| Hancock Place | |
|---|---|
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| John Hancock Tower in April 2009 | |
| Information | |
| Location | 200 Clarendon Street, Boston, Massachusetts, United States |
| Status | Complete |
| Constructed | 1968 - 1976 |
| Use | Office |
| Height | |
| Roof | 790 ft (240.7 m) |
| Technical details | |
| Floor count | 60 |
| Companies | |
| Architect | I.M. Pei & Partners |
| Developer | Beacon Capital Partners |
The John Hancock Tower, officially named Hancock Place and known colloquially as The Hancock, is a 60-story, 790-foot (241 m) skyscraper in Boston. The structure, the tallest in the city, was designed by I.M. Pei and Henry N. Cobb of the firm now known as Pei, Cobb and Freed and was completed in 1976. In 1977 the American Institute of Architects presented Cobb with a National Honor Award for the John Hancock Tower. The John Hancock Tower has been the tallest building in Boston for over 30 years, and is also the tallest building in New England and the 172nd tallest building in the world.
Its street address is 200 Clarendon Street. The company uses both "Hancock Place" and "200 Clarendon Street" as mailing addresses for offices in the building. The John Hancock companies were the main tenants of the tower, but the insurance company announced in 2004 that some offices will relocate to a new building at 601 Congress Street. It sits prominently near Copley Square in Boston's Back Bay.
Like all large, heavily glazed buildings, the tower requires substantial air conditioning year round—even with its reflective walls. Its cooling system is similar to that used in the IDS Center in Minneapolis, Minnesota.
Contents |
Design
Tall, skinny glass structures were a goal of modernist architecture ever since Mies Van Der Rohe proposed a glass skyscraper for Berlin. Such buildings as Gordon Bunshaft's Lever House, Mies' Seagram Building, and Frank Lloyd Wright's Johnson Wax Headquarters attempted this goal, but many of these designs retained structural artifacts that prevented a consistent, monolithic look.
In 1972, Pei and Cobb's design of the Hancock Tower took the glass monolith skyscraper concept to new heights. The tower is an achievement in minimalist, modernist skyscraper design.
Minimalism was the design principle behind the tower. The largest panes of glass possible were used. There are no spandrels panels, and the mullions are minimal. Pei and Cobb added a geometric modernist twist by using a parallelogram shape for the tower floor plan. From the most common views, this design makes the corners of the tower appear very sharp. The highly reflective window glass is tinted slightly blue, which results in the tower having only a slight contrast with the sky on a clear day. As a final modernist touch, the short sides of the parallelogram are marked with a deep vertical notch, breaking the tower's mass and emphasizing its verticality.
Problems with the building
It was a much-anticipated landmark from the country's most respected design firm. Unfortunately, the tower was once more notorious for its engineering flaws than for its architectural achievement. Its opening was delayed from 1971 to 1976, and the total cost is rumored to have rocketed from $75M to $175M. It was an embarrassment for the firm, modernist architects, and the architecture industry.[citation needed]
Foundation
Hancock Tower was plagued with problems even before construction started. During the excavation of the tower's foundation, temporary steel retaining walls were erected to create a void on which to build. The walls warped, giving way to the clay and mud fill they were supposed to hold back. The inward bend of the retaining walls damaged utility lines, the sidewalk pavement, and nearby buildings—even damaging the historic Trinity Church across the street. Hancock ultimately paid for all the repairs.
Falling glass panes
Inventing a way to use the blue mirror glass in a steel tower came at a high price.
The building's most dangerous and conspicuous flaw was its faulty glass windows. Entire 4' x 11', 500 lb (1.2 x 3.4 m, 227 kg) windowpanes detached from the building and crashed to the sidewalk hundreds of feet below. Police were left closing off surrounding streets whenever winds reached 45 mph (72 km/h). According to the Boston Globe, a scale model of the entire Back Bay was built in MIT's Wright Brothers Wind Tunnel to identify the problem. The research raised questions about the structural integrity of the entire building (due to unanticipated twisting of the structure), but did not account for the loss of the glass panels. An independent laboratory eventually confirmed that the failure of the glass was due to oscillations and repeated thermal stresses caused by the expansion and contraction of the air between the inner and outer glass panels which formed each window; the bonding between the inner glass, reflective material, and outer glass was so stiff that it transmitted (instead of absorbing) the force to the outer glass and eventually caused it to fail.[1]
In October 1973, I.M. Pei & Partners announced that all 10,344 panes would be replaced by a single pane, heat-treated variety,[2] costing between $5 million and $7 million. During the repairs, plywood replaced the building's empty windows, earning it the nickname Plywood Palace and the joke that it was "the world's tallest plywood building".
Nauseating sway
The building's upper-floor occupants suffered from motion sickness when the building swayed in the wind. To stabilize the movement, a device called a tuned mass damper was installed 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 (5.2 m) square by 3 feet (0.9 m) 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. LeMessurier Consultants says the dampers are located in relatively small utility rooms at each end of the building, leaving most of the 58th floor usable.
According to Robert Campbell, it was also discovered that—despite the mass damper—the building could have fallen over under a certain kind of wind loading. Ironically, it could tip over on one of its narrow edges, not its big flat sides. Some 1,500 tons of diagonal steel bracing were added to prevent this, costing $5 million.[3]
Closure of the observation deck
An observation deck with spectacular views of Boston was a popular attraction. It was closed after the September 11, 2001 Terrorist Attacks[4] and remains closed as of fall 2008 (like the Transamerica Pyramid in San Francisco). Because of the closure of the John Hancock Tower's observation deck, the highest observation deck in Boston that is open to the public is in the Prudential Tower.
The building's owners cite security as the reason for the continued closure, but have used the deck for private functions and have expressed intent to replace it with more office space. Boston officials contend that security concerns are moot, since most similar attractions have long since reopened, and that a public observation deck was a requirement for the original building permits, though the city can't seem to produce documentary evidence.1
2009 foreclosure and auction
In 2006, Broadway Partners acquired Hancock Place for $1.3 billion. By 2009, they had defaulted on the loans they used to buy the building, and it fell into foreclosure. On March 30, 2009, Hancock Place was sold at auction for $660 million (of which $640 million was to pay off the seller's debt [5]) 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. [6]
Note on company name
The company that built the Hancock Tower and two earlier similarly-named buildings is known loosely as "John Hancock Insurance," or simply "John Hancock." It was known as "The John Hancock Life Insurance Company" in the 1930s and "The John Hancock Mutual Life Insurance Company" in the 1940s. As of 2000, the company owning the buildings was "John Hancock Financial Services, Inc." with various subsidiaries such as "The John Hancock Variable Life Insurance Company" and "Signator Investors, Inc." In 2003, the company was acquired by the Canadian Manulife Financial Corporation, but still uses the name "John Hancock Financial Services, Inc." and those of various subsidiaries.
References
- Note 1: Park, Madison. "Searching for an answer on 60th floor: Councilor wants Hancock site open." Boston Globe 15 Jun 2005: . [3]
- Location and size of mass dampers: telephone conversation with Richard Henige, LeMessurier Consultants, Inc.
- Oct. 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.
- ^ Pages 203-205 of Why Buildings Fall Down (1992), by Matthys Levy and Mario Salvadori, and available on Google Books [1]
- ^ Page 205 of Why Buildings Fall Down (1992), by Matthys Levy and Mario Salvadori, and available on Google Books [2]
- ^ Campbell, Robert, "Builder Faced Bigger Crisis Than Falling Windows," The Boston Globe, March 3, 1995
- ^ Boston.com / US under attack
- ^ "Financing a go for Bank of America tower in New York". Daily Commercial News and Construction Record. 2009-07-02. http://www.dcnonl.com/article/id34333. Retrieved on 2009-07-02.
- ^ http://www.boston.com/business/ticker/2009/03/hancock_tower_s.html Hancock Tower sells for $660m at auction
See also
- 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
External links
- John Hancock Tower in the Structurae database
- Images of the John Hancock Tower by Mary Ann Sullivan
- library-towers: John Hancock Tower
- Architecture Week: "When Bad Things Happen to Good Buildings" - has pictures of plywood on the Tower
- The Perfect Skyscraper - an ode to the final example of the modernist skyscraper.
- "Builder Faced Bigger Crisis Than Falling Windows" Boston Globe article by Robert Campbell on Hancock Place's most serious structural problem.
- Boston photos shows an image of the old Hancock building reflected in the new one.
- Image of the Manulife building at 601 Congress Street
- Special Report on the Boston Globe; "The Hancock at 30" includes 4 audio slideshows
- Globe Critic, Robert Campbell, on the problems of the John Hancock Tower
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Coordinates: 42°20′57.4″N 71°04′29.2″W / 42.349278°N 71.074778°W
| Preceded by Prudential Tower |
Tallest Building in Boston 1976—Present 241m |
Succeeded by None |
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