About 10 metres under Richmond Road, there’s a steady, droning hum.
It’s the sound of crews compacting massive amounts of earth that bury the concrete roof of a tunnel along the LRT western extension.
CBC News reporters walked a 1.1-km stretch of that tunnel on Friday, as workers installed rebar that will support a concrete pedestal for the rails.
Structural work on that tunnel is slated to finish this summer, while track work should be done next spring.
Anchors are already installed to hold up the overhead electrical system, which should be in place by the end of next year. Trial running is expected to start in 2026, with delivery of the LRT extension to the city at the end of that year, about a year and a half behind schedule.
City construction manager Jacelyn Daigle said she’s standing by that timetable.
“We’ll have to see as we get closer, but today, with the known information we have, the design we have, the progress we have, it’s very reflective of what we’re seeing,” she said.
The work is what’s known as a “cut-and-cover” operation, entirely different from the more expensive boring method used to dig the Stage 1 LRT tunnel under downtown.
This work requires digging open trenches, moving more than 400,000 cubic metres of earth and pouring more than 100,000 cubic metres of concrete. Crews have used giant hydraulic machines that roll along the trench, pouring three separate walls and a roof all at the same time — an important time saver that’s helping keep to the schedule.
They had to cut through rock and around utility lines. Even now, there are gas, hydro and telecommunication lines hanging over open parts of the trench, waiting to be buried.
Daigle said her team has learned lessons from the mistakes of Stage 1 construction, which resulted in a downtown tunnel that’s suffered from water infiltration near Rideau Station.
“There was no dedicated construction management team on Stage 1,” she said. “In this case we have our own dedicated field co-ordinators. We’re in the field having a look, making sure there’s no quality corners being cut, making sure that we get ahead of issues.”
She called the west tunnel’s waterproofing a “priority” and said the tunnel uses a “very solid system” that’s different from the one downtown.
WATCH | What it’s like inside the tunnel:
Put on a hard hat and walk alongside CBC Ottawa’s Arthur White-Crummey as he shows you parts of a tunnel under construction along the LRT western extension.
The west extension will run from Tunney’s Pasture Station to the future Moodie and Baseline stations, with a total of 15 kilometres of rail and 11 new stations.
It has two tunnels — one running about three kilometres and the other 270 metres — plus an open trench near Pinecrest.
In total, Stage 2 of Ottawa’s LRT is expected to cost $2.57 billion.
