The Pequabuck Tunnel through Sylvan Hill, one of the great railroad building feats of Connecticut was started on February 21, 1907 and completed three years later.
Work on the tunnel was interrupted during the panic of 1908, owing to the stringency of the money market, when only about three hundred feet had been excavated. Operations resumed on July 17, 1909 with a force of seven hundred men working in day and night shifts. Inside of a year the men cut through about 3,500 feet of hard mica and scaly formation. In all, about 4,600,000 cubic feet of earth and rock had been taken out. During the operations, the opening up of several springs delayed the work. The tunnel was constructed under meadowland, woodland, and a pond.
Dimensions of the tunnel, a cemented tube are: 3,850 feet long, 32 feet wide and 26 feet high. There are recesses at 30 foot intervals.
