GRALISTAIR
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Surely Thames Valley would come first as that scheme already has had government blessing?
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North Downs line electrification
- Thread starter Philip Phlopp
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Surely Thames Valley would come first as that scheme already has had government blessing?
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I was thinking along the lines of the Marlow Branch, which AFAIK doesn't have government blessing. My thinking is that if you are going to release some of the 16xs, you might as well bite the bullet and release them all
SpacePhoenix
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The Marlow branch is likely to remain as a DMU operated branch due to the very limited clearance in the platforms at Bourne End station.
Philip Phlopp
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North Downs Line wasn't intended for electrification as part of the GWep, so there's no great issues with keeping DMU stock there until it can be fitted in at an appropriate time for electrification, or indeed, the IPEMU route is taken prior to infill electrification.
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There are issues with it remaining DMU operated - both technical and political - which could push some sort of solution. It won't be cheap to resolve but it is a bullet that will have to be bitten.
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smiffy9373
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No reason why the new franchise owner in 2019 can't specify the Stadler electro diesels that Anglia are getting as an add on order for the Thames valley branches and the Gatwick services. That releases all the 165s to Bristol.
Mind you after seeing the Anglia winning bid it wouldn't surprise me if the new owner orders a complete new fleet of EDMU for Bristol releasing the 16X to Exeter with all the 15X going.
Mind you after seeing the Anglia winning bid it wouldn't surprise me if the new owner orders a complete new fleet of EDMU for Bristol releasing the 16X to Exeter with all the 15X going.
Philip Phlopp
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The North Downs Line doesn't need anything as complicated as a bi-mode unit, it just needs a bog standard Electrostar with a battery pack, which can remain a sub-fleet of an otherwise standard single fleet of EMU stock.
The line is perfect for a battery unit thanks to the circular diagram each unit works which provides a very long period on 750V DC to charge at either end of the route (Wokingham-Reading-Wokingham and Redhill-Gatwick-Redhill with 10 minutes at Reading and Gatwick to continue charging).
The Thames Valley branches (other than Marlow) are being electrified and sufficient stock is on order to allow for their conversion from DMU to EMU operation.
It's only Marlow which is out at the moment, and it's because it presents an issue for EMU stock because of platform length - it's no better for a Stadler bi-mode unit. If you can make a Stadler bi-mode unit fit, you would just make a normal EMU fit.
swt_passenger
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...and not forgetting there's a fairly reasonable chunk of third rail for a top up in the middle as well, I forget the actual junction names though.
Philip Phlopp
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Aldershot South Jn to Shalford Jn, for 8 miles. It may be desirable to extend the third rail to North Camp and Shalford, so there's a convenient station at either end to hold a unit whilst still being able to re-charge the battery pack, that takes you to 10 miles.
So if a DC IPEMU with batteries was the chosen motive power solution for the North Downs, I wonder if that makes the whole route a better fit with Southern as the TOC, assuming that company were to also get similar units for working Uckfield and Marshlink services. That would also facilitate combining the Redhill terminating stoppers with London - Reigate terminators to offer more through journey opportunities. Can't see the public being very keen on such a change at the moment though!
edwin_m
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Seems reasonable, leaving the present "little local difficulties" aside. If nothing else GWR otherwise has no particular reason to have EMUs with an enabled third rail capability and probably none to have IPEMUs either.
Minstral25
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I think you would find the reverse in that the public would be very keen. Reigate is a very busy station towards London and 1 train per hour is insufficient, in the evenings when there is no through service, the timing of London trains at Redhill means many connections are in the 20-40 minutes region at Redhill.
A regular 2 trains per hour all day service between Reigate and London is likely to see a doubling of passenger numbers at Reigate, plus probably a serious increase at Dorking Deepdene/West if extended to Guildford.
Have we succeeded in getting a Volte face? We have. You argued that even a small third rail infill on the hilly bits of the Ashford Hastings line was verboten.
Well done. It's good to be as flexible as a battery pack emu. I am going to be the sceptic. Powering 40 tonnes coaches by battery day in day out is still a terrific challenge & the expense of batteries,their short life time under tough powering/charging cycles,& their disposal might frighten us off the idea. But it is great in principle. But so were the new technologies that some Dft whizz kid recommended a few years ago that would save more knitting. His report was lampooned by Old Ford of Modern Rail.
Philip Phlopp
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It's not quite a volte face, it's just a scheme which has some unique issues and potential problems, so a small exemption is in order.
Aldershot South Junction and Shalford Junction are at either end of lengthy un-electrified sections, if there's disruption, point failures, signalling issues etc, it's clearly going to be desirable to platform stock where there's 750V DC available to re-charge, so extending to North Camp or Shalford makes sense, particularly as it won't need altered feeding arrangements.
The battery packs that Bombardier and Network Rail tested under the Class 379 unit (and which were still undergoing static testing until recently) have proved to be reliable, safe and demonstrate good energy density. They're Lithium Ion Phosphate batteries, so not the best when it comes to energy density, but good for longer term, high power applications.
The battery packs have a life expectancy of 5 years which suits upgrades, cascades and rolling out electrification. They're not cheap, the leasing costs on them come out to something not far short of a unit on its own (though going down all the time) but the business case stacks up if you can cascade away DMU stock and stretch an existing EMU fleet to cover, or you can extend an EMU operated service beyond the limit of electrification and generate additional traffic/revenue.
coppercapped
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Eh? The Class 387s, which GWR is now receiving, have enabled 3rd rail equipment. So a battery fitted EMU would not be too different.
Through services such as Oxford or Newbury to Gatwick would then become possible quite easily.
SpacePhoenix
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All modern AC units likely have all the internal stuff already in place to enable them to run on the 3rd rail if needed to in the future
Putting down a poster who dared suggesting DC infill. It's good to be flexible & change your mind.
QueensCurve
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The point presumably being that no new feeding arrangements are needed. It is just the installation of the conductor rail itself.
Philip Phlopp
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Yes (with caveats) but we're talking about Class 387 units which are a dual voltage units with shoe gear, currently working on both AC and DC routes.
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It's not infill though, is it ? It would be a modest extension of two miles to enable more efficient IPEMU operation (which is needed because third rail infill isn't an option). There would also have to be some adjustment of third rail boundaries if/when the remainder of the route is infilled at 25kV AC, modification of third rail to enable voltage changeover is relatively easy to get ORR approval for and doing a voltage changeover in a station, whilst not essential, is sensible.
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Yes, as previously stated.
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Surely it should be the squandering of public funds on changing one perfectly serviceable electrification system to another which happens to be flavour-of-the-month to the techies, incompatible with all the lines it crosses, causing great disruption during its installation, and introducing all the voltage changeover point unreliability at Redhill etc, that should Not Be An Option.
Why was Surrey Quays to Peckham Rye, a newly-built route, allowed in the last couple of years to be infill 3rd rail when dual voltage units were employed?
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I wouldn't call every major new scheme since the 1950's to quite be 'flavour of the month', but don't let facts get in the way of your rant.
Philip Phlopp
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A couple of points - again going over ancient ground here
a) North Downs 750V DC to 25kV hasn't yet progressed, IPEMU is being discussed as an option here in place of converting the whole route to 25kV AC with the difficulties that would entail for other operators.
b) Electric Spine 750V DC to 25kV still isn't fully committed for CP6, but it won't come at any squandering of public funds, life expired DC equipment will be removed and replaced with less expensive AC equipment, ongoing cost savings will be realised through reduced electrical losses, and further positive financial benefits are realised through increased electrical supply capacity which will enable freight to convert to electric traction, for longer and more frequent services, opening up new destinations as track capacity permits
c) Third rail was perfectly serviceable, it's growing less serviceable as demand on the system increases. It's costly to increase capacity on the system thanks to the complex way power is taken from National Grid and transformed to 750V DC for the third rail and resistance losses increase as power draw increases.
It's an incontrovertible fact that stock is limited to lower speeds, lower acceleration and shorter formation lengths as a result of limitations on the DC system. The potential to operate services at 110mph using AC would release considerable capacity, which returns to the argument at (b) which counters your argument that public funds would be squandered, the opposite is true.
And when it comes to the TfL Overground, they got in before ORR firmed up the Energy TSI compliance documentation. The safety case undoubtedly benefited from being in the planning stage long, long before DC to AC conversion became policy in the 2012 HLOS with Electric Spine. I can't envisage doing it any other way, but it was an astonishing failing of the TfL Overground works not to use the rebuilding opportunity to do DC to AC conversion, maybe less so for passenger use, but certainly from a freight perspective. It really is all a terrible mess thanks to the lack of a proper electrification strategy being in place at the time.
Hopefully that's not the case going forward.
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swt_passenger
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TfL are also re-routing the Met into Watford Jn using third and fourth rail DC, and just like the SLL link mentioned above it is only a very short link between existing systems.
By describing the link in terms of stations at either end, "Surrey Quays to Peckham Rye" rather exaggerates the distance anyway - the distance of reopened track between the junctions with the ELL and existing SLL is significantly shorter, only a little over a kilometre, and in any case Queens Rd Peckham would have been the relevant station to mention anyway.
It isn't black and white, there will always be some justifiable exceptions to a revised policy.
By describing the link in terms of stations at either end, "Surrey Quays to Peckham Rye" rather exaggerates the distance anyway - the distance of reopened track between the junctions with the ELL and existing SLL is significantly shorter, only a little over a kilometre, and in any case Queens Rd Peckham would have been the relevant station to mention anyway.
It isn't black and white, there will always be some justifiable exceptions to a revised policy.
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Let's live in the real world rather than the world of the bureaucrat. TfL third railing the Overground extensions saved millions compared with your AC advocacy. And has it been more dangerous? In the real world has it been more dangerous in the real,rather armchair risk assessment world you advocate? No we have saved millions,done the job quickly & no one has since been hurt. Third rail is dangerous from your armchair. It is safe in practice. You have been unable to quote real world stats, only risk tabletop assessments.
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I don't know what you mean by 'the real world' but it is patently obvious that an exposed conductor at floor level is more likely to result in accidental death and injury than an exposed conductor suspended 4.5m in the air.
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In the casee of ELL only a little more distance than say a new connecting chord to make a triangular junction in the middle of a predominantly DC area.
The Croxley link is longer, but there's no reasonable prospect of equipping LUL S stock with AC and it is also a Metro like railway with fairly short lightweight trains, hence well known demand and (being new) the feeds can be designed accordingly.
Both lines are in urban areas, with very secure fencing and no level crossings for public or livestock to gain illegal access.
Modern design principles are employed for ease of isolation and strict rules for maintenance staff access only whilst isolated.
So in both cases a short urban metro extension, perhaps the only ideal application for 3rd rail remaining (except the short extensions for optimised changeover locations as suggested by Mr Phlopp.
Agreed, but no 'significant' extensions. Shalford to Reigate DC would be a rural nightmare to engineer with the safety of level crossings and unmanned stations to consider, not to mention the HV feeding arrangements for the additional substations required.
Philip Phlopp
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The risk assessments done for third rail use real world data, the data used comes directly from SMIS. Next.
After challenge you eventually pointed us to the research,a desk top assessment of risk,not based on real fatalities or injuries,& with subjectively weighted variables. An LSE academic saw it and chortled.
You & your shadow (not Marky,the ace track designer I hasten to add,who is always worth considering) persistently ignore that an armchair assessment is subjective. The proper measure is the real injury stats AC v DC, weighted for diff populations that dc & Ohl go through, & track length. That you ignore it speaks for itself.
The survey you pointed us to reminds me of the London Overground bridge east of their Clapham junc platforms. Silverlink trains used to glide into platform 2 at 25mph. When the Overground took over, NR cut the limit to 10mph. Exasperating for drivers, & passengers all of whom wanted to catch another train.
Some drivers actually love the railway,so on their behalf ASLEF asked the Overground via LOROL if the new PSR could be raised. No said NR. "Our consultant engineer said it had to be 10 mph." A year later an FOI request was put in. Guess what. Apparently NR had asked the engineer "Is the bridge suitable for 10mph?" He said yes. Did your desk top risk assessment also answer a bigoted question. Incidentally NR begrudgingly raised the PSR to 15 mph last year.
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Philip Phlopp
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The risk assessment uses data on real fatalities and real injuries which have been logged into the industry wide SMIS database by the industry itself, I don't really see how a risk assessment could be done otherwise.
The risk assessment is not (in my opinion) subjectively weighted, but I'd be open to discussion with you or the LSE academic who saw it and chortled, about why you think it is subjectively weighted.
Did it answer a bigoted question - no, how can it have done, unless the industry itself is over reporting injuries on 750V DC and under reporting injuries on 25kV AC.
I know there are shortcomings of 'armchair' assessments, and I know we always err on the side of caution, but there's really no other way to ensure the railway is a safe environment. We can't do destructive testing on structures or gather up hundreds of volunteers and kill them, that's why everything is done using risk assessments.
And given we're all enthusiasts and only want what's best for passengers and freight on the railway, could you drop the hostility. People have different opinions to you, get over it. The reality of the situation is there's hundreds of engineers, scientists and civil servants at Network Rail, ORR and RSSB who disagree with you, which is why 25kV AC is being pursued. It's not a perfect electrification system, and I don't think anybody really claims it is, but it is a better system than 750V DC third rail which is why it's now the preferred, default electrification system.
If you could please avoid sulking and taking it out on me all the time, it really would be most appreciated, your behaviour does create something of a corrosive atmosphere. I know I'm not alone in thinking that.
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