3rd rail vs OHLE

norbitonflyer

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Wouldn't Ashford - Ore be better at 25kv AC as there are aspirations to operate services over it to St Pancras via HS1?
Class 395s can operate on the 3rd rail, so HS1 services would be possible whichever electrification system is used. 3rd rail would allow through services along the coast as well.
 
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Bald Rick

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It'd require rather more careful fleet allocation (assuming things remain as they are; with southern operating the through services, and only retain the 377/2 and /7 DV fleets)

Don’t forget the 387s, of which GTR have plenty.
 

zwk500

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Wouldn't Ashford - Ore be better at 25kv AC as there are aspirations to operate services over it to St Pancras via HS1?
Aspirations of one MP, who is no longer in office.
I've seen it stated elsewhere that the Uckfield line can't take Mk 3 EMUs; does anybody know the reasons why? Are the problems preventing them from running major?
The reverse curve in Oxted tunnel. It's covered on the Uckfield line thread with a very good photo. Solving it requires boring a 2nd tunnel to permit straightening the line in the original tunnel.
 

Nicholas Lewis

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So would OLE!
Perfect line for OLE if they don't change the track layout too much. Only one brick arched bridge across the double track section North of Appledore might need rebuilding all other structures would be clear for OLE even Ore Tunnel if it was kept single line then pop back onto the third rail at Ore. With so much single line 25kV makes absolute sense compared to additional substations the single line would necessitate if it was DC. Also using a static frequency converter could possibly provide 25kV infeed off the existing 33kV connection that NR has at Hastings Grid to avoid having to get a new grid connection.

Nice conversation with ORR perhaps to trade Uckfield for limited DC extension to Edenbridge battery for remainder and 25kV for Ashford to Hastings.
 

Nicholas Lewis

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The newly published rail-environment-policy-statement.pdf has this interesting statement on third rail
DfT, Network Rail, Office for Rail and Road (ORR), and RSSB are working together to explore options for safer versions of third rail electrification.
which im surmising will see a industry wide response once RSSB project

21st Century DC electrification infill (T1214)

is published towards end of the year.
 

zwk500

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Sorry, that might be partially true (if your thinking of Amber Rudd), but a question was asked about it during PMQs on 21 July - I think it was by the current MP for Hastings and Rye
Being asked about in PMQs is very different from having serious weight behind it.
 

Meerkat

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Being asked about in PMQs is very different from having serious weight behind it.
The Guildford MP asked about putting the A3 in a tunnel under Guildford!
Thats how credible a question in PMQs is!
 

Meerkat

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True; I can't remember exactly what Boris said in reply, but the impression I gained from it was that it wasn't dead
Politicians are usually careful to never say never - leave the questioner with the thought they might get what they want without giving any guarantee of any kind.
 

zwk500

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Politicians are usually careful to never say never - leave the questioner with the thought they might get what they want without giving any guarantee of any kind.
This. Very much. Although Boris also has a habit of saying 'yes' without having checked if somethings possible first (see Thames estuary Airport and Garden Bridge among others)
 

QueensCurve

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I think you're not being entirely fair.

On the LSWR (3rd rail) vs LBSC (OHL) decision by Southern, part of it was driven by the technology of the time, the DC technology was "better" it that it was more established. AC was still at an early stage (bearing in mind this is pre 1925) and when merged to form the Southern railway, the route miles of 3rd rail far outweighed those of the OHL. It's also worth remembering much of the early AC electrical equipment originated in Germany or Switzerland - the former was a bit problematic in the immediate post WW1 period.

DC OHL - the LNER had planned those before WW2 as you said and they were completed in the 1950s. At this time 25kv was still fairly experimental - DB had done some AC OHL before the war, at 20kv rather than 25kv and it was this that the French copied in the early 50s, but in parallel they continued to electrify using 1500v DC and other European countries continued with 1500v or 3000v DC. In some ways rather than the UK govt being the last to have 'the penny drop' they were actually early adopters of 25kv AC for widespread electrification - which has become the 'standard' AC system.
High voltage AC was pioneered by the Bern Lötschberg Simplon (BLS) railway in Switzerland. It used 15kV at low frequency (16 2/3 Hz). It was originally supplied by frequency converters of the Forces Mortice Bernois (FMB). Low frequency was adopted because of problems starting trains with Industrial frequency AC. The system was adopted as standard in Switzerland (although 11Kv is used on meter gauge lines for some reason). It aslo became the standard system in Germany, Austria, Norway, Sweden and other countries.

True; I can't remember exactly what Boris said in reply, but the impression I gained from it was that it wasn't dead
"Boris" klaxon. Even Johnson's name is a lie. It is actually "Al"
 

JamesT

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"Boris" klaxon. Even Johnson's name is a lie. It is actually "Al"
Alexander may be the name he was given by his parents, but in the UK your name is whatever you are customarily known as. So his name is Boris Johnson.
 

Bald Rick

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How thorough? A quick options check and “that will be ’challenging’ and chuffing expensive”?
We’re off topic, but some initial feasibility, and yes it was v expensive. Not particularly difficult engineering wise. It was in the context of a lot of new homes in the borough and further south. Being old enough to remember when the current A3 was built through Guildford, it felt a bit weird when I saw it!
 

AM9

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How thorough? A quick options check and “that will be ’challenging’ and chuffing expensive”?

Note:, I've spent some time putting this response together and as usual Bald Rick has beaten me to it, but here is the way that I could imagine it.

Maybe not as difficult as it superficially looks. I doubt it would tunnel completely under Guildford, - probably starting the bridge under the northbound SW main line, instead of climbing up to clear the Dennis roundabout, take a slight fall and pass under it, resume the climb under the existing alignment (there's so many slips on and off the current 2+2 lane road that there is probably enough room the make it 3+3 lanes without further subterranean land take). The rise to the existing line could be completed before the Guildford Holiday Inn from where the only non trunk access to the A3 is the ridiculous Beechcroft Drive/Manor Way skewed junction.*
I'm not presuming that it wouldn't be an expensive programme, or that it wouldn't be quite disruptive in it's implementation, but the cut and cover activities aren't exactly novel, (M25 Holmesdale Tunnel, A1(M) Hatfield Tunnel etc.), and it would use the gradient down to the railway bridge to avoid the river, and by choosing the correct points to climb that end of the Hog's Back ridge, the gradients would be perfectly acceptable fo a trunk road. The rise from the railway bridge to the Holiday Inn is about 42m in 1.84 km and the current road falls on the western side of the Dennis rounndabout with an almost level stretch past the Midleton Road and Egerton Road junction. Thus there are opportunities to adjust the tunnel gradients as required.
* This junction should really not be there and be replaced with a two lane flyover with southbound A3 access via the Farnham Road slip.
 

HSTEd

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How thorough? A quick options check and “that will be ’challenging’ and chuffing expensive”?

Such a tunnel is certainly within our engineering capability - and whilst it would be very expensive, having the A3 go through the centre of Guildford is hardly an ideal situation.
 

vic-rijrode

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The Guildford MP asked about putting the A3 in a tunnel under Guildford!
Thats how credible a question in PMQs is!
It might be better to examine the possibility of putting Guildford in a tunnel under the A3. Lovely place....
 

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