As
@SamStar proffered a day or so back, as did I, this has to be one of the elephants behind the curtain. The reason for the 'sudden change of stance on the tunnel' wasn't down to altruism or just plain common and business sense. It was down to an ultimatum from the Feds. That might have been coupled with a threat to block an application to 'abandon' the present status of that route, the northern leg of which is still used for freight as well as heavy rail passenger.
Yes, I agree that the "sudden change of stance" wasn't because of altruism. It's well documented that CDPQi did never wanted to share its tunnel, hiding behind circular arguments such as "sharing isn't physically possible under our plans" and "federal regulations don't allow it currently".
However, it's important to remember that all along, it was Minister Marc Garneau who called the shots. Otherwise, VIA was ready to cave in.
As Le Soleil reported in December 2016: (my translation)
Theorically, both the organizations have been in talks for months, but since the Caisse has announced its intention to reserve the Mt Royal tunnel, (to be) acquired from the AMT, for the sole use of its upcoming light rail train.
But the arguments of VIA Rail who pleaded for interoperability of rail infrastructures, weren't getting through.
VIA's president and CEO, Yves Desjardins-Siciliano, who initially was adamant to the access to downtown, now seemed to be getting behind the idea of a transfer station near Autoroute 40.
Thursday, the talks were re-launched during a meeting "facilitated by public servants from Transport Canada", according to VIA Rail's spokesperson Mariam Diaby's own words. "During the next months, along the objective of maximizing the use of existing infrastructure, engineering teams from the CDPQ and VIA Rail will analyze the feasibility of interoperable infrastructure and the use of technologies enabling the cohabitation of the REM and HFR in the tunnel"
https://www.lesoleil.com/actualite/...lle-a-lautre-d31ffcf2f74d7720541e64731ba80b9a
Until I can see some regulatory approval for what is planned for the tunnel, and by deduction, the loss of a functioning heavy rail line presumably but not necessarily still federally regulated, I remain unconvinced that the project can go ahead as stated.
BTW, CN has already made is already well into the process of abandoning its northern freight spurs as part of their agreement with CDPQi.
I remember reading an article about some of their freight customers relocating their activities to the east-end of Montreal as a result.
Btw: Have REM themselves actually stated vehicle width at the floor level?
If you look at one of my previous comments, I posted the specs that rolling stock bidders had to comply with for the REM: