NR-owned track is only signed off for up to 125mph in general, so there would have to be a re-evaluation of whether the track is capable of faster operation. But then there'd still be the thorny issue of pathing and timetabling - at 125mph there is already a differential with 100mph Heathrow Express services, and though with the 378s I'd have thought that becomes 110mph, it goes from being a 25mph differential to a 30mph differential.
I understand that ETCS on the lines out of Paddington is an overlay system, where the ETCS is added onto the existing signalling, not replacing it.
Why not cl.800s all round?
I suspect the time for the two classes to traverse that 12 mile stretch from a standing start to the airport divergence will be very close indeed. The 387 might be a bit more sprightly in the lower speed ranges so can get ahead. Just as the heavier 80x catches up, the 387 dives off the main to the airport leaving clear path ahead for the IET to continue accelerating into. This was definitely the case with the 332s and much slower accelerating HSTs. Higher top speeds on shorter hops seem to make little difference. Even with tilt, WCML pendolinos only gain about two minutes on 110mph desiros from Euston to Milton Keynes, a distance of about fifty miles, so on that basis the natural acceleration profiles may give a section time difference from Paddington to the junction of 30 seconds, if anything at all. Perhaps the IET just needs to drive in economy mode as far as the junction, where it can engage 'warp'.
Other rumour is going to join their siblings in Thailand...
Given ETCS has been installed in the Heathrow Tunnels is one part of NR talking to another? Or is this plan about full ERTMS not just ETCS installation?
Is that not the 360s.
I would agree that the time difference between Paddington and Airport Junction would be, at the most, counted in seconds. The 125mph limit starts at and finishes at Acton West, not Paddington, and the distance from there to Airport Junction is all of seven miles. Allowing for acceleration the timing difference would be negligible.
Is it?
ETCS Level 1, which just introduces bailises that operate like ATP in that setting.
Unless I’ve forgotten my ETCS, it should be L1 to keep lineside signals, but L2+ would be interesting to see overlaid over conventional signalling (notwithstanding the PoSA signals).
My understanding is that the ETCS out of Paddington will indeed be an L2 system, with movement authorities transmitted over radio. The movement authorities will be from signal to signal, with the ETCS only authorising a train to proceed if the signal is showing a proceed aspect, so the ETCS will effectively act as an ATP system for the existing signalling.
Not sure what 80xs are, but trains running through the CrossRail core will work under ATO, as this is necessary to achieve the headways. At the Western end, they will switch out of ATO before they cross onto Network Rail territory - I can't recall whether it is intended that the driver will takeover manual control on the move, or while the train is stationary at Paddington "low level". I understand that at the Eastern end the trains will continue under ATO into Stratford station, where the driver will take manual control. I suspect that this will be the first place on NR that has ATO?
By that time, CrossRail will (hopefully!) have been up and running for quite some time. Swapping to a new signalling system will require a lot of work, expense and disruption, not least because it will require extensive retesting. Unless ETCS L3 offers substantial advantages, I think it will be hard to justify either the cost or disruption.
