To me that should be OHLE, as it's a single change from 3rd rail to OHLE after Basingstoke, and it then continues away from the 3rd rail "heartland". Exeter, at some point will get wires for the GWR services to Bristol and Reading anyway, so it would be silly to have 3rd rail joining on another line.
ORR doesn’t make laws, it manages compliance with them.
Dudding Hill line.
Pudding Lane is the famous one. A baker that’s not in Bakers.
I would actually argue for an extension of the Third Rail down to Exeter. It would avoid rebuilding a lot of tunnels (Fisherton being a particularly bad one off the top of my head), it would be less of a headache with the obscenely backwards NIMBY-culture of the people down South, and it would avoid mandating a stop at Overton (not all trains stop at Overton, so unless the panto can be lowered on-the-go, an added stop at Overton would cause quite an increase in travel times).
Though it provided a perfect test bed for Merseyrail's new battery-equipped rolling stock, so while the scheme on its own it may have qualified for a 'minor extension', the value to prove the trains for possible future more lengthy excursions off the juice rail, was higher.
Either elevated, tunneled or high security fenced throughout with no level crossings. ISTR they implemented a range of additional measures for staff and passenger safety too.
Third Rail does require gauging work on it's own, as it is an additional obstruction in the lower sector gauge. Obviously not as much as OLE, but it's not an automatic fit.
'down South'.. Not as if there aren't NIMBY's in the north (leaving aside the fact the South-West has it's own beef with the London area). Any investment in the railway will need to be accompanied with big housing developments to justify it so the idea that Third Rail will magic-wand NIMBY objections away is somewhat optimsitic.
Changing on the fly is long-established. Eurostar used to do it all the time, and 80x change from Diesel to panto on the fly daily.
You should separate the problems caused by the legislation and the problems caused by the interpretation. In each scheme, the two elements will have different levels of impact.
Don’t think the WoE Line from Basingstoke to Exeter can really be regarded as “infill”
And therein lies the problem. You are not approaching the issue level-headedly, but banging on the pub table screaming "MORE TRAINS!"
Maybe they could operate on battery power through the tunnels. It's not as if it's a high speed line.
It might help to diffuse some opposition relating to visual impact of a wired alternative.
If a dual voltage train had a short-range traction battery fitted, it could lower its pantograph and continue through an extended gap section under power at speed, then pick up the third rail a little beyond (and vice versa). That could minimise or even eliminate any dual voltage equipped track, disliked for oft-discussed traction return current and earthing reasons. A really good electrical isolation could thereby be obtained between the two supply systems. Trains' ability to traverse long gaps in either 3rd rail or OHLE systems could allow non-provision of full conductor coverage through large junctions where cost and complexity is high. Lower complexity would likely lead to increased reliability and also improved staff safety with all the small sections of conductor and their connecting cables within existing 3rd rail junctions removed as failure and trip hazards. Making all EMUs BEMUS has great potential.
Very limited, NIMBY's will find anything to complain about.
Tbh you could coast through that gap, it's not too dissimilar to a OHNS.
For third rail this is indeed an advantage, so long as the BEMU is configured to offer a 'blended' power mix dynamically responding to the available power from the shoes. I think OLE would benefit less from this as the need to lower and raise the pantograph to prevent dewirements would counteract much of the benefits of the less complex knitting.
An all-BEMU fleet, with some extended range BEMUs is already coming. The complete new Merseyrail fleet is BEMU, with some extended range editions. As I understand it, this also involved de-electrification of some third rail in the depot.
Agree they'll latch on to any factor if its a controversial new railway scheme.
True, though with batteries it could be done without risk at any speed, which might permit gaps to be sited closer to a station or junction than would be permitted for coasting alone.
South Wales Metro is doing this in the Valleys. They're using auto pantograph raising and lowering controlled by a system based on eurobalises. An interesting project to watch.
100%. The resilience effect of batteries struck me when reading about the Rennes line B autonomous metro, implemented using rubber-tired Neoval technology, now offered by Siemens. This has a twin conductor ground power supply that extends along plain line sections, but is gapped significantly through junctions. To cope with this and unelelectrified depot tracks, trains have traction batteries that ensure they can alway negotiate the gaps and any failures encountered. The availability quoted for the vehicles is a frankly astonishing 100%, I think largely driven by their ability to autonomously power out of any kind of supply glitch. I find it interesting that the first UK DC discontinuous battery scheme proposed also involves Siemens, who built and maintain the Desiro fleet that might be adapted.
Ah, I hadn't realised they were all BEMU, that's good to hear. Depots are another case where BEMUs make an incredible amount of sense.
Good point
Thanks, I shall check up on those.
The problem with this is it's not a well-enough used line to get that sort of electrification approved: 2tph to Salisbury then 1tph from there to Exeter; there are several lines not currently electrified that have a much higher frequency and could do with OHLE as a higher priority.
With Exeter hopefully getting AC at some point I as hoping for dual voltage BEMUs to ease infrastructure complications (and my excitable crayons want Basingstoke/Salisbury/Southampton as AC for freight!)
It would be more than one wouldn't it - one coming and one going??
Sure I read that that was the plan and it still wasnt enough 3rd rail miles to make it work. Technology may have moved on.
The parked to charge suggestion was if the turnarounds wouldn't allow sufficient charging time.
Reeves etc seemed to be suggesting leaning on the regulators - they sacked the head of one that was too strict didn't they?
Who? My memory isn't great but I thought it came from a senior internal bod/document, rather than being just gossip/guesswork??
In the very long-term I'd like the Hampshire end of the SW division to transfer to AC (boundaries at roughly Farnborough and Fareham) but I'd not want that to happen until other places (Sheffield, Bristol/Exeter/Plymouth, Hull, Chester) have got wires at all!
1tph in each direction yes, but I'm assuming the outbound train would be fully charged by the time it's travelled from Hurst Green to London Bridge and laid over.
Not sure why it wouldn't be enough, the East Coastway can handle 12-car Londons from Eastbourne to Lewes and the distance + layover on the juice from Ore to Brighton and back would happily exceed the distance from Ore to Ashford and Back (and there's a top-up at Ashford available). Happy to be proved wrong by somebody who's got technical knowledge of the electrification system though.
Given the amount of third rail existing which isn't going to be ripped out I wouldn't have thought there are many places where turnrounds couldn't be sufficient in the third rail area. Turnround charging would be a bigger problem in the AC area where branches are a bit longer and electrification isn't as comprehensive.
The turnaround time is more about stock and crew schedules than third rail v AC isn’t it?
How do they ensure the battery doesn’t make an isolated 3rd rail live, and making that fail safe?
It might not be top priority, but at some point they'll have to stop running diesels down the the line, so a mix of OHLE and battery will have to happen at some point.
Why would that be necessary when the timetable and rostering had been set up with appropriate capability to maintain sufficient charge for the service?
