Aug 9, 2009 9:09:09 GMT
All of the bottom contact rail we have here in Singapore is Aluminium with a Stainless wear surface. We have a fairly constant 35-40 degree C tunnel temperature and get no issues with seperation.
Good to see that someone in LUL is finally doing something about conductor rails without prompting. Ropey negative conductor rail at Richmond was the root cause of the derailment at the North London Line junction a few years ago.
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Ben
fotopic... whats that?
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Post by Ben on Aug 9, 2009 9:43:06 GMT
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Deleted
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Post by Deleted on Aug 9, 2009 21:27:32 GMT
Interesting isn't the word! ThanKs for that. Manna from heaven to a modeller. Love the tantalising glimpse of a 58 trailer too.
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Post by richard1959 on Oct 17, 2009 21:26:51 GMT
BR used aluminum con rail many years ago on what is referred to as High Current Railway, parts of the former W'loo / Channel Tunnel route.
Aluminum has a big advantage over steel rail in so much it has a lower electrical resistance when you consider that power loss in a conductor is I2R that is (current time current time resistance) this also help with volt drop due to the resistance.
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Deleted
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Post by Deleted on Oct 18, 2009 6:19:02 GMT
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Post by geebeezed on Oct 18, 2009 8:23:42 GMT
The main drawback with the ally Juice rail is that it melts quite spectacularly then theres a short of some sort... Hence most, if not all of it's gone off N.R metals by now, including the above mentioned Fareham-Eastleigh section (which we delivered the new Steel replacement last for... A nice warm night, with -6ยบ showing on the Van thermometer!) I've always wondered if PVC plastic with a bonded in Contact strip might work <nips off to the Shed>  |
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