Harvard Bridge

The Harvard Bridge is a steel haunched girder bridge carrying Massachusetts Avenue over the Charles River and connecting Back Bay, Boston with Cambridge, Massachusetts. It is the longest bridge over the Charles River at 659.82m.After years of infighting between the cities of Boston and Cambridge, the bridge was built jointly by the two cities between 1887 and 1891. Originally equipped with a central swing span, it was revised several times over the years until its superstructure was completely replaced in the late 1980s due to unacceptable vibration and the collapse of a similar bridge.The bridge, named for Harvard University founder John Harvard, is locally known for being marked off in the idiosyncratic unit of length called the smoot.ConceptionIn 1874 the Massachusetts Legislature authorized construction of a bridge between Boston and Cambridge, and in 1882 followup legislation set out its location.The bridge was to have a draw with an opening of at least 38ft. Boston interests opposed the bridge, mainly because it did not provide for an overhead crossing of the Grand Junction Branch of the Boston and Albany Railroad. Further legislation in 1885 changed the draw to a clear opening of at least 36ft and no more, until the other bridges below the proposed location were required to have a larger opening. There was still no substantive progress until 1887, when Cambridge petitioned the Legislature to compel Boston to proceed; the resulting act required each city pay half the cost, and allowed Boston to raise up to $250,000 for this purpose, in excess of its debt limit. This implied an estimated cost of US$500,000 for the bridge.