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Post by toby on May 6, 2017 12:33:59 GMT
Best practises of the day. T5 also has only opened half the station. i haven't been, so I'm not sure if Carto Metro is showing all of it or just the opened part.
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Chris M
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Post by Chris M on May 6, 2017 12:58:02 GMT
Carto Metro shows the open 2/3rds of Heathrow Terminal 5 station.
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Post by Deep Level on May 6, 2017 14:24:50 GMT
I never understood why the didn't get rid of the loop and run all services via T2&3 terminating at both T5 and T4 just like the National Rail track arrangement.
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Post by Chris M on May 6, 2017 14:35:41 GMT
This would require a reversing move at T4 (which would reduce the recovery time available), and would result in longer journey times to T4 (T123 is two minutes further away from T4 than Hatton Cross is from T4; plus dwell time at T123). I also suspect that it would require modification to the signalling as the loop was never intended to be used anti-clockwise.
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Post by nig on May 6, 2017 15:36:52 GMT
Plus t4 is a single track so wouldn't be able to run as many trains as the dual t5 track
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Post by norbitonflyer on May 6, 2017 15:42:05 GMT
As the Loop is single track, and T4 to T1123 takes 5 minutes, you would also be limited to one train every 10 minutes (longer in practice, as you would need some dwell time at the terminus at T4)
In fact, if T5 could cope with the numbers of trains, it would be better to run all Piccadilly trains to T5, and rely on the much shorter HEx shuttle to connect to and from T4. Unfortunately the interchange at T123 is not ideal for this.
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Post by nig on May 6, 2017 15:50:01 GMT
In fact, if T5 could cope with the numbers of trains, it would be better to run all Piccadilly trains to T5, and rely on the much shorter HEx shuttle to connect to and from T4. Unfortunately the interchange at T123 is not ideal for this. Why as it's quicker and no changing of trains at moment to get to t4 than 12and 3 plus carry all bags and change to shuttle why would you want to stop all pic line trains running to t4 ?
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North End
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Post by North End on May 6, 2017 15:54:06 GMT
I never understood why the didn't get rid of the loop and run all services via T2&3 terminating at both T5 and T4 just like the National Rail track arrangement. It could be run this way, but: 1) By the time you allow for 6 mins running time each way and minimum 4 mins turnaround time, you're looking at one train every 20 mins. This would actually probably cater for T4 traffic levels, but does it represent an improvement over today? 2) More resignalling would have been necessary compared to the chosen solution. 3) You have a problem that if a T4 train were to turn up at T123 while another is on the branch, it is now blocking the T5 route with nowhere else to wait out of the way. There is of course the option to divert such a train to T5 but again this is not good for the passengers wanting to get to T4. LU did actually consider a shuttle service for T4, but it never happened. One single double-ended unit going up and down between Hatton Cross and T4 might very well have worked but for the time needed to reverse at Hatton Cross in the middle of the 5-min T5 service. A separate Northfields-T4 service might also have worked, but then you may as well join with the Northfields to Arnos trips. The current setup is messy, but unfortunately is probably the best of a bad job. Heathrow could do with a better frequency - today's service is less frequent than 20 years ago - but Crossrail should provide relief soon enough. As long as Crossrail doesn't end up with a heavy Heathrow premium fare that is...
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Post by waysider on May 6, 2017 18:03:38 GMT
Thanks to everyone for shedding light on that
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Post by norbitonflyer on May 6, 2017 18:56:40 GMT
In fact, if T5 could cope with the numbers of trains, it would be better to run all Piccadilly trains to T5, and rely on the much shorter HEx shuttle to connect to and from T4. Why as it's quicker and no changing of trains at moment to get to t4 than 12and 3? Better than running to T4 from T123 as a single track branch, I meant
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Post by Deleted on May 7, 2017 12:28:36 GMT
Has/ was there any consideration for linking in the new terminal to the tube line?
I see that the 'master plan' shows a rail link from the new terminal to T5?
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Post by alpinejohn on May 17, 2017 6:40:55 GMT
Has/ was there any consideration for linking in the new terminal to the tube line? I see that the 'master plan' shows a rail link from the new terminal to T5? Simon11 – As others have not responded – I think the short answer to your question is of course yes. However when it comes to large infrastructure developments and Britain’s planning system – the eventual outcome may seem far from planned. The future shape of Heathrow probably ranks among the most murky destinies, which seems unlikely to become crystal clear anytime soon. It would be a brave Heathrow executive who would “at this stage” commit to invest heavily in passive provision for transport infrastructure for the airport expansion plans, except as part of a fully “planning approved” and unavoidable project. This is of course exactly what happened when Heathrow committed to build the Terminal 5 complex (which is in fact T5a, T5b and T5c) but they are all served by the single (T5 aka Heathrow West) station. If you look closely at the master-plan you can see there was extensive rail platform provision within the sub-basement of T5. Indeed I think there are still a couple of unused platforms and space for potential lift/escalator shafts lurking below T5 which could be brought into use at some future stage if required. Despite the recent third runway Government endorsement, the prospect of legal challenges and planning process delays which may change or completely frustrate the airport expansion plans does not provide the ideal backdrop for any pre-emptive transport planning or provision. What seems clear, is that if/when, the third runway does actually happen, there will also be a need for a new terminal (T6 aka Heathrow North) [and rail-links] primarily to serve the new runway. Logically this terminal would be located “somewhere north of the existing northern runway” to avoid planes having to taxi across the existing northern runway to reach the existing terminals and in the process significantly reduce that runway capacity. However the exact position of the additional runway is far from fixed, and until that is nailed down, apart from some Crayonista drawings it is probably too early to invest in pouring concrete for any possible terminal.
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Ben
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Post by Ben on May 17, 2017 11:11:14 GMT
I seem to recall there was some consideration within TfL for a projection from one of the Heathrow stations to a station on the GWR mainline. Given the upcoming western access link from Iver for XR, this is no doubt dead, but depending on how awkward any R3/T6,7,8 connexion is (probably very given the Pic is E-W but the terminals arent) it might rear its head again.
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Post by toby on May 18, 2017 8:56:14 GMT
I read somewhere, probably here, that they can't tunnel under an active runway. Was the north runway closed while they made the main line tunnel?
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Post by Chris M on May 18, 2017 9:14:11 GMT
I read that here as well, but I can't find any reliable sources to back it up. Obviously you can't built a cut-and-cover tunnel but a bored tunnel should be no problem, and Heathrow runs so close to capacity as it is that you can't just close one of the runways for any length of time.
The only things I'm seeing are that it will be cheaper to build the third runway above the M25 rather than put the M25 in a tunnel below it.
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Post by crusty54 on May 18, 2017 10:14:55 GMT
I seem to recall there was some consideration within TfL for a projection from one of the Heathrow stations to a station on the GWR mainline. Given the upcoming western access link from Iver for XR, this is no doubt dead, but depending on how awkward any R3/T6,7,8 connexion is (probably very given the Pic is E-W but the terminals arent) it might rear its head again. Network Rail are proposing a link from Staines into Terminal 5
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Post by Deleted on May 18, 2017 14:09:26 GMT
The underlying geology in the Heathrow area includes gravel beds, which are not good for tunneling through. I think I remember an incident in the construction of one of the tunnels (either the Terminal 4 loop or Heathrow Express) where an airport building was undermined causing structural damage.
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Post by littlejohn on May 18, 2017 14:15:06 GMT
Wasn't this to do with the sprayed concrete tunnel lining going wrong?
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Post by norbitonflyer on May 18, 2017 16:53:25 GMT
I think I remember an incident in the construction of one of the tunnels (either the Terminal 4 loop or Heathrow Express) where an airport building was undermined causing structural damage. You remember correctly. It was the HEx construction and, amusingly, the building in question was being used as a site office for the HEx project management team.
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Post by crusty54 on May 18, 2017 17:16:22 GMT
It was called the New Austrian Tunnelling Method.
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Post by alpinejohn on May 18, 2017 20:44:50 GMT
I read that here as well, but I can't find any reliable sources to back it up. Obviously you can't built a cut-and-cover tunnel but a bored tunnel should be no problem, and Heathrow runs so close to capacity as it is that you can't just close one of the runways for any length of time. The only things I'm seeing are that it will be cheaper to build the third runway above the M25 rather than put the M25 in a tunnel below it. Chris is right and I suspect I might have been the one to red flag the idea of just sending a TBM under an "active runway" to permit a more convenient railway infrastructure alignment. Inherently any major airport owner will think long and hard about risk, impact, probability and insurance. Concerns which are greatly exacerbated in an airport like Heathrow where there is no slack capacity to permit any extended runway closure should the tunnelling project not go according to plan. The potential consequential costs would be immense if the TBM failed or encountered poor ground and ended up stuck beneath the runway forcing an extended runway closure - so much so, it rather makes the idea pretty much a non-starter - at least until an additional runway became available. To put things in perspective typically there is one major tunnelling incident every year (OK some years none then others can have four) but without digging out dusty text books, I recall a study showing insurers paid out well over half a billion to cover 18? significant tunnelling incidents between 1994 and 2005. These covered a whole heap of different tunnelling systems - Ground freeze, NATM(New Austrian Tunnelling Method), TBM(Tunnel Boring Machine, C&C(Cut & cover) and a heap of different causes including at least one serious incident caused by an earthquake! As for the third runway location the core idea is it would be on an east west alignment to the north of the current Northern Runway. I suspect they will however try to keep the runway as far to the east as possible to avoid actually extending the runway directly over the M25 - although an overbridge taxiway might be possible - the sight of a plane trundling overhead may be somewhat distracting to motorists. Whilst the M25 to the west of the airport is partially in cutting, it is already a very wide and very busy road - ranging between 4 lanes each way to almost 8 lanes each way, once you add in the slip roads and brake down lanes. Even with a massive central pier the cost of building a structure strong enough to span the full width of the motorway and withstand the stress loads associated with an "active runway" would be enormous. It is not just the sheer weight of a bridge structure needed to support a plane like the A380, an active runway also has to withstand potential point load impacts and the transmitted energy of a A380 landing and then braking on a runway. Heading swiftly back to topic this all suggests that as and when the new T6 location is fixed, the tube and rail services will probably approach it from the west. In essence the rail services will be extended in a graceful u turn around from the existing T5 platforms - where the Tube and National rail platforms already have passive provision to extend westwards.
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rincew1nd
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Post by rincew1nd on May 18, 2017 20:59:44 GMT
As for the third runway location the core idea is it would be on an east west alignment to the north of the current Northern Runway. I suspect they will however try to keep the runway as far to the east as possible to avoid actually extending the runway directly over the M25 - although an overbridge taxiway might be possible - the sight of a plane trundling overhead may be somewhat distracting to motorists. Leeds-Bradford has a runway-end/taxiway over a dual carriageway. The southern runway at Manchester was built over a dual-carriageway. The only significant accident I'm aware of in Manchester was a waggon catching fire in the tunnel. At Leeds-Bradford a plane ran out of runway on at least one occasion. AIUI there haven't been any accidents caused by drivers or pilots being distracted by each other.
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Post by Chris M on May 18, 2017 23:16:21 GMT
I can't immediately find it again but one of the articles on the BBC News website mentioned that because of sight lines, etc drivers on major roads under runways/taxiways don't really see much of planes.
It's not like the old arrangement at Bristol Airport where they closed the A38 every time a plane took off eastwards or landed in either direction (eastbound landings in case of overrun, westbound landings as high sided vehicles were potentially in the way of wheels and all vehicles were at risk from turbulence).
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Post by John Tuthill on May 19, 2017 7:07:15 GMT
I can't immediately find it again but one of the articles on the BBC News website mentioned that because of sight lines, etc drivers on major roads under runways/taxiways don't really see much of planes. It's not like the old arrangement at Bristol Airport where they closed the A38 every time a plane took off eastwards or landed in either direction (eastbound landings in case of overrun, westbound landings as high sided vehicles were potentially in the way of wheels and all vehicles were at risk from turbulence). Wasn't there a similar operation at Northolt? Wan't West End Road closed for a similar scenario?
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Post by Dstock7080 on May 19, 2017 9:24:30 GMT
Wasn't there a similar operation at Northolt? Wan't West End Road closed for a similar scenario? Still happens for most aircraft movements over West End Road.
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Post by John Tuthill on May 19, 2017 9:57:58 GMT
Wasn't there a similar operation at Northolt? Wan't West End Road closed for a similar scenario? Still happens for most aircraft movements over West End Road. Thanks for that
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Post by littlejohn on May 19, 2017 15:44:24 GMT
My last posting before I retired from the RAF after 39 years was to Northolt. There is a set of traffic lights on West End Road which, if I recall correctly, were activated by Air Traffic Control. Certainly an unusual occurrence although not unique (I think also at RAF Gibraltar). I also recall back in the 50s that the A30 was regularly closed at Blackbushe so that planes could be towed from one side of the airport to the other.
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Post by norbitonflyer on May 19, 2017 16:22:54 GMT
Northolt. There was a set of traffic lights on West End Road . The lights are still thereThe aerial view shows a house-free zone across the road from the runway end, presumably as an over-run area - - not sure a petrol station is the ideal establishment to have so close to the over-run area though! RAF Waddington has a similar arrangement on the A15 for the AWACs planes
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Post by John Tuthill on May 19, 2017 16:34:54 GMT
My last posting before I retired from the RAF after 39 years was to Northolt. There is a set of traffic lights on West End Road which, if I recall correctly, were activated by Air Traffic Control. Certainly an unusual occurrence although not unique (I think also at RAF Gibraltar). I also recall back in the 50s that the A30 was regularly closed at Blackbushe so that planes could be towed from one side of the airport to the other. Can you confirm that in the 60s a 707 landed there by mistake? I seem to recall they had to strip it out, chopped down some of the trees in West End Road,lined it up at the extreme end of the runway with just enough fuel to reach LHR. Can't remember if it was Pan Am or PIA
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Post by whistlekiller2000 on May 19, 2017 16:38:39 GMT
Northolt. There was a set of traffic lights on West End Road . The lights are still thereThe aerial view shows a house-free zone across the road from the runway end, presumably as an over-run area - - not sure a petrol station is the ideal establishment to have so close to the over-run area though! RAF Waddington has a similar arrangement on the A15 for the AWACs planes I've watched quite a few AWACS (and some special guest planes from abroad) land there while stuck at the lights over the years. Quite exhilarating. I think they had/have a similar arrangement at Humberside Airport although I maybe mistaken.
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