Main Street Tunnel technique, whereby the tunnel was excavated, the concrete poured, and the structure buried, on top of which the canal channel was built. This avoided costly boring beneath an active waterway; the structure cost C$11 million. This price was split 50–50 between Transport Canada and the St. Lawrence Seaway Authority. The tunnel opened with a parade featuring the Welland Police pipe band and various officials on the morning of May 20, 1972. Main Street Tunnel The Main Street Tunnel, located in Welland, Ontario, Canada, is an underwater tunnel, carrying Niagara Road 27 and the unsigned designation of Highway 7146 under the
Channel Tunnel forecast. Working from both the English side and the French side of the Channel, eleven tunnel boring machines or TBMs cut through chalk marl to construct two rail tunnels and a service tunnel. The vehicle shuttle terminals are at Cheriton (part of Folkestone) and Coquelles, and are connected to the English M20 and French A16 motorways respectively. Tunnelling commenced in 1988, and the tunnel began operating in 1994. In 1985 prices, the total construction cost was £4.65 billion (equivalent to £ billion in 2015), an 80% cost overrun. At the peak of construction 15,000 people were employed with daily expenditure