I did hope that my above comment wouldn’t need repeating (again), but….
You have said this three times today, and about 6 times in total. Repeating something in a Trumpian style does not mean it is true. Where are these “70%” of passengers coming from, and where are they going? What are the current passenger numbers per year for some example flows, and what does improving the connections - in most cases quite marginally - do to those flows? Given that the entire revenue of the Avanti WCML operation is in the order of £1bn pa, it seems extraordinarily unlikley that your proposal would generate ‘billions extra’.
Can you answer this with some detail without simply repeating what you have already written several times?
I have said twice, and others have said more times, that it is not possible to terminate trains at Stratford from the west, nor is it practical to adjust the track layout to do so. Why are you ignoring this obvious flaw to your proposal when it has been pointed out several times?
I and others have pointed out that there are 7 ”Javelins” per hour at peak times, likely to be 8 next year. Again, why are you ignoring this ?
Again, you have stated this three times today and at least six times in total. Repeating something that is wrong does not make it right.
And again (sigh), repeating something multiple times does not make it correct.
To make the ‘existing’ link to the NLL (not NNL) would need rather more work that replacing a couple of bridge spans - which in central Camden is not by any means simple. For one thing the first GC trains to pass each other at Primrose Hill would collide due to the track separation not being fit for GC. All the tracks would need moving, all the signalling replaced, all the OLE replaced (much of which will be out of gauge anyway) all the structures replaced - including the viaduct that runs right through the middle of Camden, which is very definitely not gauged for the GC KE (Kinematic Envelope - you have checked this, right?). And you still need provision for conventional freight and passenger services to operate between Camden Rd and Camden Junction in the WCML. Yet again, why are you ignoring this?
Finally, I’ll give you one more thing to think about. The line speed from St Pancras round the link to the NLL is 40km/h (25mph), and would be lower still to accommodate the significant extra pointwork needed to access the domestic platfroms. The linespeed on the NLL through Camden and on to Primrose Hill is 20mph due to the alignment. It would also be about 600 metres further to the bufferstops on P11-13 at St Pancras (and a further 200 metres to the bufferstops on the Eurostar platforms) from OOC than it is to the buffer stops at Euston HS2. The Euston layout is designed specifically to accommodate the acceleration and braking potential of the trains: 60km/h from the bufferstops, then progressive increases to 160km/h at the same point where your proposed portal is at Primrose Hill. The tail end of a train from Euston will be doing 140km/h + by that point, whereas the tail end of a train from St Pancras will be doing 30km/h, nearly 3km (and over 4 minutes) into its journey.
The HS2 time from Euston to OOC start to stop is 5 minutes. Even using the current linespeeds at St Pancras, ie not the reduced speeds due to the necessary changes to the layout, the time from St Pancras domestic platforms to OOC by your proposal would be, by my estimate, 8.5 minutes, ie 3.5 minutes worse, plus another half minute if using the international platforms. (These times are naturally estimates and may be out by 10% or so, but they are calculated on the same basis so are directly comparable as the error margin will be the same for both).
What allowance have you made for the lost revenue and socio-economic benefit from all the HS2 passengers heading to central London via St Pancras due to this time loss?
A final plea - can you please try to answer these points without resorting to repeating what you have already written several times?
