The second phase of repairs to the Tunnels in the Great Whyte began in March 2016, by the same Swedish Construction Company SKANSKA. A section of tunnel, underneath the central pavement was exposed, opposite the TSB Bank, which showed the tunnel roof had started to sag inwards. It was repaired by putting a wooden former underneath the arch, removing the bricks, then re-building the arch again with new engineering bricks, the same as they did in 2014.
When this small section had been fixed they realised that the rest of the tunnel was in the same condition and was unsafe to repair in the same way. So an alternative plan was made, it consisted of scaffolding the tunnel from the position shown, up to the Chamber near the clock inside the tunnel and putting what they called a crash decking on it. This enabled them to take the roof of the tunnel down in a controlled way, with the crash decking protecting the river below. The slideshow below shows the crash decking.
Once the roof had been taken down, a wooden former was made to fit from one side wall across to the other side wall in the form of an arch. The former was then covered with a skin of flexible ply wood, and then new engineering bricks were built across to form the new roof. This work was carried forward towards the Memorial Clock until they reached the chamber. The chamber is approximately 25ft wide x 12ft long and had a wonderful curved vault like roof, which had to be demolished. This was replaced by a plain concrete slab!
If you would like to see more photos of the 2016 repairs click this link.