Machines | Sydney Harbour Tunnel

One of the great engineering feats of modern Australia was the construction of the Sydney Harbour Tunnel. For more than 100 years, crossing Sydney Harbour via a tunnel had been just a dream. A tunnel had been suggested as early as 1885, when it was realised that ferries were perhaps not the most efficient way to get large numbers of people, carriages and horses across the harbour. When the Sydney Harbour Bridge was built in 1932, traffic was projected at 13,000 crossings per day. The sort of traffic the designers had in mind included "cars, horses and cattle, pigs and sheep". By 1986, the same number of cars was crossing the bridge in an hour. In 1979, Government called for alternative traffic solutions, including proposals for both bridges and tunnels. All proposals submitted involved the demolition of a large number of dwellings, and were rejected. In 1984, Transfield was approached by consulting engineers Wargon Chapman Partners to study a solution to building a tunnel without intervention to the inhabited areas to the North and South of the bridge. A joint venture was formed with Kumagai Gumi, a large Japanese construction company with extensive experience in tunnel construction and immersed tube technology. (From the Transfield Archive).