101 Posted January 18, 2019 Share Posted January 18, 2019 As far as I know the tunnels have their overhead conductors in place and have had for well over a year. They have a solid rail system rather than wires though. I did hear somewhere that the conductor bar is having to have a good clean before it can be used. Jamie I finished nearly 18 months ago and they were in place for a while before that Link to post Share on other sites More sharing options...
jim.snowdon Posted January 18, 2019 Share Posted January 18, 2019 I had heard rumours that the aluminium conductor beam was none too happy with the damp confines of the Severn tunnel, with corrosion, and electrolytic corrosion between the aluminium and the copper, being a problem. Jim Link to post Share on other sites More sharing options...
RMweb Gold rodent279 Posted January 18, 2019 RMweb Gold Share Posted January 18, 2019 (edited) I had heard rumours that the aluminium conductor beam was none too happy with the damp confines of the Severn tunnel, with corrosion, and electrolytic corrosion between the aluminium and the copper, being a problem. Jim IIRC, the aluminium will plate the copper? Edit:- no, other way round. Edited January 18, 2019 by rodent279 Link to post Share on other sites More sharing options...
RMweb Premium 3rd Rail Exile Posted January 19, 2019 RMweb Premium Share Posted January 19, 2019 (edited) IIRC, the aluminium will plate the copper? Edit:- no, other way round. The copper won't plate the aluminium because the copper won't actually dissolve. However, the presence of the copper will vastly increase the corrosion rate of the aluminium in a damp (presumably salty atmosphere) to the point where it will be useless as a support. If feasible, an aluminium wire would be preferable, but I don't know what this would do to the wear rate of contact strips etc... Edit: Or alternatively ensure that the copper contact wire is not in direct contact with the aluminium support (plastic coat the aluminium or something similar) Edited January 19, 2019 by 3rd Rail Exile Link to post Share on other sites More sharing options...
NIK Posted January 19, 2019 Share Posted January 19, 2019 The copper won't plate the aluminium because the copper won't actually dissolve. However, the presence of the copper will vastly increase the corrosion rate of the aluminium in a damp (presumably salty atmosphere) to the point where it will be useless as a support. If feasible, an aluminium wire would be preferable, but I don't know what this would do to the wear rate of contact strips etc... Edit: Or alternatively ensure that the copper contact wire is not in direct contact with the aluminium support (plastic coat the aluminium or something similar) Hi, How do we know the groove in the aluminium where the copper sits hasn't been give a conductive coating such as electrically conductive anodising?. The rest of the aluminium (alloy?) surface has presumably been given a surface treatment?. Regards Nick Link to post Share on other sites More sharing options...
RMweb Premium 3rd Rail Exile Posted January 19, 2019 RMweb Premium Share Posted January 19, 2019 Hi, How do we know the groove in the aluminium where the copper sits hasn't been give a conductive coating such as electrically conductive anodising?. The rest of the aluminium (alloy?) surface has presumably been given a surface treatment?. Regards Nick Unless someone on here can provide the technical details, we don't... I'm simply saying that any electrical conductivity between the copper contact wire and the aluminium (which as you say is almost certainly an alloy of some description) support would be a seriously bad thing... Link to post Share on other sites More sharing options...
RMweb Premium 3rd Rail Exile Posted January 19, 2019 RMweb Premium Share Posted January 19, 2019 Unless someone on here can provide the technical details, we don't... I'm simply saying that any electrical conductivity between the copper contact wire and the aluminium (which as you say is almost certainly an alloy of some description) support would be a seriously bad thing... Having a read of the links provided by Fat Controller yesterday is interesting. On the manufacturer's website there is a link to an RCOS Statement on Corrosion, which explains how they try to avoid bimetallic corrosion and how some of our ancient civil engineering manages to overcome those precautions... https://www.furrerfrey.ch/dam/jcr:2116c345-4099-4194-bec9-0d1e4bc6c4f2/181025_rdn%20ROCS%20corrosion%20statement.pdf Link to post Share on other sites More sharing options...
Titan Posted January 19, 2019 Share Posted January 19, 2019 (edited) Unless someone on here can provide the technical details, we don't... I'm simply saying that any electrical conductivity between the copper contact wire and the aluminium (which as you say is almost certainly an alloy of some description) support would be a seriously bad thing... It has been given a coating, a special grease, as mentioned in the PDF linked to above. I don't think it has worked too well as the stuff fitted in the Severn tunnel has corroded to the point of collapse already and it has not even been switched on yet, which is what led to the suspension of product acceptance. Edited January 19, 2019 by Titan Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted January 19, 2019 RMweb Gold Share Posted January 19, 2019 First time I've seen a shot from Patchway with the OHL in place - that looks a LOT less obtrusive than what is in place in the Thames Valley and from Didcot to Swindon The situation varies. On the quadruple track sections there are mainly, but not exclusively, portal structures over all four running lines and the width of station platforms as well - the depth of portal girder does however vary and Didcot is by far the worst example. The height of the masts also varies although most single line masts further west appear to be shorter (and some are very short such as in the AONB near Patchway) which changes the vertical impression considerably. Also of course the section of the single line masts is considerably less than that of the masts carrying portals - for obvious reasons. Overall the appearance of the overhead is massively simpler than anywhere else on the NR network (apart from tramway style overhead such as at Paddington station) because attaching the contact and catenary wires involves only one registration arm,. it is interesting to compare that simplicity with the overhead knitting which is now 'gracing' the approach to the. Crossrail tunnels in the vicinity of Subway junction where there is a multiplicity of components and fixing points between the supporting structure and the two arms carrying - separately - the contact and catenary wires. Overall I think it depends very much what you compare with what - many of the GWML quadruple track supporting portals look 'heavy' because of the size/height of the masts, and in some cases (e.g. Didcot) because of the depth of the portal beams, which are as it happens not dissimilar from those in the approaches to Paddington which have been there over 20 years. But equally the means of attaching and supporting the contact and catenary wirs is much simpler involving fewer components. Another 'heavy' feature is the portal beams used to hold the tensioning units but these in any case use more substantial masts on the single line wired sections. Oddly amongst all the moaning there seems to have been little mention of several types of structure structures which, even at a bit more than a passing glance, are little different from those in use elsewhere on the network over the past 50 years or more - perhaps that's because there aren't so many of them or maybe because they aren't contentious? I travelled over the London end of the GNML last Saturday from Kings Cross to Stevenage and, like the cat's cradle of of overhead knitting approaching the west portal of the Crossrail tunnel, I was struck by the complexity and number of components needed to attach the business end of the whole thing, i.e. the contact and catenary wires, to the structures. There would seem to be good and bad involved wherever you look at overhead wiring on the national network. 1 Link to post Share on other sites More sharing options...
RMweb Gold rodent279 Posted January 19, 2019 RMweb Gold Share Posted January 19, 2019 The only thing I don't really like is the mixture of sizes and heights, sometimes in close proximity, which gives a haphazard appearance. I'm sure there's a good reason for it though. Link to post Share on other sites More sharing options...
caradoc Posted January 19, 2019 Share Posted January 19, 2019 The OLE structures in the Goring area which caused so much gnashing of teeth do not appear to have been replaced by less obtrusive equipment; Presumably now the fuss has died down any thought of spending yet more money here has been abandoned ? Link to post Share on other sites More sharing options...
RMweb Gold rodent279 Posted January 19, 2019 RMweb Gold Share Posted January 19, 2019 (edited) The OLE structures in the Goring area which caused so much gnashing of teeth do not appear to have been replaced by less obtrusive equipment; Presumably now the fuss has died down any thought of spending yet more money here has been abandoned ?I think they should leave them there, and paint them bright red, just to wind up the nimbys! Edit: maybe they should be painted green, with copper caps. Perhaps that would placate them? Edited January 21, 2019 by rodent279 2 Link to post Share on other sites More sharing options...
Platform 1 Posted January 19, 2019 Share Posted January 19, 2019 And something different again in Patchway Gap: https://twitter.com/NoelDolphin/status/1084861500248997888 Link to post Share on other sites More sharing options...
St. Simon Posted January 19, 2019 Share Posted January 19, 2019 The OLE structures in the Goring area which caused so much gnashing of teeth do not appear to have been replaced by less obtrusive equipment; Presumably now the fuss has died down any thought of spending yet more money here has been abandoned ? Hi, I believe the agreement was that work wasn’t going to start on any redesign until at least the Reading to Didcot area was up and running fully, and there’s still a lot of people working on the extension to Cardiff, so it could be far down the list. Simon 2 Link to post Share on other sites More sharing options...
jim.snowdon Posted January 19, 2019 Share Posted January 19, 2019 Hi, I believe the agreement was that work wasn’t going to start on any redesign until at least the Reading to Didcot area was up and running fully, and there’s still a lot of people working on the extension to Cardiff, so it could be far down the list. Simon Long before anyone gets round to them, the weather will have taken the shine off the galvanising and they will have simply blended ot the background of normality. Even then, to replace them will require contractors, who will be busy elsewhere, and a considerable number of possessions, when something as non-critical as changing perfectly functional structures will be at the bottom of the priority tree when it comes to competing with other jobs that need to be done just to keep the railway running. Jim Link to post Share on other sites More sharing options...
caradoc Posted January 20, 2019 Share Posted January 20, 2019 Long before anyone gets round to them, the weather will have taken the shine off the galvanising and they will have simply blended ot the background of normality. Even then, to replace them will require contractors, who will be busy elsewhere, and a considerable number of possessions, when something as non-critical as changing perfectly functional structures will be at the bottom of the priority tree when it comes to competing with other jobs that need to be done just to keep the railway running. Jim Absolutely, and surely completing the missing electrification (ie to Oxford and Bristol Temple Meads) must be a far higher priority than an expensive and extremely disruptive process of replacing almost brand new equipment because a few people don't like its appearance ? Link to post Share on other sites More sharing options...
RMweb Premium jamie92208 Posted January 20, 2019 RMweb Premium Share Posted January 20, 2019 (edited) Absolutely, and surely completing the missing electrification (ie to Oxford and Bristol Temple Meads) must be a far higher priority than an expensive and extremely disruptive process of replacing almost brand new equipment because a few people don't like its appearance ? It would be interesting to track how house prices in Goring have moved and whether the "appalling things" have actually had any effect. I must stress that I have no sympathy for the objectors at all. Jamie Edited January 20, 2019 by jamie92208 Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted January 20, 2019 RMweb Gold Share Posted January 20, 2019 Long before anyone gets round to them, the weather will have taken the shine off the galvanising and they will have simply blended ot the background of normality. Even then, to replace them will require contractors, who will be busy elsewhere, and a considerable number of possessions, when something as non-critical as changing perfectly functional structures will be at the bottom of the priority tree when it comes to competing with other jobs that need to be done just to keep the railway running. Jim It already has Jim - after all it's had several years of weathering. The other thing is that NR said it would consider a replacement design when the finance was available. Obviously that finance isn't available otherwise the ohle would be well on its way to Temple Meads by now, and it isn't. It would be interesting to track how house prices in Goring have moved and whether the "appalling things" have actually had any effect. I must stress that I have no sympathy for the objectors at all. Jamie There is a hard core of moaners in Goring - so far they've objected to the ohle structures (pyrrhic victory I suspect), the conversion of a closed pub into a Tesco Local (lost), sale of land near the railway for new housing (lost), a hydro electric scheme for the River Thames (umpteen references to various levels of Court although Planning Permission was granted, seems it might not yet be finalised although it has been going on for three years!). House prices in the immediate Goring area seem to have moved very much in concert with the norm for South Oxfordshire and are in some cases higher than similar properties elsewhere in the area. Goring's attractiveness for commuting has no doubt been helped by electrification which has thus had a positive effect on house prices 3 Link to post Share on other sites More sharing options...
caradoc Posted January 20, 2019 Share Posted January 20, 2019 Damn; I was hoping house prices in Goring had collapsed so I could afford to live there ! Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted January 20, 2019 RMweb Gold Share Posted January 20, 2019 Damn; I was hoping house prices in Goring had collapsed so I could afford to live there ! I wouldn't bother - the traffic is very bad through the centre of the village and the cheese shop in Streatley is long gone (although there s one in Pangbourne) 1 Link to post Share on other sites More sharing options...
RMweb Premium corneliuslundie Posted January 21, 2019 RMweb Premium Share Posted January 21, 2019 "the cheese shop in Streatley is long gone" Oh, no point in visiting then. I remember that shop when cycling in the Vale. And if there is as much traffic as is reported it sounds as though it is no longer a pleasant place to cycle. Roye England would be horrified - but probably not very surprised. Jonathan Link to post Share on other sites More sharing options...
Mike Storey Posted January 21, 2019 Share Posted January 21, 2019 I wouldn't bother - the traffic is very bad through the centre of the village and the cheese shop in Streatley is long gone (although there s one in Pangbourne) Did it just have camembert, but it was a bit runny? In fact, it ran out of the shop? Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted January 21, 2019 RMweb Gold Share Posted January 21, 2019 "the cheese shop in Streatley is long gone" Oh, no point in visiting then. I remember that shop when cycling in the Vale. And if there is as much traffic as is reported it sounds as though it is no longer a pleasant place to cycle. Roye England would be horrified - but probably not very surprised. Jonathan I certainly wouldn't recommend cycling through Goring and up the hill into Streatley or vice versa - lots of parked cars on the Streatley side make it a bit like a form of Russian roulette when you're in a car let alone on a cycle and the 'Give Way' markings over the narrow stretch in the centre of Goring seem to be completely misunderstood by some motorists. The cheese shop in Streatley had a very good reputation but as can be seen below it didn't survive for various reasons - https://www.independent.co.uk/arts-entertainment/obituary-major-patrick-rance-1118828.html Link to post Share on other sites More sharing options...
RMweb Gold Joseph_Pestell Posted January 21, 2019 RMweb Gold Share Posted January 21, 2019 Just back from a few weeks in France. The journey back, unusually using le Shuttle, involved a lot of mileage alongside high speed electrified lines, including HS1. I still do not understand why GWML needs such monstrosities of structures to support its OHE when those high-speed lines do not. Link to post Share on other sites More sharing options...
RMweb Premium jamie92208 Posted January 21, 2019 RMweb Premium Share Posted January 21, 2019 Just back from a few weeks in France. The journey back, unusually using le Shuttle, involved a lot of mileage alongside high speed electrified lines, including HS1. I still do not understand why GWML needs such monstrosities of structures to support its OHE when those high-speed lines do not. I believe that the main reason is that the GWML has to be set up for relatively closely spaced pantographs on 387's and 5 car 800's. These create lots more problems for the designers than either an 18 car Eurostar or 2 TGV's coupled up where the pantographs are much further apart. The resultant forces demand a much higher tension and consequently beefier structures. Jamie Link to post Share on other sites More sharing options...
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