Tunnelling on the Eglinton Crosstown West Extension started this past spring, with the first of two tunnel boring machines (TBMs) beginning the over six kilometre journey from Renforth Drive to Scarlett Road.

You might have followed along as the tunnel boring machines were delivered to the tunnel launch site piece by piece.

One of those pieces is something called a safety chamber, which is basically a room inside the TBM where crew members working on the tunnel can shelter if something happens during construction and workers aren’t able to safely exit the tunnel.

What is a safety chamber?

Renny and Rexy (the two TBMs digging the Eglinton Crosstown West Extension) are both equipped with safety chambers. Each chamber is 9 metres long, 1.6 metres wide and 2 metres tall and weighs about 6,000 kg. A safety chamber can safely shelter up to 20 people and is equipped with enough food, water and breathable air for 24 hours.

In the rare case of an emergency in the tunnel, it keeps workers safe while they wait for emergency personnel to arrive on site.

While it’s important to plan and prepare for emergencies, these safety chambers are rarely used.

“I’ve been working with tunnel boring machines for 17 years and have never been in a situation where the safety chamber was needed,” says Emidio Tamburri, tunnel construction manager for West End Connectors Construction, the team building the tunnels for the Eglinton Crosstown West Extension.

“But our priority is always to ensure the safety of everyone working on site – and these safety chambers are just one of the ways we’re making sure everyone is safe during construction.”

Tunnelling for this section of the Eglinton Crosstown West Extension is expected to take about 20 months, with the tunnel boring machines travelling about 10-15 metres per day.

These tunnels will form a large part of the Eglinton Crosstown West Extension, which will extend the Eglinton Crosstown LRT another 9.2 kilometres west, to Renforth Drive.

For the latest information on the Eglinton Crosstown West Extension, visit the project website and follow the project on Twitter @EglintonWestEXT.