Leonard P. Zakim Bunker Hill Memorial Bridge
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The Leonard P. Zakim Bunker Hill Memorial Bridge is a cable-stayed bridge that carries eight lanes of the Interstate 93 and U.S. Route 1 concurrency, plus a two lane access ramp, across the Charles River in Boston, Massachusetts. The bridge was built as part of the Big Dig, the largest overall highway construction project in the United States. The entrance to the Thomas P. "Tip" O'Neill Jr. Tunnel, another major component of the Big Dig, is at the bridge's southern end, while north of the bridge I-93 heads toward New Hampshire and US 1 splits from the Interstate and travels northeast toward Massachusetts' north shore, crossing the Mystic River via the Tobin Bridge. The bridge replaced the Charlestown High Bridge when it opened, and is the world's widest cable-stayed bridge. The bridge is now a major landmark and major piece of the Boston skyline. It has been featured in several films recently including the 2005 version of War of the Worlds and Martin Scorsese's The Departed. It can also be briefly seen in the opening credits of the television show, Boston Legal and often serves as a backdrop for interviews. |  |
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In a cable-stayed bridge, instead of hanging the roadbed from cables
slung over towers, the cables run directly between the roadbed and the
towers. Although cable-stayed bridges have been common in Europe since
World War II, they are relatively new to North America.
The bridge concept was developed by Swiss civil engineer Christian Menn and its design was engineered by American civil engineer Ruchu Hsu with Bechtel Parson Brinckerhoff. Boston-based architect Miguel Rosales was the lead architect/urban designer and facilitated community participation during the design process. |
Neither Hsu nor
Rosales served as the designer of record for the project. The engineer
of record is HNTB/FIGG. The lead designer from HNTB was Theodore Zoli;
and W. Denney Pate from FIGG. The bridge follows a new design in which
two outer lanes are cantilevered outside the towers while another
eight lanes run through the towers. It has a striking, graceful
appearance that is meant to echo the tower of the Bunker Hill
Monument, which is within view of the bridge, and the white cables
evoke imagery of the sails of the USS Constitution.
According to the Massachusetts Turnpike Authority's web site, the bridge has an overall length of 436.5 m, a main span of 227.1 m, side spans of 81.4 m (downtown side) and 128.0 m (Charlestown side), and towers that are 82.3 m tall. winds. |
The bridge was designed to withstand
high winds. While the highest wind gusts recorded in Boston were 110
MPH, the bridge can withstand up to 400 MPH
The bridge's full name commemorates both Boston civic leader Leonard P. Zakim, who championed "building bridges between peoples", and the Battle of Bunker Hill. The bridge is commonly referred to as the "Zakim Bridge" by many local Boston newspapers, radio and television media, but many residents of the community of Charlestown and other Bostonians refer to it by its full name, "The Zakim-Bunker Hill Bridge". |
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Zakim Bridge, Sept 2001 The Leonard P. Zakim Bunker Hill Memorial Bridge is a cable-stayed bridge across the Charles River in Boston, Massachusetts. It is a replacement for the Charlestown High Bridge, an older truss bridge constructed in the 1950s, and is the world's widest cable-stayed bridge. (continued below) Photo 72, Sept 2001 |
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Zakim Bridge, July 2009 as seen from Causeway Street near North Station. The main portion of the Zakim Bridge carries four lanes each northbound and southbound of the Interstate 93 and U.S. Route 1 concurrency between the Thomas P. "Tip" O'Neill Jr. Tunnel and the elevated highway to the north. Two additional lanes are cantilevered outside the cables, which carry northbound traffic from the Sumner Tunnel and North End on-ramp. These lanes merge with the main highway north of the bridge. I-93 heads toward New Hampshire as the "Northern Expressway" and US 1 splits from the Interstate and travels northeast toward Massachusetts' north shore, crossing the Mystic River via the Tobin Bridge. The bridge and connecting tunnel were built as part of the Big Dig, the largest highway construction project in the United States. Finished in 2003, the bridge's unique styling quickly became an icon for Boston, often featured in the backdrop of national news channels to establish location, and included on tourist souvenirs. The bridge is commonly referred to as the "Zakim Bridge" and as the "Bunker Hill Bridge" by residents of nearby Charlestown. Photo 15, July 2009 |
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Zakim Bridge, July 2009 as seen from Causeway Street near North Station. Photo 16, July 2009 |
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Zachim Bridge with RR drawbridge in the foreground
Photo 34, May 2012 |
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