Using Google Earth, I've been trying to conceptualize how the Havelock sub would need to be realigned to support the continuous 110mph (177 km/h) speed limit required to achieve VIA's 160km/h average speed claim. First I drew 1300m and 1800m curves on the ground, which are the minimum radii at 200km/h for tilting, and non-tilting trains respectively, according to
that chart on Wikipedia. Then I tried to free-hand an alignment that keeps the curve radii above 1300m (tilting trains @ 200km/h).
In the image below, the current ROW is in blue, and my free-hand realignment is in yellow. This segment of the line is so curvy that when the minimum curve radius is increased, almost none of the original ROW can be reused. The current ROW has one beautifully wide curve on the right side of the image that can be reused, but then to the east the line gets very squiggly and would need to be bypassed again.
View attachment 114284
Location:
44°41'40.28"N
76°57'55.35"W
I roughly measured the radius on Google Earth similarly to how I drew the radii in the image above, by trying to find the point equidistant to all points along the curve.
When they say the West Coast Mainline is curvy, it's relative. The East Coast Mainline and Great Western Mainline have enormous curve radii, on par with some modern 200-250km/h high-speed-rail lines. The curve below on the Great Western Mainline just outside Didcot (randomly selected, they all seem similar in that segment) appears to have a radius of about 5000 metres.
View attachment 114289