It absolutely is an issue and you just have to look at your map, because you are constrained by the Expressway on the one side and the orange line on the other. So you either have to dig at least 30 meters deep (Bonaventure Station is
22.6 meters deep) or you are going to build your station in very constrained space.
You wouldn't go under (or over) Metro Bonaventure (or are you referring to the now demolished CN Bonaventure Station - which would have solved this entire mess). There's plenty of room between the platforms of the metro station and the cathedral for 4 tracks. As I pointed out above, the east end of the Alto platforms would be around de la Gauchetiere and Peel. And as I pointed out before, that pedestrian tunnel from Metro Bonaventure is expendable. Something can be restored later on, if they need to remove it for construction. And any deep tunnel would remain north of the Orange line, let alone Ville Marie. Though the case you make perhaps justifies turning north by Peel. What's the necessary distance you need to drop down to get under the REM trench at President Kennedy?
Good luck finding an Engineering firm (disclaimer: I happen to work for one which takes on reasonably large railway infrastructure projects like the
Sawtooth bridge replacement on the Northeast Corridor) which would accept building such a monster underneath the foundations of Place Bonaventure and Bell Centre...
Place Bonaventure is east of Peel; and if you recall, it's more of a bridge than anything else. I don't think either would be in the way. Though if they were - then knock them down - and they can use the land as part of a TOD. Why Place Bonaventure wasn't demolished years ago I don't know - that shopping mall completely failed, and the space is horrific for events - like some kind of dungeon. Even in the 1980s I thought it was as ugly as sin - completely brutal (pun intended).
Very simple: The connection from Old Oak Common to Euston is essential to get the overwhelming majority of HS2 passengers closer to downtown.
Pish. Euston has always been a compromised location - and the station would never have been there if it could have gone further south. And the east-west transit connections have always been poor - it's quite the walk to the Metropolitan/Hammersmith/Circle lines - although at least the new terminal will be better connected to Euston Square. But at the cost of making it a good trek to the Victoria and Bank-branch platforms. If they'd have done this properly, they'd have come into Paddington, built built a new (but likely impossible) terminal at Tottenham Court Road Station. Old Oak Common though is a decent compromise for a terminal. It's only a single stop on the Elizabeth line to Paddington, and three to Tottenham Court Road, with excellent connections to Heathrow, the City, and Canary Wharf. It's not like there's that much around Euston that makes it a centre - other than Euston. And personally anywhere I've travelled from Euston, will now be more accessible from Old Oak Common. The only advantage to Euston is that it get's the terminal to only just more than a kilometre to St. Pancras International. (which begs the question of why they couldn't spend $billions to instead bring HS2 to somewhere closer to HS1, rather than building the new station (that's on the wrong side of Euston station to boot).
Maybe there were no other options - and this is where not even trying to put it into Euston might be a better idea, as I don't think it would improve most travel times, rather than terminating at Old Oak Common. Which they seem to be on to, given the delays and possible cancellation of the the connection to Euston. Anyhow, with the extension to Euston opening about 5 years after HS2 service to Old Oak Common begins, I guess we'll see.
Conversely, any downtown Montreal tunnel would only really benefit a small minority of the ALTO ridership.
I agree - I'm surprised they are going for a tunnel option. But if they are, the alignment shouldn't be the same as Central. I'm not sure the point of debating what we both agree isn't worth it - it's what they are planning that's of interest.
As you will see, it suggests that only 20% of total ALTO ridership would travel east of Montreal
Which is why the project should simply be Montreal to Toronto via Ottawa. But we all know - and have known since Trudeau's original announcement in the late 1970s. And with Trudeau's endless pandering to the west, even Edmonton and Calgary had to be included that time. Fortunately the Liberals seem to have finally realized that sacrificing huge amounts of money and selling out Canada's oil to the richest province will never buy them votes.
It's an urban myth that HSR depends on gaining high speed really fast.
I'm not sure what you are referring to. Obviously the travel speed through Montreal West and NDG - and from Union up the Don, are not going to be 300 km/hr (mind you, the track from Montreal West is very straight ...)
Let's have a look at the TGV Paris-Strasbourg and see how fast the speed limits actually allow it to gain its top speed:
View attachment 633745
As you can see, the Paris-Strasbourg TGV never exceeds 130 km/h before it hits the equivalent distance of the entrance to the Taschereau Yard.
Yeah, it doesn't hit 130 km/hr for 10 km; but it's 120 km at only 1.7 km. I don't see that they are going to hit 120 km heading west from Central station which barely gets you to the Lachine canal. It's another 3 km of tight curves to get to the CN mainline at St. Henri.
and doesn't stop the TGV from covering the 439 km between Paris and Strasbourg (to compare: OTTW-BRKV-KGON-TRTO is 446 km) in 1h44, thus at an average speed of 253 km/h (i.e., well above the 180-200 km/h ALTO's own travel time targets imply).
But on the HS1, they started off with a very compromised slow (but visually interesting) winding path into Waterloo International before building 20 kilometres of new tunnel into London to cut 20 minutes off the travel time. Good grief, they used to go out to Battersea!
In summary, I wouldn't hold my breath for ALTO ever reaching beyond Montreal, let alone: for a Montreal tunnel to become part of this project (if it ever happens)...
It is a riskier part of the project - but it's clearly what they are currently looking at - though I'm sure it will all change 5 times during the next phase. But even if they don't ever serve past Montreal, I'd be surprised if they don't build a downtown Montreal terminal for future eastward extension into a new tunnel.
... all kinds of options, and one that corresponds to the strange new map we have.
Hmm ... I wonder what happened if you stretched the drawing they released onto a proper map, at scale. It's not actually a non-schematic map is it - at least for the existing alignment sections (i.e. to scale).
Is it actually reflecting the existing parts of the alignment we expect will still be used ... say between Montreal and Ottawa ... and from Toronto up to Claremont? That dog-leg from Smiths Falls(?) to Ottawa looked odd to me - almost as if it was using some of the very old abandoned alignment up to Arnprior or something - which seems bizarre giving they already own some pretty straight track.
