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Post by norbitonflyer on Nov 1, 2019 21:11:55 GMT
There may well be a phase in which the line is run as two separate sections, with passengers having to interchange between old and new platforms. Crossrail will do this at both Paddington and Liverpool Street. It would allow the extension to be opened without risking any problems being exported to the existing route, and possibly running in new stock whilst the old continues on the existing line. In the long term, of course, the terminal platforms would be redundant.
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Post by jimbo on Nov 1, 2019 23:56:47 GMT
Very interesting thoughts. I can imagine a gap in the westbound service from Lewisham being filled by reversing an eastbound train in the current Elephant platforms. At Lambeth an announcement that the train will terminate at Elephant, and remain on the platform for a Lewisham train. However, no need to clear everyone since at Elephant those remaining can exit by existing connection to Northern line and from there to new exit or new Bakerloo platform interchange, even if current Bakerloo lifts are abandoned and only emergency spiral stairs remain.
Why does this not happen with Jubilee diversions to Charing Cross? Well anyone who recalls that station will remember that it is huge, with big circulation areas and two levels of escalators out to both east and west ends! To maintain all that clean for occasional passengers, and all escalators maintained for restarting with little notice would be expensive. To maintain current Elephant platforms and passages would be a much smaller ask.
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Post by Chris M on Nov 2, 2019 0:11:18 GMT
You've again missed the entire point - they don't show the layout of the passageways at the station, they don't show what the connections between the existing Bakerloo line platforms and any of the new exit, new Bakerloo line platforms or Northern line platforms will be. That level of detailed design simply does not yet exist. Without knowing all of these things we cannot know how practical running the line in two sections will be.
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Post by Chris L on Nov 2, 2019 0:39:02 GMT
You've again missed the entire point - they don't show the layout of the passageways at the station, they don't show what the connections between the existing Bakerloo line platforms and any of the new exit, new Bakerloo line platforms or Northern line platforms will be. That level of detailed design simply does not yet exist. Without knowing all of these things we cannot know how practical running the line in two sections will be. Why would there be any connections between the new and old Bakerloo line platforms? There is no need except in the fantasy world of running new and old trains. The only question is whether there will be escalators and new lifts to/from the Northern line platforms to provide step free access and interchange. One of the first statements in the consultation (which is the subject of this thread) is that there will be new trains and signalling on the whole line. The reason they had to install traditional signalling on the Jubilee line extension was that moving block signalling was in its infancy and proving difficult. It later transpired that a bolt on the track had been driven into a tunnel ring and was causing a short circuit. It was essential to be able to move large numbers of people to and from North Greenwich for New Years Eve 1999. Given that modern signalling is now working on various lines and is being installed on the comparable Northern line extension, there is no reason to expect it not to work from day one on the new alignment.
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Post by ijmad on Nov 2, 2019 2:28:27 GMT
Very interesting thoughts. I can imagine a gap in the westbound service from Lewisham being filled by reversing an eastbound train in the current Elephant platforms. At Lambeth an announcement that the train will terminate at Elephant, and remain on the platform for a Lewisham train. However, no need to clear everyone since at Elephant those remaining can exit by existing connection to Northern line and from there to new exit or new Bakerloo platform interchange, even if current Bakerloo lifts are abandoned and only emergency spiral stairs remain. Why does this not happen with Jubilee diversions to Charing Cross? Well anyone who recalls that station will remember that it is huge, with big circulation areas and two levels of escalators out to both east and west ends! To maintain all that clean for occasional passengers, and all escalators maintained for restarting with little notice would be expensive. To maintain current Elephant platforms and passages would be a much smaller ask. You don't just turn on an escalator from time to time - they need regular maintenance, safety testing, parts have maximum life expectancy, etc. Plus passageways in regular use need cleaning, as do platforms. The cost/benefit ratio is too low to keep Charing Cross open as just a diversionary route. I'd strongly suspect the same would be true of the existing E&C platforms once the extension opens, particularly as they will seem rather far away from anything else, and awkwardly placed, if the surface building closes too.
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Post by norbitonflyer on Nov 2, 2019 7:28:23 GMT
Why would there be any connections between the new and old Bakerloo line platforms? Why would there not? The new platforms would, surely, be designed with connections to the Northern Line. And there is already a connection between the Northern Line platforms and the existing Bakerloo platforms. If, for a short period, the line has to be run in two sections before the final tie-in, it will be possible to walk between them, by way of the Northern Line platforms if necessary. There are several possible reasons why the line might be run in two sections temporarily. For example, the new line being ready but conversion of the signalling on the existing line being delayed, (perhaps because of compatibility problems with NR north of Queens Park), or delays in delivery of new trains meaning there are not enough to cover the entire line. However, once through running starts I can't see maintaining the old platforms happening, on the offchance they might be useful. A reversing crossover on the new alignment would achieve the same result. (or trains could be reversed at Lambeth North using the existing crossover)
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DWS
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Post by DWS on Nov 2, 2019 10:42:06 GMT
Lambeth North has only 2 lifts so reversing the southbound service due to shutdown at Elephant & Castle would lead to overcrowding at Lambeth North.
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Post by norbitonflyer on Nov 2, 2019 11:43:57 GMT
Lambeth North has only 2 lifts so reversing the southbound service due to shutdown at Elephant & Castle would lead to overcrowding at Lambeth North. So you tip out at Waterloo, or make Lambeth North exit only, whilst the problem at E&C is resolved.
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Post by Chris M on Nov 2, 2019 11:50:37 GMT
Why would there be any connections between the new and old Bakerloo line platforms? Why would there not? The new platforms would, surely, be designed with connections to the Northern Line. And there is already a connection between the Northern Line platforms and the existing Bakerloo platforms. If, for a short period, the line has to be run in two sections before the final tie-in, it will be possible to walk between them, by way of the Northern Line platforms if necessary. There are several possible reasons why the line might be run in two sections temporarily. For example, the new line being ready but conversion of the signalling on the existing line being delayed, (perhaps because of compatibility problems with NR north of Queens Park), or delays in delivery of new trains meaning there are not enough to cover the entire line. However, once through running starts I can't see maintaining the old platforms happening, on the offchance they might be useful. A reversing crossover on the new alignment would achieve the same result. (or trains could be reversed at Lambeth North using the existing crossover) Exactly - it's inconceivable that there will be no direct interchange between the Northern line platforms (which are not moving) and the new Bakerloo line platforms. So unless they actively choose to block off the existing connection from the Northern line platforms to the existing Bakerloo line platforms there will be a connection between new and old Bakerloo line platforms. I strongly suspect that long term the existing Bakerloo platforms will be maintained sufficient to be a filming location, run occasional tours to and to be an emergency diversion point should the need arise - i.e. exactly like Charing Cross Jubilee. They might decide that its worth putting in a direct connection to the new station (i.e. other than via the Northern line platforms), they might not - it will all depend on the cost, which in turn depends on the detailed design that hasn't been done yet.
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Post by jimbo on Nov 2, 2019 12:08:17 GMT
New E&C station will likely link with current one for ventilation shaft in current lift shafts at low cost, and maybe emergency access/exit via spiral stairs.
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Post by jimbo on Nov 2, 2019 18:15:41 GMT
Another reason for maintaining connection to the current E&C station is for stabling 3 trains, which extension funding should pay to return to normal usage. The line is very tight for stabling now, and there is no obvious large areas on the extension, so I imagine it will remain tight. Bringing back 3 at E&C is probably the cheapest. How many will fit at Wearside Road Council depot site, Lewisham, remembering that two will become running roads to Hayes, and possibly a reversing road for short workings. The previous consultation said nine trains were needed for Lewisham, so maybe three at E&C and six at Wearside Road.
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Post by ijmad on Nov 2, 2019 20:14:38 GMT
Another reason for maintaining connection to the current E&C station is for stabling 3 trains, which extension funding should pay to return to normal usage. The line is very tight for stabling now, and there is no obvious large areas on the extension, so I imagine it will remain tight. Bringing back 3 at E&C is probably the cheapest. How many will fit at Wearside Road Council depot site, Lewisham, remembering that two will become running roads to Hayes, and possibly a reversing road for short workings. The previous consultation said nine trains were needed for Lewisham, so maybe three at E&C and six at Wearside Road. Presumably you could stable quite a large number trains along the old tunnels if they build the new alignment!
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Post by jimbo on Nov 3, 2019 3:42:58 GMT
Another reason for maintaining connection to the current E&C station is for stabling 3 trains, which extension funding should pay to return to normal usage. The line is very tight for stabling now, and there is no obvious large areas on the extension, so I imagine it will remain tight. Bringing back 3 at E&C is probably the cheapest. How many will fit at Wearside Road Council depot site, Lewisham, remembering that two will become running roads to Hayes, and possibly a reversing road for short workings. The previous consultation said nine trains were needed for Lewisham, so maybe three at E&C and six at Wearside Road. Presumably you could stable quite a large number trains along the old tunnels if they build the new alignment! Maybe six on each line nose-to-tail, but it's not going to happen. Will prevent emergency reversing southbound to north in old station if required. May block other stabled trains if problem with start-up in morning due to technical or staffing problems. Overnight inspection very restricted. Very difficult exit overnight and access on start-up. Involves walking through trains and down to track from cab, back up into next train cab, above current rail! Previous consultation had new stabling like this with four trains on each line south of Lewisham, but new Crossrail size tunnels with walkways, ventilation and access shaft.
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Post by Chris L on Nov 3, 2019 4:56:05 GMT
Presumably you could stable quite a large number trains along the old tunnels if they build the new alignment! Maybe six on each line nose-to-tail, but it's not going to happen. Will prevent emergency reversing southbound to north in old station if required. May block other stabled trains if problem with start-up in morning due to technical or staffing problems. Overnight inspection very restricted. Very difficult exit overnight and access on start-up. Involves walking through trains and down to track from cab, back up into next train cab, above current rail! Previous consultation had new stabling like this with four trains on each line south of Lewisham, but new Crossrail size tunnels with walkways, ventilation and access shaft. They wouldn't be Crossrail size for large trains and overhead power supplies. Bakerloo line trains are a lot smaller. The new tunnels will have walkways.
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Post by jimbo on Nov 3, 2019 6:48:19 GMT
Maybe six on each line nose-to-tail, but it's not going to happen. Will prevent emergency reversing southbound to north in old station if required. May block other stabled trains if problem with start-up in morning due to technical or staffing problems. Overnight inspection very restricted. Very difficult exit overnight and access on start-up. Involves walking through trains and down to track from cab, back up into next train cab, above current rail! Previous consultation had new stabling like this with four trains on each line south of Lewisham, but new Crossrail size tunnels with walkways, ventilation and access shaft. They wouldn't be Crossrail size for large trains and overhead power supplies. Bakerloo line trains are a lot smaller. The new tunnels will have walkways. The Battersea tunnels are about Crossrail size! Why not the Bakerloo? To be circular and wide enough, they end up high.
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Post by alpinejohn on Nov 3, 2019 9:46:33 GMT
I assume Health and Safety considerations will mean the new tunnels will have to incorporate some sort of emergency exit walkway system - much as they insisted for the Jubilee extension route. That suggests the tunnel diameter will be a bit bigger that the original Bakerloo tunnel diameters.
If/when this project goes out to tender, then the tender will doubtless specify minimum internal dimensions. Potential bidders will then consider whether their quotation should reflect the purchase of new TBMs(tunnel Boring Machines) or if any kit they already own might be re-used to make their quotation for the Bakerloo extension more competitive.
Obviously there is a trade off. If you go larger than strictly dictated by the customer specification, you have more material to excavate and dispose of.
It seems weird that since expensive monster tunnelling machines became the norm for most larger tunnel projects, relatively few have been re-used. Obviously the pioneers may have revealed plenty of areas where subsequent tunnelling machines could be made far more efficient and reliable. However given how many TBMs have now been made around the world, I suspect most of the bugs will have been worked out by now and that much of the kit used so recently to dig the Crossrail tunnels was not totally dilapidated when the tunnelling phase was completed and simply put in store somewhere.
The sad fact remains TFL will probably end up paying out yet again for new TBMs to build the Bakerloo extension and yet again for Crossrail2 if that ever goes ahead.
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rincew1nd
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Post by rincew1nd on Nov 3, 2019 10:31:12 GMT
AIUI, Tunnel Boring Machines (TBMs) are often bespoke designs to match the anticipated ground conditions, so finding the right TBM for the job can be difficult if you're looking to buy "pre-owned". There's also the factor to consider that on some occasions any re-sale/scrap value may be less than the cost of extracting the TBM from the end of it's dig; the British TBMs that dug the Chunnel remain beneath the waves (and indeed the rails) of the English Channel where they are currently providing a rather good electrical earth.
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Post by jimbo on Nov 3, 2019 11:31:57 GMT
I assume Health and Safety considerations will mean the new tunnels will have to incorporate some sort of emergency exit walkway system - much as they insisted for the Jubilee extension route. That suggests the tunnel diameter will be a bit bigger that the original Bakerloo tunnel diameters ..... I believe the Jubilee solution was no longer considered acceptable by the time Crossrail and Battersea were planned, requiring larger diameter tunnels. I recall the Battersea tunnels' external diameter is approx. Crossrail internal diameter.
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Post by phil on Nov 3, 2019 20:21:18 GMT
It seems weird that since expensive monster tunnelling machines became the norm for most larger tunnel projects, relatively few have been re-used. Actually most have been!
What you need to remember is that most of the cost of TBMs is NOT the cutting head - its the sophisticated 'train' of spoil handling / segment installation, etc equipment which follows on behind.
One a TBM has completed its run, most of this expensive kit is refurnished then reused - particularly as in most cases the end of the tunnelling will be in a station box, a vent shaft where the tunnel surfaces allowing easy access for dismantling.
The channel tunnel example given above is actually very much the exception rather than he rule - and even here, much of the backroom kit was removed for reuse - what was left was basically a metal shell and worn cutting head.
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Post by Chris M on Nov 3, 2019 20:29:35 GMT
It's worth remembering that the cutting heads frequently require maintenance and repair, including replacement parts, en route. Think of them like drill bits in an electric drill.
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Post by phil on Nov 3, 2019 22:22:42 GMT
It's worth remembering that the cutting heads frequently require maintenance and repair, including replacement parts, en route. Think of them like drill bits in an electric drill.
While this is indeed true, the cutting heads on a TBM are classed as 'consumables' - just a the individual bis householder or builder might put in their latest Makita / De-walt / power tool.
Just as a householder / builder doesn't throw away the power tool after each individual job, the same is true of TBMs - many of the parts / systems which go into the 'train' behind the cutting heads will be good for multiple tunnelling jobs.
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Post by jimbo on Nov 3, 2019 23:32:29 GMT
I assume Health and Safety considerations will mean the new tunnels will have to incorporate some sort of emergency exit walkway system - much as they insisted for the Jubilee extension route. That suggests the tunnel diameter will be a bit bigger that the original Bakerloo tunnel diameters ..... I believe the Jubilee solution was no longer considered acceptable by the time Crossrail and Battersea were planned, requiring larger diameter tunnels. I recall the Battersea tunnels' external diameter is approx. Crossrail internal diameter. A quick Google, so no guarantee, but legacy tube tunnels 3.6m. Victoria line 3.85, Jubilee extension 4.35m. Battersea 5.2m (same as DLR!), so probably Lewisham extension also! Crossrail 6.2 internal in 7.1 metre bore. QED.
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Post by scheduler on Nov 13, 2019 1:06:11 GMT
There won't be any Platform Edge Doors, they are a nuisance on the Jub. The Bakerloo is definitely ahead of Central for new rolling stock - no both lines at the same time. No old trains down the new tracks. It has to be new fleet, then open the extension, then re-signal rest of line, then run whole line as automated at least as far as north as Queens Park. Number of trains - currently 31 required for peak service. Proposed 27tph suggests an extra 9 required for existing route, extension probably 9 more on top of that - suggests a required new fleet size of about 50 trains. Potentially the last batch for the extension, or for the frequency boost, whichever comes second, could be done later, as I think the plan is for the Picc, Bakerloo and Central to all get the same type of trains. So barring - minor tweeks between lines in terms of number of cars in the full unit, I expect they will stick with that plan - cheaper that way!
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Post by countryman on Nov 13, 2019 8:46:11 GMT
I believe the Jubilee solution was no longer considered acceptable by the time Crossrail and Battersea were planned, requiring larger diameter tunnels. I recall the Battersea tunnels' external diameter is approx. Crossrail internal diameter. A quick Google, so no guarantee, but legacy tube tunnels 3.6m. Victoria line 3.85, Jubilee extension 4.35m. Battersea 5.2m (same as DLR!), so probably Lewisham extension also! Crossrail 6.2 internal in 7.1 metre bore. QED. My understanding is that the Central line tunnels are slightly smaller than the other tube lines, requiring a slightly different positioning of the outside power rail, and has, in the past, caused issues with the shoegear.
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DWS
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Post by DWS on Nov 13, 2019 9:43:29 GMT
A quick Google, so no guarantee, but legacy tube tunnels 3.6m. Victoria line 3.85, Jubilee extension 4.35m. Battersea 5.2m (same as DLR!), so probably Lewisham extension also! Crossrail 6.2 internal in 7.1 metre bore. QED. My understanding is that the Central line tunnels are slightly smaller than the other tube lines, requiring a slightly different positioning of the outside power rail, and has, in the past, caused issues with the shoegear. The central line tunnels east of Liverpool Street were built to a standard bigger than the section of the Central London Railway which ran between Wood Lane to Bank - Liverpool Street.
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Post by Chris M on Nov 13, 2019 9:43:56 GMT
The Central line tunnels do have a different position of the positive rail, and so require trains with "high lift" shoe gear. this old thread and parts of the RM web post from 2011 that google finds with "high-lift shoe gear" suggest (but don't make explicit) that modern designs of shoe gear are (as a side-effect of the design) compatible with this higher current rail. If the intention is to run a common fleet of trains then I'm sure that being able to run on the Central line will be a requirement for all the trains. (This is getting away from the topic of the Bakerloo line extension though).
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Post by MoreToJack on Nov 13, 2019 11:32:42 GMT
There won't be any Platform Edge Doors, they are a nuisance on the Jub. The Bakerloo is definitely ahead of Central for new rolling stock - no both lines at the same time. No old trains down the new tracks. It has to be new fleet, then open the extension, then re-signal rest of line, then run whole line as automated at least as far as north as Queens Park. Number of trains - currently 31 required for peak service. Proposed 27tph suggests an extra 9 required for existing route, extension probably 9 more on top of that - suggests a required new fleet size of about 50 trains. Potentially the last batch for the extension, or for the frequency boost, whichever comes second, could be done later, as I think the plan is for the Picc, Bakerloo and Central to all get the same type of trains. So barring - minor tweeks between lines in terms of number of cars in the full unit, I expect they will stick with that plan - cheaper that way! Please, please, please just stop with the utter nonsense. Time and again you post things that are at best misguided and at worse is complete fiction. Your knowledge of the operational railway is weak, and it shows. -PEDs will without doubt feature at any sub surface stations -Central is before Bakerloo. It does keep changing, and it is unlikely there will be a joint replacement, but there’s no ‘definitely’. -There is no practical reason why there can’t be a phased introduction with only new trains permitted on the extension and old stock confined elsewhere. It is technically possible, has happened before with different signalling (Victoria like) and isn’t a particularly huge leap. It will all come down to the timings (I agree that it is unlikely however) -Whole line resignalling will happen but will be phased as with any system. 4LM will have proven ATO is possible on shared sections so there is no reason it can’t just be as far as Queen’s Park. But it would also be unlikely the extension would be signalled conventionally and then resignalled, as implied by your post... There’s so much ridiculous hyperbole here, but then there always is with your posts.
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Post by ijmad on Nov 13, 2019 15:48:47 GMT
I have travelled on the Jubilee Line practically every week for the last 6 years and I've seen a total of one single PED failure in that time (which I was able to pull open manually from inside the train using a handle).
I am not sure who thinks they're a nuisance.
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Post by Chris M on Nov 13, 2019 17:07:44 GMT
I've travelled on the Jubilee line at least once a week most weeks since mid 2010 (although with a gap in 2013-14) and from memory I've experienced two occasions where the PED had to be released manually (Westminster westbound was the first, I can't remember where the second one was but someone else did the honours that time), one occasion were there was a failure that prevented one set of double doors opening (Canary Wharf eastbound, a CSA was stationed on the platform pointing people to the doors either side) and one occasion where a failure a station had to be non-stopped because of faulty PEDs (Bermondsey, but I forget which direction).
I think the perception that PEDs are a nuisance comes from reading failure logs without understanding context. On a station with peds they are often the single largest cause of delays, but what these stats don't show is that those stations don't have delays from people or object on the track (or people dangerously close to the platform edge) which are typically both more common and longer-lasting than PED issues.
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Post by towerman on Nov 15, 2019 13:22:57 GMT
Re the problem of stabling the additional stock,there used to be a carriage repair shop on the BR land next to Stonebridge Pk Depot.Is that land still available or has it been built on?
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