The John Hancock Tower, colloquially known as the Hancock, is a 60-story, skyscraper in the Back Bay neighborhood of downtown Boston, Massachusetts. The pinnacle height (including antennas) is . Designed by Henry N. Cobb of the firm I. M. Pei & Partners, it was completed in 1976, and has held the title as the tallest building in New England ever since. In 2015, the lease belonging to the John Hancock Mutual Life Insurance Company, for which the skyscraper was named, expired, and it was renamed to its address at 200 Clarendon Street.

The building is widely known for its prominent structural flaws, including an analysis that the entire building could overturn under certain wind loads and a prominent design failure of its signature blue windows, which allowed any of the window panes to detach and fall, up to the full height of the building, endangering pedestrians below.

The street address is 200 Clarendon Street, but occupants also use "Hancock Place" as a mailing address for offices in the building. John Hancock Insurance was the primary tenant of the building at opening, but the company announced in 2004 that some offices would relocate to a new building at 601 Congress Street, in Fort Point, Boston. The tower was originally named for the insurance company that occupied it, which in turn was named for John Hancock, a signatory of the United States Declaration of Independence.

History

Development and engineering flaws

thumb|left|The tower during the time when windows that had fallen out were replaced with plywood

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.

thumb|right|253px|The John Hancock Tower seen from the [[Prudential Tower 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:

<blockquote>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.</blockquote>

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. On March 30, 2009, Hancock Place was sold at auction for $660 million ($20 million was new equity and the $640 million of in-place debt was assumed by the buyer) to a consortium of Normandy Real Estate Partners and Five Mile Capital Partners. The companies had been slowly increasing their investment over the previous months. In October 2010, Boston Properties acquired the John Hancock Tower for $930 million. As part of the purchase agreement, the name "Hancock Tower" would expire along with John Hancock's lease in 2015.

<gallery class="center" widths="225px" heights="250px" caption="Visual aspects">

File:John Hancock Panorama.jpg|Full vertical view of the John Hancock Tower

File:John Hancock Tower Sky.JPG|Cloud reflections on the glass sheathing

File:Hancockslimside.JPG|The dark vertical notch is prominent in this view.

</gallery>

In 1977, the American Institute of Architects presented the firm with a National Honor Award for the building, and in 2011 conferred on it the Twenty-five Year Award.

Observation deck

An observation deck at the top of the tower was a tourist attraction for several decades. However, it was closed after the September 11, 2001, terrorist attacks. After the closure of the John Hancock Tower's observation deck, the building with the highest observation deck open to the public in Boston became the Prudential Tower. The building's owners cited security as the reason for the closure in the years following. They rented the deck for private functions and expressed intent to replace it with more office space. Boston city officials contended that security concerns were moot, since most similar attractions had long since reopened. In addition, they note that a public observation deck was a requirement for the original building permits to gain public benefit from the high tower. However, officials have not been able to locate the documentation of this requirement.

In 2023, the Prudential Tower’s top floors reopened as View Boston, a multi-level observatory and dining attraction.

thumb|upright|View of the John Hancock Tower during a [[blue hour]]

About a year after the falling windows problem was resolved, American novelist John Updike wrote in a story,

In September 2015, the French photographer and artist JR created a tall mural of a man wearing shorts, between the 44th and 50th floors of the building. According to the property manager, the mural was the final piece in a three-part series of temporary public art projects at the building.

See also

  • John Hancock, for whom John Hancock Insurance was named
  • Prudential Tower for an image of the Boston skyline from Cambridge in 1963, with the old 26-story Hancock building a conspicuous landmark.
  • List of tallest buildings by U.S. state
  • List of tallest buildings in Boston

References

Notes

Sources

  • October 15, 1973. "Those Window Pains", TIME.
  • Harl P. Aldrich, James R. Lambrechts (Fall 1986). "Back Bay Boston, Part II: Groundwater Levels", Civil Engineering Practice, Volume 1, Number 2.
  • 200 Clarendon Street Website for the building, under its current name.