Starting Monday, April 25, the TTC is repairing two subway ventilation shafts on the east and west sidewalks of

• University Avenue just south of Adelaide Street West.

During this project, crews are:

• replacing the metal grate;
• rehabilitating the concrete and steel-beam support structure, by removing the top 0.6 metres (2 feet) of concrete along the shaft perimeter;
• restoring the surface area near the vent after they complete the work.

Since the sidewalk on the west sidewalk near the vent shaft is uneven, the TTC will replace it after it has complete the vent-shaft work.

Crews must work overnight to prepare for the project. Starting 12:01 a.m. Monday, April 25, they set up a safe work zone for both vent shafts and install supports to secure a work platform in each of the vent shafts from street level. They continue to install supports for both vent shafts overnight during the first week. They’ll also work overnight when they remove the platform at the end of the project.

During the project, crews maintain sidewalk access to both work areas and to the laneways near both sidewalks. The work zone will block the curb lanes on University Avenue between Adelaide Street and Pearl Street. Crews are storing material and equipment in the traffic lanes.

Except for periods of overnight activity at the start and end of the project, crews mostly work Mondays to Fridays from 7 a.m. until 7 p.m. Occasionally, they may work Saturdays after 9 a.m. to make sure the project remains on schedule. They use a concrete saw-cutter, hand-held power chipping tools, a generator, scaffolding, a small crane and concrete truck when necessary.

Once they have safely installed the platform in the vent shafts, the loudest noise will occur during daytime hours when crews cut and remove concrete.

The TTC continues repairing the ventilation shafts on University at Adelaide West “for approximately eight weeks”, meaning construction continues as late as until June 25.