Hoosac Tunnel was commenced in 1851 and completed in 1875. The total length 4 3/4 miles long and is the longest tunnel in the United States. Rock excavated 1,900,000 tons. Men employed during construction were about 900. Lives lost 192. Width 24 feet, height 20 feet. The bore on left was the original starting point of the tunnel. Equipment with Electroal service 1911.