About 25 members had an eye-opening morning on November 26 getting briefed on the Metro Tunnel project. We had an hour at the Swanston St PR centre surrounded by models and 180deg video displays, with a knowledgeable presenter filling us in with amazing facts.Pinnacle of the exercise was of course the four giant boring machines. Each is 120m long, equal to three big trams end-to-end, and weighing 1100 tonnes. The cutter head is 7.3m diameter. The borer creeps it way at about 10m per day, sealing the tube as it goes and pumping out the dirt to the surface after converting it to a slurry.
We learnt that for the UK-France tunnel project, the giant borers were too awkward to recover when their job was done, so they were buried deep for eternity. Below: Member Jim dons his virtual reality 4D mask.
The Melbourne ones each have a female name, Joan, Meg, Alice and Minnie after celebrated Victorian ladies. Things underground generally have female names, something to do (we were told) with St Barbara the patron saint of mining whose head was cut off by her own father (what the mining connection is, we’ve forgotten).
Afterwards, many of us trooped to coffee at Dymocks, our heads bursting with arcane knowledge about Melbourne’s underground low-jinks.
Afterwards, many of us trooped to coffee at Dymocks, our heads bursting with arcane knowledge about Melbourne’s underground low-jinks.