Railway · United States

How much did East Boston Tunnel (1904 Blue Line core) cost to build?

The East Boston Tunnel carried streetcars beneath Boston Harbor from Maverick Square to downtown Boston when it opened on 30 December 1904. It is the historic core of today's MBTA Blue Line, not a construction project for the entire modern line. The Boston Transit Commission began the original tunnel on 5 May 1900. A 1905 engineering account measured the route between Maverick and Court Street at about 7,450 feet and described its twin tracks and concrete construction. Contemporary reporting rounded the opening-era cost to about US$3 million; later financial summaries put the original tunnel at roughly US$3.5 million, so neither number should be presented as a uniquely certified final account. A separate westward extension to Bowdoin opened in 1916. The Transit Commission recorded about US$2.24 million of net cost for that extension by June 1918, while a 1916 contemporary estimate had put it at US$2.4 million. Later conversion to rapid-transit trains and further Blue Line extensions are outside this original-tunnel cost scope.