The TBM Don Experience

The week of March 13, 2017, the Eglinton Crosstown light rail transit (LRT) project marked another significant milestone. Metrolinx began the process of extracting the tunnel boring machines (TBM) from the completed east tunnels. TBM ‘Don’, the machine that bored the north tunnel, was the first machine to be lifted to surface. He was disassembled and lifted from extraction shaft just east of Yonge & Eglinton in four over-sized sections over four days. 

The morning of March 13th, the cutter head – of the ‘face’ of the machine – was the first piece removed. John Brown, Construction Lead for Tunnels and Cross Passages (East Tunnels), describes how TBM Don’s cutter head made its ascent.

“It looks like a flying saucer!” Those were the words used by many gathered to witness the massive, circular hunk of metal that emerged from Eglinton Avenue on that cold March morning.

TBM Don’s cutter head was 6.5 metres wide. The blades on the machine were once again exposed to the daylight after boring through the earth for almost a year as part of the Crosstown LRT project.

The crowd was made up of those who had heard about the event in advance, and others who were stopped in their tracks once they saw the steel disc swinging overhead. Some even made a point of watching through windows in nearby buildings just to get a glimpse – everyone in awe of what they were witnessing. Despite the cold morning, it turned in to quite the spectacle, with Community Relations staff doling out coffee and hot chocolate to passersby up and down the Midtown sidewalk. 

We captured your reactions to seeing the massive section of metal lifted and swung out over Eglinton Avenue. 

The day provided many a chance to watch just one of Don’s pieces come to the surface. Over the course of the week, more large pieces of the 10-metre long cylinder were brought out. Each were hoisted onto the back of a truck and hauled away to a storage facility.

“Don’s” journey up through the extraction shaft, and slowly moved out over the roadway before being placed on the ground, wasn’t far at all compared to the 3.3 kilometres he had travelled underground to get to that point. The fascination many had on that day was not only the sheer size of the object they were looking at, but also the thought of how much work it had done to burrow the tunnel beneath their feet, where Toronto’s transit future will soon be. 

Watch this great time-lapse video of cutter head’s journey, from end to end.