Two, with lay-bys/passing tracks...for *freight*! This is outlined in the IBI report. That's predicated on the most modern signalling and control being in place.
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I can't say precisely how problemmatic a MacTier routing would be for CP, but a couple of things are known.
First, a Bypass MacTier route is longer than the straight shot down the current line, so logic says a little more expensive. The added mileage also affects crew usage, since many runs only just make it end to end before their time on duty limits kick in.
Second, the Mactier segment has some single track segments, and the North Toronto segment has CTC orders prohibiting trains from standing and waiting in places.....and two grade crossings at Osler and Bartlett that can't be blocked. Adding the Galt Sub traffic would mean more trains stopping and waiting to pass each other, whereas the Galt Sub has so much double track that trains mostly pass without stopping. Layman's logic says it's likely that this would constrain operations and make trips longer.
IBI may offer a theoretical view, but only the railways know what their must haves are. Eg an island of most modern signalling may not work unless CN intends to install similar throughout the region....otherwise their locomotive fleet may not have the necessary electronics installed.
I put more faith on CN and ML reaching an agreement than not. That will inform what is needed. It would make much of the legal stuff moot - Ottawa will be happy to endorse a voluntary agreement between Ontario and CN. The legal stuff is simply the worst-case alternative that creates the desire for a mutually agreed solution.
- Paul
PS - operational inconvenience does not imply negative impact on the balance sheet. Railways do some very painful things to improve the balance sheet. Lower capitalisation, relief from the fixed costs of owning the Galt Sub, cash in hand from selling the line - there is a lot of upside to CP buying in even with an inconvenient detour routing.
- Paul