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Post by jimbo on Jul 29, 2024 0:37:08 GMT
I recall reading somewhere (possibly on this forum) that Metronet were incentivised by the PPP contract to order a very conventional design for the 2009 stock. A walkthrough train at that point would have probably been technologically possible (I don't know about legislation) but reliability would be unproven. I don't think one with walkthrough and]/i] suspended carriages would have been possible then, but I'm far from an expert. The 'Space Train' concept, with smaller bogies, shorter/wider walkthrough carriages, all double doors, and aircon has been talked about since 1995. While the early concepts didn't feature suspended carriages, they did feature carriages sharing bogies. www.railwaygazette.com/metros/space-train-to-boost-tube-capacity/30120.articleJust no-one was willing to take the risk for the 2009 stock, certainly not the sort of thing a PPP company would be willing to do. There must be doubt that the proposed smaller bogies would have worked. Siemens achieves greater headroom throughout the train, including in the gangway connections, which would have been over the bogies on the 'Space Train' concept.
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Post by ted672 on Jul 29, 2024 9:13:15 GMT
Diverging slightly, having looked at the TfL powerpoint from the FoI reply, slide 20 shows a three-car "unit" being transported by road. I wonder if the inner ends of each three-car unit will have some kind of shunt control, or will there never be a need to split trains?
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Chris M
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Post by Chris M on Jul 29, 2024 10:31:31 GMT
Like S stock the trains are a single unit that will only very occasionally be split and never* outside a depot. Providing shunt controls just for these exceptional circumstances would just add expense and complexity for extremely little benefit.
*With the possible exception of during recovery from a major accident.
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Post by jimbo on Jul 29, 2024 11:10:07 GMT
The Victoria Line trains were also built to remain together for life. The problem with splitting a new Picc train into three units is that the even-numbered cars have no wheels, hanging from the odd-numbered cars either side. The middle 3-cars have therefore no wheels on the outer cars, and will need some means of support before the adjacent car can be removed.
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Post by Dstock7080 on Jul 29, 2024 11:55:45 GMT
2009 Stock do of course have UNDM Uncoupling Non-Driving Motor cars in the centre, which can be used for uncoupling in depots, unlike S or 2024 Stock.
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Post by d7666 on Jul 29, 2024 12:49:06 GMT
The coupling to achieve walkthrough carriages was innovative, but now to also to support the weight and stabilise the "unwheeled" carriage is another realm - no wonder the track has to be of a very high standard Mr Gresley managed to do this c1920. Those were conventional gangways not the fully car body width walk through carriages we are talking about here.
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Post by d7666 on Jul 29, 2024 12:54:27 GMT
Slide 14 shows new trains have inter-bogie centre up to 13.6 metres compared to 11.1 metres on current trains, which are already longer than standard due to longer cars. This must be mentioned for track-circuit occupation purposes. To reduce the gap at curved platforms, the pivot point must be at the inter-car connection, also to reduce sideways motion in the gangway. That is where the magic happens! Ideally of course one would like some magic whereby 73TS + track circuits at end of service one day magickally transform to NTFL + no track circuit CBTC in one big bang for start of service the next day so you don't have to worry about track circuit occupation. However I have yet to find a planet with this level of magic. Seriously, w.r.t. track circuits and NTFL, is not an over riding criteria the train length from the very leading axle to the very trailing axle, not the single car inter bogie length ?
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Post by 100andthirty on Jul 29, 2024 14:43:39 GMT
A couple of comments on posts above.
1) The PPP neither encouraged, nor discouraged the space train concept. The solution was left in the hands of bidders. The bidders for the sub surface PPP offered what became S stock from the beginning. The BCV bidder - the same consortium - didn't feel confident to offer the change in train configuration reqired for a fleet that had to be fully in service so soon after the PPP contract was placed. It has taken over 15 years for London Underground, its bidders and now Siemens to explore and evaluate options which have resulted in 2024 tube stock - potential suppliers were brought into LU's thinking in circa 2008/9. 2) Standards and legislation did have an influence on the development of open walk though trains, but these were mainly fire standards. Clearly the vehicles have to be structurally sound
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Tom
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Post by Tom on Jul 29, 2024 20:00:45 GMT
Seriously, w.r.t. track circuits and NTFL, is not an over riding criteria the train length from the very leading axle to the very trailing axle, not the single car inter bogie length ? Both are important. If you were to have a very short track circuit (and we have designed some in very special circumstances in the past - there was a 14m one at White City which consisted of two 7m spurs) the distance between axles becomes critical. In practice this isn't a problem as the usual shortest track circuit is around 30m.
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Post by d7666 on Jul 29, 2024 21:03:06 GMT
Seriously, w.r.t. track circuits and NTFL, is not an over riding criteria the train length from the very leading axle to the very trailing axle, not the single car inter bogie length ? Both are important. If you were to have a very short track circuit (and we have designed some in very special circumstances in the past - there was a 14m one at White City which consisted of two 7m spurs) the distance between axles becomes critical. In practice this isn't a problem as the usual shortest track circuit is around 30m. I didn't know they go that short. Does a coded track circuit really function that short - I mean isn't the train on to the next track before that train has responded ?
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Post by gefw on Jul 30, 2024 7:42:23 GMT
Both are important. If you were to have a very short track circuit (and we have designed some in very special circumstances in the past - there was a 14m one at White City which consisted of two 7m spurs) the distance between axles becomes critical. In practice this isn't a problem as the usual shortest track circuit is around 30m. I didn't know they go that short. Does a coded track circuit really function that short - I mean isn't the train on to the next track before that train has responded ? The issue you quite rightly note is really about system "reaction time" and therefore is as much about train speed (as well as distance). This applies for both track circuit occupancy detection and trainborne systems that use the signal. In the case of the Central line Trainbourne ATP, it reliably detects and responds to Code within a couple of seconds - for "short" signals it is generally better/cleaner/more consistent that this is provided by trackside loops (eg for ATP spots & code loops over Points/crossings). With regards track circuit length - there are many other factors that constrain the practical track length, Tuned areas are problematic with short tracks (below 50m) & the use of insulated block joints for very short tracks is never loved!
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Post by d7666 on Jul 30, 2024 9:26:00 GMT
I did indeed immediately think why not a spot loop than a very short track circuit but then again this lies outside my domain; bit surprised to know of this at White City as I was at Wood Lane for 8 y but on a different part of the whole CL ATO system.
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gefw
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Post by gefw on Jul 30, 2024 14:56:53 GMT
I did indeed immediately think why not a spot loop than a very short track circuit but then again this lies outside my domain; bit surprised to know of this at White City as I was at Wood Lane for 8 y but on a different part of the whole CL ATO system. I to am not aware of the unusual very short track at White City - suspect it came about as part of the new sidings and was necessary due to the compact track layout and needing to achieve adequate segregation of the track circuit frequencies (to minimise feed trough between tracks of same carriers). Ensuring suitable ATP code reception probably achieved using ATP code loops.
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Post by ted672 on Jul 30, 2024 16:56:43 GMT
The problem with splitting a new Picc train into three units is that the even-numbered cars have no wheels, hanging from the odd-numbered cars either side. The middle 3-cars have therefore no wheels on the outer cars, and will need some means of support before the adjacent car can be removed. The photos I saw, and also the info in the FoI response, suggests that the trains will be made up of two three-car sections, the middle car of each three-car unit being supported by the cars either side of it. Splitting into two-car sections seems not to have been part of the plan.
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Post by d7666 on Jul 30, 2024 17:38:56 GMT
The problem with splitting a new Picc train into three units is that the even-numbered cars have no wheels, hanging from the odd-numbered cars either side. The middle 3-cars have therefore no wheels on the outer cars, and will need some means of support before the adjacent car can be removed. The photos I saw, and also the info in the FoI response, suggests that the trains will be made up of two three-car sections, the middle car of each three-car unit being supported by the cars either side of it. Splitting into two-car sections seems not to have been part of the plan. Not sure what you mean As has been said, Picc is 9car total - the middle "3car" needs support If W = wheeled and U = unwheeled 9car = WUWUWUWUW which if you split into 3cars is WUW UWU WUW The FOI has images of a WUW end 3car section .... jimbo is talking about the middle UWU section and how to support the U cars.
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Tom
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Post by Tom on Jul 30, 2024 18:25:06 GMT
I to am not aware of the unusual very short track at White City - suspect it came about as part of the new sidings and was necessary due to the compact track layout and needing to achieve adequate segregation of the track circuit frequencies (to minimise feed trough between tracks of same carriers). Ensuring suitable ATP code reception probably achieved using ATP code loops. Negative; it was a temporary arrangement during the P&C renewal at the West end of the station in 2011. It was only in place for a few weeks, and was carefully positioned so that no train ever ran over it in normal operation! It was a P&C track (which would have required a code loop; I don't think we provided the code loop.
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Post by d7666 on Jul 30, 2024 19:30:05 GMT
carefully positioned so that no train ever ran over it in normal operation! About 42 questions spring to my mind about that. As it was obviously temporary I'll forgo enquiring of the answers.
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Post by jimbo on Jul 30, 2024 20:37:37 GMT
The photos I saw, and also the info in the FoI response, suggests that the trains will be made up of two three-car sections, the middle car of each three-car unit being supported by the cars either side of it. Splitting into two-car sections seems not to have been part of the plan. Not sure what you mean As has been said, Picc is 9car total - the middle "3car" needs support If W = wheeled and U = unwheeled 9car = WUWUWUWUW which if you split into 3cars is WUW UWU WUW The FOI has images of a WUW end 3car section .... jimbo is talking about the middle UWU section and how to support the U cars. Slide 14 shows a complete train with the WUW continuing throughout the train and the bogies only under the W cars. Unfortunately, the raised platform obscures the middle 3-car section to prove the point, but the unwheeled cars are much shorter with no room for two bogies. This does show that the new train requires a long raised platform, not where the current raised section is laid, but overlapping with it. This suggests a programme of raising platforms will be necessary at some time, probably affecting the current raised sections. So when will this be done? When all the old trains have gone, or at the half-way stage? Afterthought: The Picc trains turn on the Heathrow loop, so are the current raised platforms as shown, so only suit half the trains, or are they provided at both ends of the platform? That would mean raising the middle of the platform, together with the current raised sections, would raise most of the length of each platform!
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Post by alpinejohn on Jul 31, 2024 7:12:01 GMT
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Post by brigham on Jul 31, 2024 8:13:44 GMT
What an interesting article, from the engineering point of view.
As regards the previous discussion, this bit is interesting: "Floor height at doorway thresholds will be 700mm which is higher than the standard 520mm platform height".
Trains specifically designed for the Piccadilly line don't fit the platforms. Brilliant.
I wonder if the wheels will be the right distance apart..?
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Post by jimbo on Jul 31, 2024 8:27:28 GMT
The quote is "Floor height at doorway thresholds will be 700mm which is higher than the standard 520mm platform height; LU will be providing ‘humps’ next to designated wheelchair doorways in accordance with usual practice." Trains traditionally ride higher than platforms to allow them to cover the gap at straight platforms. This means a step up to enter, or step down to leave. In recent times LU has provided humps for a short length to achieve level access for those with special needs. This site shows Bakerloo line trains stand 756mm above rail level, whilst the current Piccadilly line trains stand at 730mm. So, the new trains at 700mm are lower than either of those, but still well clear of a 520mm platform. The new humps will provide a longer raised section of platform since the new trains have more provision for wheelchairs along their length.
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Post by ijmad on Jul 31, 2024 11:26:36 GMT
The original video on NTFL foresaw all the platform heights being slightly raised didn't it? Is this no-longer happening or did I misunderstand the meaning of what's going on at 1:40 in the video?
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Post by jimbo on Jul 31, 2024 11:35:40 GMT
That was part of preparation for driverless trains, with platform edge doors. There isn't even money for new signalling on the Picc Line, so that must be far away. Even new trains for the Bakerloo is in the queue for funding before new signalling.
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Post by burkitt on Jul 31, 2024 14:53:17 GMT
As has been said, Picc is 9car total - the middle "3car" needs support If W = wheeled and U = unwheeled 9car = WUWUWUWUW which if you split into 3cars is WUW UWU WUW The FOI has images of a WUW end 3car section .... jimbo is talking about the middle UWU section and how to support the U cars. The 24TS is not composed of three car subunits, or subunits of any other length. It is a single nine car train, alternating between "Key" cars with bogies, and intermediate cars without. The 24TS is never intended to be split up after it leaves the factory. All trains will travel from the factory to London by rail in nine car units. The three car train on a low loader was a one off trip to the climate testing chamber, before that train had been fully assembled.
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Post by d7666 on Jul 31, 2024 17:08:52 GMT
As has been said, Picc is 9car total - the middle "3car" needs support If W = wheeled and U = unwheeled 9car = WUWUWUWUW which if you split into 3cars is WUW UWU WUW The FOI has images of a WUW end 3car section .... jimbo is talking about the middle UWU section and how to support the U cars. The 24TS is not composed of three car subunits, or subunits of any other length. It is a single nine car train, alternating between "Key" cars with bogies, and intermediate cars without. The 24TS is never intended to be split up after it leaves the factory. All trains will travel from the factory to London by rail in nine car units. The three car train on a low loader was a one off trip to the climate testing chamber, before that train had been fully assembled. I never said or implied they are in three sub units or 3car sub units. Suggest need to read further back up the thread. I was replying to a previous poster who stated 3car sub units - I simply used the example that if you do split complete 9car unit into 3 3car sub units the result is the middle 3car has wheelless cars at both ends; my text is an explanation of why that impractical, not a statement that the train is composed of 3csr sub units.
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Post by brigham on Jul 31, 2024 17:58:19 GMT
Delivering railway rolling stock by rail?
How archaic.
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Post by ijmad on Jul 31, 2024 20:13:06 GMT
Will they be dragged through the Channel Tunnel?
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Post by burkitt on Jul 31, 2024 20:22:51 GMT
Yes, they're coming through the tunnel, then onwards to a tube depot entirely by rail. I won't say anymore about the route as they're expected to be a target for vandalism.
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Post by jimbo on Jul 31, 2024 21:59:20 GMT
Do we know how many trains will come from Europe? Is it just the first two pre-production trains? TfL Annual Report says: Around 80 per cent of the trains will be assembled at Siemens brand-new manufacturing site in Goole". Does this mean maybe the first 20 come from Europe? Or perhaps all the car bodies come from Europe, but all are fitted out at Goole, apart from those first two? When is train three expected to appear?
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Post by d7666 on Aug 1, 2024 7:19:03 GMT
Do we know how many trains will come from Europe? Is it just the first two pre-production trains? TfL Annual Report says: Around 80 per cent of the trains will be assembled at Siemens brand-new manufacturing site in Goole". Does this mean maybe the first 20 come from Europe? Or perhaps all the car bodies come from Europe, but all are fitted out at Goole, apart from those first two? When is train three expected to appear? I nearly asked the same question when just a bit upthread the subject of delivery came up. I thought I had read quite recently - within very recent weeks - there had been a change of Siemens' plan and now almost all build would be at Goole not imported - but of course that does not answer proportion of components or sub-assemblies imports as incomplete trains for final assembly here.
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