In all the discussion of new transit lines serving the waterfront, we are also getting into the question of capacity at Union Station Loop.

Since many people will not have seen this design before, and a good quality drawing was just handed out by the TTC at a recent waterfront meeting, I’m posting it here.

The design shows a scheme for a new loop at Union at an interim stage in its development.  Here’s how the design works:

There is space underneath the teamways and outside of the existing tunnel structure to fit two more tracks plus platform space in the north-south direction.  In this design, you will see that the existing (now centre) tracks are disconnected at the south end and all streetcars take the outer loop past the new platform.  Inbound cars unload on the east side of the loop and outbound cars load on the west side.  There is room for four CLRVs on each platform.

Note that the existing platform space at the north end is expanded, and connects directly onto the new northbound Yonge Subway platform to be built as part of the Union Station expansion now underway.

Sometime in the future, if demand warrants it, the loop could be changed so that the east platform was reserved for cars bound to the eastern waterfront while the west platform was used for western waterfront services.  The inner tracks would be reconnected and used as bypass tracks so that the two sets of services could run through the loop somewhat independently of each other.

A further option, although tricky, would be the entry of a “Bremner LRT” (the proposed inner end of the Western Waterfront line) that would punch into the tunnel just south of the loop.  Dodging the pillars would be tricky, but apparently it is possible.