Probably hardly at all. The alignment is already determined so there's no opportunity to make it any less (or more) straight, and I can't imagine there's much saving in track or signalling when comparing passenger at 90mph with heavy freight at a lower speed.
The whole line has to be put back in at some point or no one is doing engineering works south of Aylesbury. Latest plan is leaving it as 30 to Quainton with some (five) of the planned signals removed, basically meaning Aylesbury VP to Greatmoor as absolute block and the rebuilt section north of there to Greatmoor onwards is at 90mph with all the signaling.
If it's being rebuilt, surely it'll be Track Circuit Block, just planned as AB for headways?
Where are the Calvert trains going from FCC if we block south of Aylesbury? their new facility greatly increases their ability to run trains and are expecting an uplift, which will include weekend runs.
This. It will be TCB controlled from Rugby ROC from about the 41 mile post. MC303 will be the start of the section at AVP, AC2407 the distant before Greatmoor with AC2409 the next section prior to Greatmoor South Jn.
MP 41 had me foxed until I checked Trackmaps - that's the distance from Baker St via the Met!
I'm having difficulty visualising this - are you saying that each track from north to south is further underground, to the extent that there is a full platform height's worth of difference between the first and last ones?
I assumed he was referring to the Up Relief line of the GWML on the surface being above the HS2 platforms in the below-ground OOC station
No, he's saying the Up GWML Relief Loop platform at surface level will be vertically above the Down HS2 Loop platform.
Is the conveyor system importing supplies and exporting spoil to/from Willesden Euroterminal now in operation?
It should be as trains are running from there to Barrington.
That's correct
Until the capping beams, cross beams etc are done which is dependant on the utility bridge being done, full scale excavation cannot start.
NB. There are two Relief Line loops - the Down Relief Loop (Platform 6) and Up Relief Loop (Platform 7).
I may have got the terminology imprecise, as I haven't seen engineering plans. My understanding was that it would be very similar (or identical) to the Reading setup. Down Main on 1/2, Up Main on 3/4, Down Relief on 5/6 and Up Relief on 7/8 (or numbers inverted, depends). No idea if loops would be inside or outside each line.
The diagram I've got (dated 2012, so might be out of date) shows the HS2 station with 3 island platforms, each with 2 faces.
Cheers
Here’s a reasonable 2016 drawing of the area under discussion, it does look as though it’s only GW tracks that are aligned over the HS2 box, rather than a platform. The intersection point is quite close to the end of the up relief platform though, as noted by @WiredUp a few posts back:
HS2 has 6 platforms, consisting of 3 sets of island platforms: P9 - P14
Second sequence appears to be from that viaduct over the tunnel segment casting yard towards the southern Chiltern Tunnel portals.
The relevant route plan does show significant landscaping in that specific area, you can find a map here, it’s the bright green bit: https://assets.publishing.service.g...ile/529506/C222-ATK-CV-DPP-020-000001-FPD.pdf
I like the "Passive provision for the Heathrow Spur" note in the middle of all that green!
Yes I noticed that, I don’t suppose anything special will be built though, even if they might retain the wider area in rail ownership?
It looks like it just includes a wide embankment so that there's room for a flyover line if it ever comes back.