[zang]

Something like this:

View attachment 700766

At ~4.4 km, you are probably looking at about $1 billion to tunnel it as per latest cost comparables and $2-3 billion for fitout and a mined terminal station at Union. If you are willing to cut travel speeds you could probably reduce the tunnel length to something closer to 3km.

Expensive, but it would give ALTO completely separate (i.e. reliable) operations in and out of Toronto and would let trains get from Union to the edge of the City, assuming an average speed of 150km/h between Union and Markham, in about 11 minutes. Doing the Union-Kennedy-Agincourt route is probably looking at more like 21-22 minutes.

Why not just exit a tunnel on the approach to Union? A train's going to need to slow down anyway, it doesn't seem like you're going to gain a lot of speed by keeping it completely underground at the station.

 

[Urban Sky]

Why not just exit a tunnel on the approach to Union? A train's going to need to slow down anyway, it doesn't seem like you're going to gain a lot of speed by keeping it completely underground at the station.

The underground station is unfortunately the most expensive, disruptive and complex element of the tunnel he sketched…

 

[crs1026]

1968 data applicable to RDC equipment:

CP Agincourt to Leaside (5.3 miles) - 60 mph
30 mph turnout at Leaside, passenger stop at Leaside station
Leaside to Don (3.5 miles) - 50 mph on curves, 75 mph otherwise
Don to Union - (2.0 miles) - 30 mph, 15 mph over turnouts at Cherry and Scott St interlockings

Scheduled timing Union to CP Kennedy (Jct with Havelock Sub) - 16 minutes eastbound, 16-24 mins westbound

Seems to me that spending upwards of a couple billion dollars to bore a tunnel to improve on that performance is pretty wishful thinking.

- Paul