Ben
fotopic... whats that?
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Post by Ben on Aug 7, 2009 1:30:30 GMT
A quick nip over to London Reconnections the other week and I read the artical on the new electrification schemes in the pipeline. There was a link to Network Rails report from back in May about route electrification, which went through most lines in the country and rated them on their electrification merits. Its fascinating reading if you like that and have a spare half hour. Anyway, one of the lines thus rated was the London Aylesbury line via Harrow, and in the plan it was envisaged that OHLE would take the line, and indeed the rest of the Chiltern route. However, for some other lines on the frindges of AC and DC electrification both systems were put forward for options. Its very clear that DC is, for new schemes, a dead duck. Indeed its limited in the report to short infil schemes; even a fairly lengthy southern region line (I forget which) was only considered for AC, with only the briefest note saying that DC wasnt cost effective or something. But my question is about the Chiltern Line. No mention of anything other than AC was made for the route via Harrow, despite the fact that about half of the route between Harrow and Aylesbury is already DC. Unless there are viable plans to extend the Aylesbury Line, and as part of those plans running trains via the Met route is integral, would it not make some sense to just extend the 4th rail to Aylesbury? Considering that it'd have a OHLE route via Princess Risbrough anyway, and possibly the route via Aynho Jnct and/or a completely new route to join further up if (or rather when) services are reintroduced north from Aylesbury, surely unless the Met route is strategically important it could just be segregated? I mean which would cost more, OHLE from Neasden Jnct to Aylesbury, or 4 rail from Ammersham? Thats a semi serious question though   Anyway, what do people think? |
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roythebus
Pleased to say the restoration of BEA coach MLL738 is as complete as it can be, now restoring MLL721
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Post by roythebus on Aug 7, 2009 7:58:49 GMT
In my view it would make sense to have the Aylesbury line done at 25kv, even if it means having a dual system from Marylebone. the OHLE is not (usually) susceptible to icing up like any surface contact rail. the dual system has already been proven on the Euston-Watford line and other places, so what's the problem?
The major additional cost would be immunising the LT signalling along the route.
IIRC the Southern infill section is Ashford-Hastings. It would be very sensible to electrify this last outpost of diesel operation, and with the greater availablity of dual voltage rolling stock, I don't see many compatability problmes, Remember, Ashford already has 25kv ac and 750v dc!
I think any new 3rd/4th rail extensions except short infills is a no-brainer in this day and age.
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Post by suncloud on Aug 7, 2009 8:22:53 GMT
Certainly Southern already have dual-voltage stock in use, and the electostar fleet appear to have been constructed to accept OHL equipment at a later point.
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mrfs42
71E25683904T 172E6538094T
Big Hair Day
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Post by mrfs42 on Aug 7, 2009 8:25:54 GMT
I think it is now a design requirement that all 3rd rail EMUs have to have a space on the roof for a pan to be mounted.
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Post by amershamsi on Aug 7, 2009 10:48:52 GMT
I think any new 3rd/4th rail extensions except short infills is a no-brainer in this day and age. Aylesbury-Amersham is a short infill! And there isn't going to be any problems with icing and so on that don't happen with the Met. Then again dual voltage stock would easily allow, OHLE from Amersham-Aylesbury, with 4th rail down to Harrow, where OHLE picks up again to Marylebone. The problem I see is simply "why?" when the other Chiltern route has an awful BCR for electrification (even though it's now proposed, the previous document, that had about the same MML and GWML BCRs had the Chiltern Route at 0.5). I've just re-read the document and cannot find anything to suggest that Aylesbury via Amersham had a 1 or better BCR and was worth doing, and thus all this is moot. Ashford-Ore and Uckfield were proposed with DC, Aylesbury via Amersham was vague as to which system would be used. |
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Deleted
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Post by Deleted on Aug 7, 2009 11:21:57 GMT
I'd quite like it if the London-Aylesbury line was electrified, I think diesel is past it now. Also very noisy on the 165s, especially when you're used to the c2c 357s! I can see many objections to OHLE in Aylesbury, people here seem to be very particular about their landscape being blotted.
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Post by Dstock7080 on Aug 7, 2009 12:18:43 GMT
The Chiltern Railways franchise is currently due to end in 2022, when the oldest 165s will be around 32yrs old - so i guess this would be around a good time to think carefully about the future electrification.
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Deleted
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Post by Deleted on Aug 7, 2009 17:37:36 GMT
There are problems which nobody has yet mentioned. The track between Harrow and Amersham is LU owned and maintained whilst any OHLE equipment will presumably be National Rail owned who will maintain it, and what happens when current is needed off in an emergency, will the OHLE and forth rail current sections be tied in to be able to be switched off together? Currently no LU train runs under OHLE so will the S stock and all engineers trains need special equipment and electrical isolation before running under it?
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Ben
fotopic... whats that?
Posts: 4,282
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Post by Ben on Aug 7, 2009 17:48:20 GMT
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roythebus
Pleased to say the restoration of BEA coach MLL738 is as complete as it can be, now restoring MLL721
Posts: 1,256
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Post by roythebus on Aug 7, 2009 18:33:22 GMT
Underground stock runs alongside OHLE in a number of places and the equipment on the trains has been designed to cope with it.
I'm not saying Amersham-Aylesbury is a short infill. there certainly have been problems on the Met with icing. they used to have to pass a warming current through the juice rails to try to prevent them icing up!
Another problem with diesel units is that they need new engines every 4 years or so. I know because my son happens to be a fleet engineer at Selhurst, and all the Marsh line units fell to pieces at the same time!
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Deleted
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Post by Deleted on Aug 7, 2009 19:38:10 GMT
Underground stock runs alongside OHLE in a number of places and the equipment on the trains has been designed to cope with it. We run alongside the lines, but not under them so we have no current risk of a train touching a loose or broken wire. |
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Post by andypurk on Aug 7, 2009 19:54:33 GMT
Underground stock runs alongside OHLE in a number of places and the equipment on the trains has been designed to cope with it. We run alongside the lines, but not under them so we have no current risk of a train touching a loose or broken wire. Well, except all the sections with LU lines alongside Network Rail lines. For example the Bakerloo line alongside the West Coast mainline, where when the wires came down at North Wembley Junction in January, they fell onto the DC electrified tracks where the Bakerloo line runs. The same could potentially happen on the District line along side the Bow - Barking - Upminster section, on the Central line at Ealing Broadway or Stratford, the Victoria line at Northumberland Park depot, the Hammersmith and City from Paddington - Westbourne Park and so on. You have to remember that the overhead wires are miles in length, not just a few meters and can come down over the whole formation when there is a problem. |
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mrfs42
71E25683904T 172E6538094T
Big Hair Day
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Post by mrfs42 on Aug 7, 2009 23:12:57 GMT
You have to remember that the overhead wires are miles in length, not just a few meters and can come down over the whole formation when there is a problem. Yeah; but the leakage detection is more sensitive than LU.  |
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