The building was a much-anticipated landmark designed by a well-respected architect, but was known in the 1970s for its
engineering flaws as well as for its
architectural achievement. The opening of the building was delayed from 1971 to 1976, and the total cost is rumored to have increased from $75 million to $175 million. It was an embarrassment for the firm, for modernist architects, and for the architecture industry. During the
excavation for the tower's foundation, temporary steel
retaining walls were erected to create a space in which to build. The walls warped, giving way to the clay and mud fill of the
Back Bay which they were supposed to hold back. The shifting soils damaged utility lines, the sidewalk pavement, and nearby buildings—including the historic
Trinity Church across St. James Avenue. Trinity Church won an $11 million lawsuit to pay for repairs. in 2007; on the left is
Copley Square (and
Trinity Church), to the upper left is the
Boston Common, on the right is the
Massachusetts Turnpike (I-90) and to the top right is
Logan International Airport. In October 1973, I.M. Pei & Partners announced that all 10,344 window panes would each be replaced by single-paned, heat-treated panels at a total cost between $5 million and $7 million. Glass panes were sold to
Hingham-based discount retailer
Building #19, who sold them for $100 apiece. They advertised "If it does fall out, we promise to sell you the replacement plywood very cheap." It took many months to diagnose problems and repair the building. Sheets of
plywood replaced many of the missing glass windows of the building, earning the tower the nicknames "Plywood Ranch" (the same name as a local
lumber yard chain at the time) and "Plywood Palace", much to the consternation of the vice president in charge of construction. According to engineers Matthys Levy and
Mario Salvadori, the replacement also inspired jokes that the Hancock Tower was the "world's tallest wooden building." The building's upper-floor occupants suffered from
motion sickness when the building swayed in the wind. To reduce the movement, contractors installed a
tuned mass damper on the 58th floor. As described by
Robert Campbell, architecture critic for
The Boston Globe: Two 300-ton weights sit at opposite ends of the 58th floor of the Hancock. Each weight is a box of steel, filled with lead, 17 feet square by 3 feet high. Each weight rests on a steel plate. The plate is covered with lubricant so the weight is free to slide. But the weight is attached to the steel frame of the building by means of springs and shock absorbers. When the Hancock sways, the weight tends to remain still, allowing the floor to slide underneath it. Then, as the springs and shocks take hold, they begin to tug the building back. The effect is like that of a gyroscope, stabilizing the tower. The reason there are two weights, instead of one, is so they can tug in opposite directions when the building twists. The cost of the damper was $3 million. The dampers are free to move a few feet relative to the floor. According to Campbell, engineers discovered that—despite the mass damper—the building could have fallen over under a certain kind of wind loading. The structure was assessed as more unstable on its narrow sides than on the big flat sides. Some 1,500 tons of diagonal steel bracing, costing $5 million, were added to prevent such an event. ==History==