Revitalization of the Copley Headhouse

By Keith M. Bouchard, E.I.T.

Traveling on the Green Line, the oldest and most-maligned of Boston’s color-coded subway lines, is rarely a pleasurable experience.  The mere mention of it usually conjures images of above-ground trolleys creeping through traffic and jammed with packs of sneering commuters and rowdy college students.  The typical priority of a Green Line rider is to exit the crowded cars and dimly lit stations as soon as possible for the open air of the streets, or at least the relative luxury of the Red Line.  One rarely looks around at what he or she is passing through.  The main branch of the Green Line is, after all, the oldest subway tunnel in America.  The stations themselves are historic, many being National Historic Landmarks.  Nowhere is this history more apparent – or aesthetically pleasing – than in the ornate iron-clad headhouse at Copley Station.

Years of exposure and deferred maintenance had left the historic headhouse, which sits in the shadows of the Boston Public Library, in a poor state.  The cast-iron cladding was deteriorated and the steel back-up structure, which supported the ironwork, had corroded through.  It was decided by the MBTA that, as part of the recent renovation to make Copley Station accessible, the headhouse would undergo a historical restoration.

CBI worked directly with DeAngelis Iron Work, the metal fabricator hired to restore the cast-iron cladding, to design the steel structure of the headhouse.  The structure had to support the code-required wind, seismic, and snow loads as well as unanticipated loads from revelers during the next Patriot’s Super Bowl parade (coming soon).  The structure needed to meet all these requirements while maintaining the original envelope created by the ironwork, which would be restored in-kind.  CBI created a computer model of the partially enclosed structure to analyze the different load cases.  None of the original vertical structural elements were salvageable due to corrosion; however, the original roof beams were able to be re-used in the design.  Galvanized steel was used for all new steel elements to slow the rate of corrosion.  As can be seen in the photos, the result of the restoration is worth stopping – or at least slowing down – to admire.