actually, the Ottawa system will have 120 meter platforms (underground), allowing for 130 meter trains (nose and ass will go 5 meters over platform) for a "comfort" capacity of 24,000. The original plans called for 180 meter platforms and reduced twice to 150 and 120 for cost savings.
What is truly sad about the cancelation of the 1977 plan is that we never got a proper urban rapid transit system. If it would have been built as shown, it would have been much easier to add other lines in the future (such as the Bank Street line).
The current plan is the best in decades, but I'm disappointed in capacity considering it was reduced by 1/3 for the original plan 5 years ago. Also, I don't like the fact that this plan is very suburban-centric, stretching every dollar to get it as far as possible (see Stage-2 below). That said, I'm still happy they will add (Gladstone, New Orchard, Cleary) and upgrade (Dominion, a barely used, kind of hidden station in one of the most vibrant old Ottawa neighborhoods) a few urban stations.
If only we could also build a line under Bank-Rideau-Montreal we'd be set.