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Post by phil on Nov 20, 2015 20:25:45 GMT
Quite so, but what other routes are there? I'm not going to plough through your long list of points. I think CR2 is too complex and potentially inoperable. I think the answers for N/NE London and the Central area are different from those needed in S/SW London. I'd much rather see a comprehensive strategy of building new automatic tube lines giving high capacity, high frequency services. The trains certainly don't need to be to traditional tube profile. Let's face it the politicians have NO strategy for the tube apart from continuing upgrades to the point where nothing more can be done. The two current extensions don't add much and yet there are vast areas of London that require high capacity, high frequency services. Paris has it right - it makes long term strategic improvements across a range of modes covering Paris and the wider Ile de France region / départments. We can't even think like that never mind make it happen. As usual I am a lone voice wailing in the wilderness and that's perfectly fine. I'll keep my felt tip pens locked away in the drawer. Oh there are plenty who agree with you on that score - for starters I think its a bit ridiculous joining the Lea Valley lines so far out - if the portal was at near Clapton for example Chingford line trains could be added into the mix. However what I recognise is that doing nothing is not an option and if all that the DfT or TfL are prepared to finance is the current CR2 variant - warts and all - then its better than nothing. What you and other like minded folk to need realise is that as with HS2, the Treasury are NOT saying "here is a pot of money to be spent on transport improvements", they are saying "we will give a lump sum SPECIFICALLY FOR HS2 / CR2 and if that doesn't happen we will keep the money and use it to pay off the deficit" . In other words it cannot be diverted to any other transport scheme and opposing CR2 on grounds that it isn't an ideal scheme will not change that - with the end result being London gets nothing.
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Post by phil on Nov 20, 2015 20:10:17 GMT
On the fixed points, I've also been assuming that Wimbledon, Victoria, TCR and Euston are fixed points. I'm less convinced that Clapham Junction needs to be a fixed point however (Wimbledon - Balham - Battersea Power - Victoria would not be a bad route for example with plenty of trains still from Wimbledon to Clapham Junction). The thing about not calling at Clapham Junction is you lose easy interchange with Overground services plus Windsor line trains. Also many outer suburban trains do not stop at Wimbledon, but they DO at Capham Junction to facilitate interchange with Southern and Overground services. TfL have also said that if CR2 is built via Clapham Junction it makes it a bit easier to extend the Northern line branch there from Battersea as it hopefully won't be to overloaded by doing so (though this may be on the assumption CR2 gets a Northern line interchange at Tooting)
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Post by phil on Nov 18, 2015 20:09:45 GMT
The other thing is that the less changes you have to make to get to work, the more likely you will be to use it. And no-one wants to make changes going to the theatre, football or whatever, either. Especially coming home from them. The whole thing at present indeed seems to be trying to serve too many masters for its' own good. And if you say to the consultation people, at the public sessions, that you aren't convinced about the route you don't get a very positive reception! Quite so, but what other routes are there? Firstly people need to get it into their heads that the Government will only part fund ONE crossrail line at a time, thus there is NO GUARANTEE whatsoever that they will look favourably on a CR3 after CR2. As a consequence it is very much a case of doing the best you can with CR2 and not counting on CR3, CR4, to pick up the bits you miss. Secondly thanks to Londons Geography it is very difficult if not impossible to devise a realistic route for a North East - South West ish tube line that serves both the City / Docklands and the West end. Thirdly CR2 is being promoted by TfL who naturally care less about existing national rail users than users of other TfL services (i.e. the tube) and as such any Crossrail proposal with TfL in the lead has to do something for the parts of the tube network under greatest pressure. Fourthly As much as it grates with some, TfL have said that Euston MUST be served by CR2 so as to help disperse passengers from HS2. It is not acceptable to simply say such a need can be left to any CR3 / CR4 etc (see point1) Fifthly, NR have proved that the SWML is running at capacity in the peaks and as such CR2 is the most cost effective way of solving that particular problem - again it is unacceptable to simply leave things as they are just in case a CR3 turns up a few decades from now. The current routing points therefore of Wimbledon -Clapham Junction - Victoria - Euston (and St Pancras / Kings Cross) are non negotiable fixed points that CR2 has to serve. Yes the NE section has the potential to go elsewhere (e.g. it could do a Jubilee and head east then south for example) but doing so does not fit with TfLs desire to provide relief for the Picadilly and Victoria lines. So while yes amendments to the route are possible, those that do not respect the above points will be rejected outright as they do not comply with the base requirements. Finally I note that there is a suggestion that CR2 could take over one of the CR1 branches in the East as part of a revised routing . The BIG PROBLEM with this solution (which the proposer ignores) is the simple fact that the design of CR1 has not factored this eventuality into its design. Building a junction box tunnel round an operational small diameter tube line is hard enough but doing so around the much larger diameter Crossrail tunnels is a far grater problem. Had such an eventuality been factored into the design of CR1 it would be easy, but as it stands undertaking such works to what will shortly be an operational railway is a non starter. However while the opportunity has gone as far as CR1 branch takeovers the same does not need to happen with CR2. It would for example be perfectly possible to design in a couple of junction tunnels say after angel so that a future CR3 & CR2 could swap branches - but that does rather constrain any potential CR3 routing, which in itself may never happen anyway.
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Post by phil on Nov 13, 2015 23:51:35 GMT
It is important to remember that leaf debris build up is not laughing matter - if it track circuits do not operate correctly or drivers cannot stop in time then I refer you to pictures of Clapham Junction (1987) or Purley in (1989) to see the worst case results. To avoid any confusion, it should be stressed that neither of those accidents were actually caused by slippery rail conditions - they were respectively a wrong side track circuit failure because of a wiring fault, and cancelling an AWS warning but not acting on it - typically overlooking that after passing a long sequence of double yellows, THIS one was a single. However there have been cases where trains have overshot signals because of slippery rails (although I know of no fatalities). You are indeed correct, however I was deliberately being dramatic about the consequences for a reason as Clapham was caused by a track circuit not telling the signalling system it had a train standing on it and at Purley, the driver was unable to stop in time. Both of these can happen through poor railhead conditions and as such it is entirely possible to have a major disaster occur if the appropriate precautions are not taken and reports relating to poor railhead conditions are not acted on immediately - which can mean signifficant disruption for passengers.
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Post by phil on Nov 13, 2015 22:25:50 GMT
Still no reason for Moorgate branch leaves on line. Since the trains mainly run above ground before going on the Moorgate branch, they'll be delayed going onto the branch. The branchline itself probably having some of the best railhead conditions of the whole route! You also need to consider that (1) Leaves can be sucked into the tunnels through the trains slipstream / the vacuum effect behind it. (2) While running on the surface the wheel tread can become contaminated and this contamination can then be carried along and deposited by the train onto the rails well beyond the original contamination site. In the worst case scenario the train itself has to be taken out of service asap and the wheels scrubbed (which may require it to be dragged by a good unit back to the depot for attention). It is important to remember that leaf debris build up is not laughing matter - if it track circuits do not operate correctly or drivers cannot stop in time then I refer you to pictures of Clapham Junction (1987) or Purley in (1989) to see the worst case results.
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Post by phil on Nov 13, 2015 22:20:01 GMT
When I first used the North London line it was served by (elderly) Midland region stock, as historically it was a LNWR service. This presumably explains why it falls in NRs Anglia region, although I am surprised that no one has thought of changing it by now! The reason the NLL falls under the Anglia reason is nothing to do with which company owned it or which regions of BR various bits fell under in the past. Rather it is a case that (1) NRs decisions on routes is based on trying to keep the management of key arteries together. This makes it easier for the engineering departments (e.g. P-Way, S&T, electrification) to plan their work effectively plus it allows the route to feel they have 'ownership' of the assets involved resulting in a better response. (2) Since being resignalled a decade or so ago, most of the signalling has been controlled from a workstation within Upminster IECC which is also responsible for signalling the C2C network. As the box is part of the Anglia route it makes sense to have the NLL also under Anglia*. (3) Putting it under Anglia is a better 'fit' than under say LNW who are going to be far more concerned with the performance of the WCML itself. * This is not unusually, the section from London Bridge to Anerley is part of Kent route not Sussex as control was (until the Thameslink works started) from London Bridge box which is the responsibility of Kent.
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Post by phil on Nov 11, 2015 22:40:22 GMT
Inwards of Basingstoke you start to encounter 455s which are not cheap or easy to convert. Yes the new traction package might be suitable, but the bodyshells were not built for AC conversion in mind Don't be misled by the ac traction package - everything from Networkers on have had ac traction motors, but the traction system still needs a dc supply - even if the external supply is ac you still need to convert from 50Hz to 0Hz (dc) and back again to variable ac. It might be possible to convert the 455s - the 317s and 318s are very similar in most respects except for the presence of a pantograph and transformer. The 465s appear to be very similar to the 365s, which certainly can work on both ac and dc. Anyway - the 455s won't last for ever - they are already over 30 years old. Regarding the 455s - they might be 30 years old but if the leasing company feels its worth fitting them with a brand new traction package then it must think they will be around for quite a while yet - fitting a new traction package isn't cheap! Thing is if they are re-powered, their longevity will then become a case of for how long can the bodyshells be kept going? As for fitting them with AC kit - it all depends on the bodyshell. Just beause the 317s, etc are of the same visual design, it doesn't automatically mean the 455s bodyshell is quick or easy to modify at this late stage in their careers. Turning to the 365 / 465s you need to consider their history. The 465s were designed and ordered by NSE well before anyone had any thoughts of converting 3rd rail to overheads and they were expected to continue trundling around the SE division for the next 40 years just as their slam door predecessors had done. The 365s were ordered 5 years later by the Government to try and tide the York works over in the run up to Privatisation so it was decided to give them the flexibility to be deployed both the GN and SE sections. While they look similar from the outside, the truth is there is not much else that is the same between the two. The 365s simply used the Networker bodyshell to kept the costs down and as such the internals are very different between the two classes - the 465s do not have any passive provision for conversion to 25KV (as is standard for 3rd rail EMUs built today) so they would require a through rebuild to become dual voltage units.
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Post by phil on Nov 11, 2015 20:43:56 GMT
I very much doubt it: the existing DC network mileage is far more extensive than the entire mileage that has been electrified on AC in the past fifty years, and electrifying non-electrified lines is a much higher priority than converting from one system to another. All equipment has a use-by date. If it's cheaper to replace like-for-like then they will. If it's cheaper to convert it, then they will. 3rd rail is non-standard, and that equipment will need to be produced somewhere. The costs came in that Southampton to Basingstoke like-for-like renewals would cost more than converting to OHLE, so that is what is planned. Additonal network costs will be factored in - if the substations around Clapham Junction were to reach expiry next, then I doubt Clapham Junction to Waterloo and Victoria would be up for conversion, but if say the BML south of Haywards Heath were to need major DC renewals, I suspect we would see OHLE put in place instead. You might even see equipment moved - taking the DC equipment from more recent renewals across the network to extend the life of the DC infrastructure in London could well happen. The intended plan after Southampton to Basingstoke was (last I saw), to convert the North Kent lines east of Fareham so that South Eastern's HS1 services would only require OHLE, OHLE to Ore for HS1 services via Ashford, and the conversion of the Oxted lines to South Croydon from DC and Diesel to OHLE. I suspect the BML south of Croydon would probably feature after those. As you say, its not just the electrification kit that you have to consider... With regard to the South Western main line beyond Basingstoke its easy - all electric SWT services are operated by Desiros which only require a pantograph and 25KV transformer fitting (plus a few minor mods) to convert them to dual voltage. Inwards of Basingstoke you start to encounter 455s which are not cheap or easy to convert. Yes the new traction package might be suitable, but the bodyshells were not built for AC conversion in mind plus none of the necessary cabling is there. As a result replacing like for like suddenly looks a lot better than conversion plus a new fleet of trains... The BML is similary easy with regards to outer services (which use Electrostars / Thameslink units) - but runs into problems north of Redhill where 455s start to appear. On SE, it is the Networkers that are an issue - although they are newer than the 455s, they were never built with conversion to AC in mind. Again once you get towards the coast where everything is a Electrostar or a Javalin its not such a problem.
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Post by phil on Nov 8, 2015 19:46:32 GMT
Indeed - but you need to be aware that unless a 'Network Change' procedure* has been gone through, ALL bits of the railway (regardless of whether they have not been used for decades, or have trees growing through them) have to be regarded as operational. As such when it came to TPWS fitment, people looked at the signalling plan , signalling control tables, etc and THAT was what fitment was based on, not usage. As such it is entirely possible for a signal giving exit from a bunch of disused sidings having a high theoretical risk of a SPAD causing a significant incident and the signal be fitted with it accordingly. * This is a rather expensive and drawn out process involving lots of consultation with all TOCs & FOCs who have the power to prevent changes going ahead. The world we live in, eh? Sod, I sound like a grumpy old man Actually the 'Network Change' procedure is there for a good reason - it prevents NR ripping out stuff which the TOCs want to use a few years later. Principally this was to try and prevent the BR practice of ripping stuff out and selling off land which then compromised the viability of new or re-introduced services. Reinstating stuff from scratch is far more expensive than refurbishing what is already there and doing so avoids any issues where the old installation does not meet the design standards for new work.
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Post by phil on Nov 8, 2015 19:33:24 GMT
I see the lengthening work is now well under way at the TFL Rail stations. Looks as if the fast line platforms, not to be served by Crossrail, are also being added to. Is this just a precaution anticipating diversions, or is there any other reason? BTW, is there now actually any good reason to keep the Ilford flyover - at Stratford the original idea of having the cross platform interchange between the Shenfields and Loughtons/Hainaults is now no more valid than it would be with the GEML fasts? Network Rail's maintenance plans for quadruple track routes need to rely on being able to shut 2 put of the 4 lines for engineering work on a regular basis. As such Crossrail trains will be using the fast lines on a regular basis both east and west of London, with a suitable reduction in service to cope. At other times FGW and GA services will be sharing the slow lines with Crossrail - and agin some reduction in service levels should be expected in such a situation.
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Post by phil on Nov 8, 2015 13:28:03 GMT
As everyone suggests though, sending the fast lines under the station and having them emerge in the correct arrangement to eliminate the need for the flyover seems the best plan given how few serve Wimbledon anyway, and you then would actually then have enough surface platforms for the slows and CR2 if you were to also evict Thameslink. That said, I suspect removing the need to terminate at Wimbledon by granting those paths beyond to remove the need two terminal platforms at Wimbledon would prevail as justifying a new tunnel for the Thameslink Sutton loop lines would be quite the ask! The fast line platforms at Wimbledon - while not being used much in normal operations come into their own at times of disruption or engineering work. Given the SWML is a 4 track railway and the desire to not to have bus replacement services, retaining the ability of fast line services to call or terminate there provides essential redundancy on the system, particularly as connections for onward travel via he Overground, District, Thameslink and in future CR2 will be there, plus there is a depot nearby to send defective trains if the need arises. While I can understand the lack of fast line platforms at many stations usually skipped by fast services, having them available at the likes of Vauxhall, New Cross Gate, Norwood Junction, etc is sound and should not be dismissed simply so people can have a slightly quicker connection time. Incidentally one of the reasons that we have cross platform interchange on certain tubes is because a tube is a naturally self contained environment - and as such the complications of inter running carrying out engineering works in close proximity to existing lines, mixing electrification systems doesn't happen below ground.
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Post by phil on Nov 8, 2015 13:08:50 GMT
I always thought it was the Clapton tunnels that made BR go for 6250v AC on the Chenfords, not bridges? Or is this just the other side of the same coin? Same principle and reasoning be it bridge or tunnel though. In the event later research allowed the clearances to be reduced - put it this way there is no way the Thameslink tunnels under London (even with their lowered trackbeds) would be considered suitable for 25KV in the early 1960s - yet by the early 80s such clearances were considered fine for 25KV.
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Post by phil on Nov 8, 2015 13:04:55 GMT
Secondly as regards TPWS (2) Generally TPWS is only fitted to signals where the consequences of a SPAD could be significant.... Generally yes, however there were reports of new TPWS installations at signals where the track had been previously lifted! Apparently one gang were unable to install a TPWS loop until someone with a chainsaw had cut down the tree growing in the four-foot at the intended location of the loop. Indeed - but you need to be aware that unless a 'Network Change' procedure* has been gone through, ALL bits of the railway (regardless of whether they have not been used for decades, or have trees growing through them) have to be regarded as operational. As such when it came to TPWS fitment, people looked at the signalling plan , signalling control tables, etc and THAT was what fitment was based on, not usage. As such it is entirely possible for a signal giving exit from a bunch of disused sidings having a high theoretical risk of a SPAD causing a significant incident and the signal be fitted with it accordingly. * This is a rather expensive and drawn out process involving lots of consultation with all TOCs & FOCs who have the power to prevent changes going ahead.
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Post by phil on Nov 8, 2015 12:53:25 GMT
I also don't know what happens if the system detects the trigger loop is detected before the arming loop NOTHING is the answer - I am aware of at least one trainstop installation where the arming and trigger loops got reversed during a track renewal resulting every train coming into a reversible platform being tripped, while there was no protection to trains leaving the platform. As you say, unlike AWS, TPWS itself is not fail - safe because the loops must be powered to stop the train. However this non-fail safe nature of the equipment is mitigated by a high level of error checking and fault reporting within the TPWS system, combined with fail-safe modifications to the signal control circuitry.
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Post by phil on Nov 8, 2015 12:43:28 GMT
Rather than marker lights showing the direction of travel (surely that's what tail lights are for?), is the marker light not there to aid distance perception? Certainly at night it's easier to tell how far away a car is than a motorbike. Marker (and indeed tail lights) are a hang back from the days of steam where Oil lamps were used, those at the front being switched on to give train information to signalmen in mechanical signalboxes. Over time the need for thios has disappeared and marker lights took on a new meaning - to tell staff which end of the train it was being driven from. As far as visibility to track staff goes - you are not allowed to work closer than 6ft 6* from the nearest running rail during periods of darkness (or during fog / falling snow when viability is reduced such that sufficient sighting distance is not available to the lookout). As such judging the speed of an approaching train is not necessary because you will be in a place if safety to begin with. During the day when lookouts are in use then judging the speed of an approaching train is done primary by the yellow front end getting visibly larger as the train gets closer, plus the distance between the marker lights getting bigger. The headlight in itself does not contribute to this process other than to say "I'm here" (* If the linespeed is less than 40mph the distance drops to 4ft and if the speed of trains is NO MORE than 20mph working with lookouts is permitted)
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Post by phil on Nov 7, 2015 13:04:18 GMT
Even with a 20/20 hindsight mirror, and 100 years later, that's debatable. The LSWR electrified its system much faster than the LBSCR. By the time of the grouping the wires had only reached Crystal Palace, but the live rails had got to Shepperton, Hampton Court and Claygate. Even by 1925 the wires had only reached Coulsdon and Sutton. At that rate, it is most unlikely electric trains would have reached the south coast by 1939, let alone 1932. And given the glacial pace of electrification since 1948, it is quite likely that most of the former Southern Region would still be diesel hauled now - or, more likely, would have suffered the fate of most lines in the south that had not been electrified by the time the Doctor prescribed major surgery to the network. The LB&SCR was not entirely right they chose 6.6 kV AC supply. The other problem with this system was that it came from Allgemeine Elektricitäts Gesellschaft of Berlin, which was a bit of a problem when the Government decided to go to war with Germany! I believe this system requires fewer transformers, and so would be quicker and easier to install once a British company would be found to deliver the electrical equipment.It is not the voltage that is an issue (6.25KV AC was used by BR in the 60s as a way of minimising the amount of bridge works on some newly electrified lines), its frequency. The German system of electrification uses a low frequency of 16.75Hz because it was discovered very early on that DC traction motors would work with this power source*. The LBSCR latched onto this because it made long distance AC electrification viable - while it was readily understood that AC transmission was far more efficient - the only way of converting it was large rotary converters (i.e. turning AC into mechanical movement then generating DC) which wouldn't fit into a train. Hence everyone else (most of whom were only interested in urban electrification to compete with trams) going for DC based schemes which required less expensive electrical equipment that could be sourced from the UK. Yes by the 30s the Southern could have invested in 1500VDC Overheads - but this introduces more complications in having two separate systems to look after. Given the Southern was a private company with shareholders to answer too, introducing a totally new electrification system requiring trains fitted with equipment to cope with both, when the 3rd rail schemes had proved to be very cost effective to date was not going happen. It took until the late 1950s and the introduction of Mercury Arc rectifiers before AC - DC conversion could be undertaken on the train itself. As things stand the German system, while being AC is far from perfect due to its use of a non standard frequency - lines built in the past few decades are at 25KV AC @ 50Hz for this very reason, with most traction built in recent years being similarly equipped. However as with our DC network, the cost of conversion and resulting disruption outweighs the benifits *AC traction motors are difficult beasts to control and they have only become a realistic option thanks to computer control in the past few decades.
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Post by phil on Nov 7, 2015 12:06:42 GMT
Firstly as regards AWS
(1) IT IS NOT FAIL-SAFE, a driver may cancel a 'caution' alert within the perscribed 2 seconds and continue. This is what happened at Purley in 1989 and is why it cannot be compared to L.U. tripcocks (2) It was originality developed as an aid for STEAM LOCOMOTIVE drivers to give them advance warning of the sate of SEMAPHORE DISTANT SIGNALS (see the Harrow & Wealdstone crash of 1952) (3) It is usually installed 200 yards (183m) before (i.e. on the approach to) the signal to which it applies. (4) Where fitted to colour light signals, the signal MUST be able to show a cautionary (i.e. yellow) aspect - AWS is not usually fitted to signals only capable of showing red or green (5) Since the mid 70s (and several nasty crashes) it has been used to alert drivers to significant Permanent Speed Restrictions. (6) Away from lines fitted with 4 rail electrification (i.e. lines used by L.U. it has also been used to give drivers warning of Temporary Speed restrictions (7) It is MANDATORY (and has been for several decades) for all UK mainline traction to have it fitted. Following the Ladbroke Grove disaster it is also a requirement that it MUST be working on ALL passenger trains - if it fails mid journey passengers must be de-trained at the earliest opportunity or a pilot loco with working AWS must be attached.
Secondly as regards TPWS
(1) It is fail-safe in the sense that a driver cannot intervene if the system is activated - they are bought to a stand and must wait 2 minutes before they can move again. Furthermore isolating it can only be done when at a stand. (2) Generally TPWS is only fitted to signals where the consequences of a SPAD could be significant - basically this means signals protecting pointwork and level crossings. Automatic signals are generally not fitted with TPWS. (3) Most signals fitted with TPWS will require one or two Overspeed loops on the approch (depending on linespeed) to signal fitted with TPWS (4) Standalone Overspeed installations can also be used for Permanent speed restrictions. (5) It is MANDATORY for all powered stock to be fitted with TPWS except where alternative protection (e.g. Trainstops on L.U. or the Tyne & Wear system) (6) It is MANDATORY for the TPWS system to be working correctly - of it becomes defective while the train is in service the same rules apply as with AWS.
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Post by phil on Nov 4, 2015 11:45:40 GMT
At Wimbledon the need to turnback will be limited to a small number of services (no more than 8toh in the peaks IIRC) which the SWML cannot accommodate. The figures quoted in the consultatoin are 30tph through the core and 20 tph through Raynes Park, which suggests 10tph turnback - every six minutes. Given the larger size of CR2 trains compared to the Northern Line, if only the turnbackers served Balham this would equate to an increase of capacity at Balham of nearly 50% - surely enough. Bear in mind that many of the people expected to join CR2 at Wimbledon currently use stations at the southern end of the Northern Line, (there are many people living within walking distance of both Wimbledon and Morden, South Wimbledon or Colliers Wood ) and so CR2 will provide some relief to the Northern Line even if it goes nowhere near Tooting or Balham. Maybe - Maybe not, if you have CR2 at Balham then a sizeable number of passengers from Southern services might also transfer. The problem is to find out would delay the whole CR2 process - and have implications for the design stage, much of which is highly advanced. In all this we are perhaps losing site of the reason for going via Balham in the first place is simply that TfLs original routing via Tooting has been found to present significant issues with regard to ground conditions. Personally I feel that going via Tooting or Balham is a mistake - as you say Wimbledon is not exactly hard to get to from South Wimbledon, etc. However TfL have made it clear they want to interchange with the Northern line and out of the two proposals, Balham is I feel a better option, primarily because of the interchange with Southern, which hopefully might reduce the number of 'metro' passengers trying to change at, what is certain to be, a very busy Clapham Junction
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Post by phil on Nov 4, 2015 11:30:11 GMT
Another reason is the potential problems it would cause if either the SWML required a closure for maintenance tasks* - the layout at Abbey Wood was deliberately reconfigured to have CR1 and the Noth Kent line run side by side rather than one inside the other for this very reason allowing maintenance and renewal activities on each line to be undertaken separately, particularly given the different power supply modes (OHLE and Conductor rail impose very different limitations on work sites). Quite. Part of me hopes they will segregate the branches CR2 absorbs and convert them to OHLE. I'm not holding my breath though! I was extremely disappointed about Abbey Wood, actually. Operational convenience ahead of passenger experience it seems. May as well leave the trains in the depot all day so they're never late and minimises wear and tear then. :/ The term 'operational convenience' is a rather glib statement to make - particularly if you have no first hand knowledge of how engineering work is carried out on railway infrastructure. This is particularly true when it comes to electrification as the more intermingled things get, the more expensive it gets to separate out lines for isolation, the more dangerous it gets for staff and the longer it takes to set up and break down possessions. You also need to remember that much engineering work these days requires the use of road railer vesicles - which do foul adjacent lines when they start rotating, plus having a worksite split in 2 by an operational a line is asking for trouble and you need to ask yourself which is worse, someone missing a connection because of the need to use a footbridge or someone being injured or even killed in a possession that is more complex than it needs to be because of design decisions taken in todays environment. There is also the little matter that keeping things as separate as possible makes construction simpler and more effective. What is not generally appreciated is that if works take place away from a operational railway the site falls under building site construction regulations and can therefore use ordinary construction workers. The moment you start doing something on* a railway, all staff need to be certified as competent in Personal Track safety, they need to be looked after by someone holding the railway 'Controller of Site Safety' competence, who in turn has to work under an 'Engineering supervisor', who in turn...... When NR rebuilt the see wall at Dawlish they classed the site as a ordinary construction site - only reverting to a 'railway possession' when it got to the stage of running tamping machines and other engineering trains over the freshly laid track precisely because it made resourcing the work much easier. The situation at Abbey wood is similar thanks to the big fences between what is and what is not a operational railway. Now don't get me wrong I appreciate the benefits of cross platform interchange to users, but there becomes a point when when you factor in the extra building costs / issues it creates, plus the ongoing maintenance headache it would cause for both NR and TfL start mixing two different systems in close proximity belonging to different owners it just isn't sensible.
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Post by phil on Nov 4, 2015 10:56:01 GMT
Finally creating a Balham spur would require a fundamental rethink of a project that is already well on the way to being finalised. Do you terminate at Balham or continue further south to connect to the BML? If so where do you send services to terminate given that unlike the SWML there are no convenient sub end branch lines to take over. Once you start sending CR2 services to the Selhurst / Norwood Junct / Croydon triangle you then hit the problem of all those junctions that need rebuilding - and as with CR1 and Reading**, CR2 then ends up having to contribute to sorting out a mess that is not of its making. There is also a big question over whether linking the BML service patters (which is dominated by having to ensure Thameslink services hit their slots in the core on time) with yet another tightly times cross London service is wise as the repercussions of a delay could extend to half of London if you do. The argument being that if serving Balham/Tooting is solely to relieve the Northern Line, then a turnback spur would achieve this well, and reduce the need for demolition at Wimbledon, and would provide empty trains for passengers to get on, which I suspect would be quite the incentive for getting people to switch. True a Balham / Tooting spur would indeed achieve the goal of providing relief to the Northern line - but it would also reduce the number of trains at Wimbledon. Given part of the rationale is to remove as many SWT services from the existing surface route as possible (within the constraints of them terminating close to London and the branch infrastructure - i.e. level crossings). In the NE things are a bit different, unlike the SWML the NR takeover is focused on only a single service so the New Southgate branch makes good use out of the majority of trains that would otherwise turn short. At Wimbledon the need to turnback will be limited to engineering work on the SWML, Emergency situations, train failures (including DC / AC changeovers) and a small number of services (no more than 8toh in the peaks IIRC) which the SWML cannot accommodate.
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Post by phil on Nov 4, 2015 10:44:03 GMT
One obvious reason is your suggestion makes providing reversing facilities more difficult - having both CR2 platforms side by side allows the provision of a central reversing siding either end of the station (as at West Croydon) plus the easy provision of the necessary crossovers close to the platforms thus minimising the time (and thus the delays to other services) a reversing train blocks the platforms (or their approaches). ...but turnback sidings are irrelevant if indeed they do want 4 platforms. I'd imagine the classic up-PLATFORM-turnback-turback-PLATFORM-down would be used, so all you would need are the crossovers - no sidings. BUT that IS NOT what you outlined in your idea for Wimbledon - there are no easy / quick turnback options with CR2 either side of the SWML
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Post by phil on Nov 3, 2015 10:06:08 GMT
Couple of points that have cropped up elsewhere that might be useful to inject here: The scale of the work at Wimbledon is apparently due to NR denying the paths TfL wanted, so they have to turn back a significant amount of capacity at the end of their infrastructure - i.e. Wimbledon. This means they need 4 platforms rather than 2, and as such the demolition increases massively. Wimbledon will probably end up with 4 through platforms under the bridge given the terminal roads will need to be as long as the through ones. The portal is intended to be north of Wimbledon, with a probable cut 'n cover station box, and a diveunder south of the station to get the up line to the other side of the formation (and to get under the Sutton lines). Why on earth not have separate portals so the up CR2 rises up and takes over platform 5, the up slow shifts across as do the other lines, giving you: Up CR2 UP SLOW PLATFORM Up Slow Up Fast FAST PLATFORM Down Fast Down Slow DOWN SLOW PLATFORM Down CR2 Up Thameslink THAMESLINK PLATFORM Down Thameslink ...though the apparent need for CR2 turnbacks does suggest why this isn't an option. Probably easier to just build 4 tunnels under the current lines and link them with lifts and escalators... Balham's ludicrous diversion. Given the point above, why not serve it on a spur and have CR2 run its tunnels via (and replacing) Earlsfield, and even potentially take some of the BML slow services by having a portal on a Balham spur? One obvious reason is your suggestion makes providing reversing facilities more difficult - having both CR2 platforms side by side allows the provision of a central reversing siding either end of the station (as at West Croydon) plus the easy provision of the necessary crossovers close to the platforms thus minimising the time (and thus the delays to other services) a reversing train blocks the platforms (or their approaches). Another reason is the potential problems it would cause if either the SWML required a closure for maintenance tasks* - the layout at Abbey Wood was deliberately reconfigured to have CR1 and the Noth Kent line run side by side rather than one inside the other for this very reason allowing maintenance and renewal activities on each line to be undertaken separately, particularly given the different power supply modes (OHLE and Conductor rail impose very different limitations on work sites). As for Balham that has only come about because ground conditions along the 'safeguarded' leg via Tooting make construction difficult. Yes I agree, in an ideal world following the SWML and replacing Earlsfield station makes more sense from a 'National Rail' point of view BUT the CR2 project, as with CR1 is very much a TfL one. Hence the focus on keeping these lines as short as possible (the opposite of Thameslink) and the desire to use the Crossrail lines to relieve tube lines wherever possible. This is why we have got he dog leg via Tooting / Balham rather than any significant desire to serve either of these two places specificity at the outset. Finally creating a Balham spur would require a fundamental rethink of a project that is already well on the way to being finalised. Do you terminate at Balham or continue further south to connect to the BML? If so where do you send services to terminate given that unlike the SWML there are no convenient sub end branch lines to take over. Once you start sending CR2 services to the Selhurst / Norwood Junct / Croydon triangle you then hit the problem of all those junctions that need rebuilding - and as with CR1 and Reading**, CR2 then ends up having to contribute to sorting out a mess that is not of its making. There is also a big question over whether linking the BML service patters (which is dominated by having to ensure Thameslink services hit their slots in the core on time) with yet another tightly times cross London service is wise as the repercussions of a delay could extend to half of London if you do. *Note CR2 will be powered by 25KV overheads as far as Wimbledon. ** Note before the GWML electrification was planned, taking CR1 to Reading would have meant CR1 would have had to stump up the cash to replace ALL the signalling from Naidenhead - Reading as the 1960s era kit was not AC traction immune. Hence CR1 were adamant they would not go further than Maidenhead and it wasn't until the GWML electrification had resignalled the Reading area with AC compliment signalling that they changed their mind.
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Post by phil on Nov 2, 2015 2:35:54 GMT
There are several legs in the chain when it comes to train information.
It all starts with the train described at the signal box which is pretty essential to keeping things running in an orderly fashion. Hence if trains are still running to time it's unlikely to be that which is an issue.
Data from the train described is then sent to out to a data hub which the customer information systems and websites like real time trains get their data.
The customer information systems then have to send the info out to the stations, which then have to get the information individual groups of indicators.
All these separate stages are linked by communications links of course - and that is normally where the problem lies, particularly as they are not direct lines and as such they tend to be at the mercy of the likes of BT rather than NRs own telecoms network. Then you have the issue that stations are leased out to TOCs - so a damaged customer information data cable is the responsibility of the TOC to resource and arrange.
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Post by phil on Nov 1, 2015 18:02:07 GMT
The fact that the Crossrail2 consultation envisages the closure of all the LCs on the Lea Valley Line prompted me to think of LCs as they are now. There was one on the Underground till 1994, and there are at least 2 on London Overground, and hundreds throughout the UK. Many are on quiet country roads and lines. Anyone know which is the busiest, in terms of traffic moment - which in the Hixon accident was no of trains per day x no of vehicles/cycles/animals/pedestrians? Is there any theoretical or practical maximum of rail/road user a level crossing can accommodate? Right, firstly from a historical perspective there is no maximum level of trains / vehicles specified for full barrier crossings specified in law, and it is only really since the demise of BR that outside parties have been able to substantially influence proceedings - as the promoters of the BAA airtrack scheme found out any increase over current train frequencies will normally trigger protests from local councils which in this day and age the railway cannot ignore. Secondly as you say there is a set of criteria (including number of tracks, pedestrian volumes, traffic volumes, railway line speed, road speed limit, road user sightliness in the crossing approach, train service frequency, setting (i.e. urban / rural) against which 'Automatic' crossings (ones with half barriers) and 'open' crossings must be assessed. What may be acceptable in rural Lincolnshire on the GE / GN Joint line may not be suitable on a rural crossing over the ECML for example. If substantial changes occur (like a new housing development) it may be that the railway is forced to upgrade the crossing to a 'manned' (CCTV / OD) type (though they can require a developer contribution to the costs of the upgrade).
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Post by phil on Nov 1, 2015 17:44:10 GMT
I don't know the figures, but the three most disruptive in the country are usually cited to be Lincoln High Street and Poole High Street for pedestrians, and for vehicles one on an A2x road in Sussex (can't remember the details) The Sussex one was Beddingham across the A27 outside Lewes. Thanks to the inability of motorists in the busy A27 to obey it, trains were restricted to 20mph in the final few years. One of the reasons it hung on was the endless proposing, then cancelling of the A27 upgrade to duel carriageway between Lewes and Polgate by Central Government. They finally agreed a modest upgrade of the section between Lewes and the turning for Newhaven and the crossing was finally removed 5 years or so ago.
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Post by phil on Oct 31, 2015 18:16:02 GMT
Presumably another plus point for Balham from Crossrails point of view is that there will be less disruption to the northern line. Presumably there may have to be some kind of closure at Tooting/Balham stations for a short while to allow for tunnels to connect - shut Tooting and that area is screwed. Shut Balham and people still have the option of Southern. Saying that if it were to go via Balham, CR2 would basically be duplicating the Southern service between Victoria > Clap Junction and Balham which doesn't seem worth it. I noticed the Dalston area station is called Dalston and its between Dalston Junction and Dalston Kingsland and no doubt will connect with both. Do you think they might just turn all three stations into one with eight platforms? Yes it would be duplicating the Southern service - but the same charge can be made between Wimbledon and Clapham Junction (SWT), Victoria and Euston / Kings Cross (Victoria), Euston - Severn Sisters / Tottenham Hale (Victoria) Stopping at Balham could potentially relieve the Northern line just as well as Tooting, but would also allow passengers from Southern services to change onto CR2 earlier than the overcrowded Victoria and Clapham Junction stops. It would also mean passengers connecting between suburban Southern and SWT services could do so at Balham rather than adding to volumes at Clapham Junction. As regards Dalston - I doubt it would be renamed as a single station, particularly as Dalston Junction and Dalston Kingsland serve different destinations (though they will both serve CR2). Besides we still have the officially separate Bank and Monument stations despite all the connecting corridors below ground, plus Moorgate and Liverpool Street stations (plus the Farringdon and Barblican pairing) will remain separate stations for non CR1 services even though the CR1 station serves them both.
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Post by phil on Oct 31, 2015 3:49:56 GMT
As for Stratford platform 12, I thought that still exists? Maybe the NLL Overgrounds could be extended a little? When at Stratford they point in the 'right' direction! Simon Sorry, my bad, I got my numbers muddled up. I should have said platforms 11 and 12 not 10 and 11 in my previous post. as for extending the Overground platforms - there is the little matter of the case that contains HS1 to consider. Basically if you look at the northern end of platforms 11 and 12 there is no space to use the existing bridge over HS1. From satellite imagery it looks as though it is just about wide enough to extend platforms 11 and 12 northwards (I believe these platforms can only take 8 car EMUs at present) but nothing more.
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Post by phil on Oct 30, 2015 22:59:00 GMT
T = telegraph. It's an old term but it has stuck (read 'communications') - I know 'cause I is one' - part time ! - Got to love heritage railways. Indeed The only involvement S&T have with telecoms are lineside direct dial telephones, the cable that connects them to the nearest location case, plus modems directly connected to signalling equipment. Inter location case lineside cabling, telephone concentrators and suchlike are the responsibility of a dedicated Telecoms department.
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Post by phil on Oct 30, 2015 19:16:35 GMT
In the wrong side failure on the ELL, we are talking about an AWS telling the driver the signal ahead is at green when in actual fact it is at yellow or red, this could in a worst case scenario cause a train to collide with something else (readers may which to search the RAIBs website for a report into an incident at Wooton Basset near Swindon to appreciate the importance of correctly working AWS equipment). Wow, thanks for such a detailed explanation! One thought occurred to me: you've explained all the testing that S&T do on "their" equipment, do similar checks happen to the train involved? I'm thinking things such as an OTMR download. Additionally, would the dataloggers in the 'signalbox' be checked to ensure that the signal wasn't put back in front of the driver (train passes magnet when signal green, but signal put back half a second after so driver looks up to see a yellow)? Yes from the S&T side all relevant logging systems will be examined during the non-distructive testing phase, along with things like train describer data, platform CCTV images and any relevant voice communications between the signaller and the driver. (Note the S&T equipment includes EVERYTHING used in the signalling of trains and includes the signalling panel / workstation in the signal box as well as interlockings and the trackside kit) However it is important to note that logging can only get you so far. In the case of an allegation of a signal displaying the wrong aspect on a SSI area for example, the logger might tell you what aspect the signal was being commanded to show - but it cannot actually confirm what lamp was lit. For that you need a forward facing CCTV image because you MUST NOT discount the possibility of a defect in the cable from the module to the signal head, a wiring issue in the head or a 'great train robbery' style tampering with the aspects has taken place. As a general rule the further up the chain (or the closer to the 'brain') the logging stops the more equipment and cables you have to test - but with relay interlocking there is a limit on just how much you can practically monitor - as it is all retro fitted years after the original signalling was installed. SSI has the logging built in so is easier when it comes to wrong side failure testing but even then it has its limits. It should be noted however that in at least two cases in the past 5 years, the wrong side failure has been traced to a data defect in the SSI interlocking that had somehow got missed when the data was being tested before commissioning and the defect had been there for quite a while - it was simply luck that the particular circumstances that triggered it to show up had not occurred before. As for the OTMR data, this will usually be requested from the TOC as part of the investigation, but the download and interpretation of the data has to be done by the TOC with the results communicated to the S&T level 2 or 3 tester.
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Post by phil on Oct 30, 2015 8:39:33 GMT
The problem is yesterday a driver reported a wrong side failure relating to the AWS for signal number EL262.
A wrong side failure is defined as something that makes the railway more dangerous rather than less.
For example, a track circuit which the signalling system thinks has a train on it, when there is actually is no train there is a 'right side' failure because the signalling system has protected the failure by holding signals at red, preventing points from moving, etc.
Now consider a track circuit which the signalling system thinks is free from trains - yet it actually has a train on it. This is a 'wrong side' failure as the train is not protected by the signalling system - and as Clapham Junction in 1987 proved, death and serious injury are very likely as a result if immediate action is not taken.
In the wrong side failure on the ELL, we are talking about an AWS telling the driver the signal ahead is at green when in actual fact it is at yellow or red, this could in a worst case scenario cause a train to collide with something else (readers may which to search the RAIBs website for a report into an incident at Wooton Basset near Swindon to appreciate the importance of correctly working AWS equipment).
Now while I cannot comment on the specifics of this case (because I don't have all the facts), a guide to 'wrong side' failure testing may bad helpful for forum readers.
Testing in the case of 'wrong side' failures is done in accordance with a strict procedure, designed to pick up ANY flaws in the signalling system. This is laid down in the "Signal Technicians Maintenance Handbook" (SMTH) which gives details of which tests are required and more importantly what level of competence is needed before the piece of equipment against which the allegation has been made can be returned to service.
The actual checks will be carried out by 'level 1' (usually first line S&T response staff) testers with initial checks like wire counting (making sure ALL relevant equipment (which includes the controlling realys, transformers, etc) has the correct number of wires terminated on them), various visual examinations, checks for moisture ingress, doors securely locked, etc. take place with the results accurately recorded - this is known as the 'non destructive testing' phase.
In the 'destructive testing' phase, items of equipment and line side cables are checked for continuity and insulation properties and the presence of spurious voltages that shouldn't be there. In the case of a 48 core lineside cable this may have to take place overnight because of the number of separate bits of signalling equipment that are fed from that one cable. The results from this testing will show whether there is moisture ingress to the equipment, whether there is a short circuit between cable cores or whether a cable core has become connected to earth through damage (ALL signalling circuits MUST be totally independent and NEVER earthed - due to the potential of two earths to cause electricity to by-pass relay contacts and cause a disaster).
The results of both sets of tests are then forwarded up the chain of command to the level 2 tester (usually S&T depot manager level) who reviews the tests and decides whether there is anything more that still needs doing.
However because of the serious nature of 'wrong side' failures, in most cases the SMTH requires the level 2 then has to go up another level to a person with a level 3 (usually area S&T engineer level) compliance who reviews the results and if they are happy it is the level 3 that gives permission for the equipment to be returned to service.
Thus, while I don't have the exact specifics to hand it sounds like because of the wrong side failure allegation yesterday, the capacity of the signalling system was reduced (e.g. A signaller was, say, having to caution every train past the signal before EL262 (because the AWS on EL262 could give a green AWS indication when the signal is actually at red). As a consequence the train service was reduced and amended to make things easier for the signallers and testers.
Now until ALL the evidence has been reviewed and the appropriate level 2 or 3 tester and they are 100% happy with what they have found, the revised service has had to stay in place. It is quite possible that some of the testing could only had done overnight (say a couple of 48 core lineside cables need fully testing affecting multiple signals and track circuits) and not all of it was completed, or alternatively maybe a problem was discovered and a piece of kit needed to be changed (note the decision to do this comes from the level 3), or maybe its a issue between the offical diagrams not agreeing with what is installed on site or situation of simply too much to test and too few qualified staff.
In such situations it's easy to see that the WSF investigation may take some time to complete - however until that investigation is complete and the signalling can be PROVED to be in perfect working order, the equipment the allegation relates to must remain out of service - regardless of how much delay it causes.
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