|Zakim Bunker Hill Bridge|
Zakim Bunker Hill Bridge
|Carries||10 lanes of Interstate 93 and U.S. Route 1|
|Locale||Boston, Massachusetts, Charlestown, Massachusetts|
|Official name||Leonard P Zakim-Bunker Hill Memorial Bridge|
|Design||Hybrid Steel and Concrete Cable-stayed bridge|
|Total length||1,432 ft (436 m)|
|Width||183 ft (56 m)|
|Height||270 ft (82 m)|
|Longest span||745 ft (227 m)|
|Clearance below||40 ft (12 m)|
|Opened||March 30, 2003 (NB)
December 20, 2003 (SB)
The Leonard P. Zakim Bunker Hill Memorial Bridge, known locally as the Zakim Bridge, is a cable-stayed bridge that spans across the Charles River. This bridge connects downtown Boston, Massachusetts to the Boston neighborhood of Charlestown. This bridge carries Interstate 93 along with U.S. Route 1. The bridge features 10 lanes, four of which are southbound, six of which are northbound, while two of the northbound lanes are cantilevered off of the side of the bridge.
This bridge was built as part of the Big Dig. Which was the most expensive highway project ever undertaken by the United States, costing approximately $22 billion, nearly four times what the project was intended to cost ($6 billion, adjusted for inflation). The purpose of the project was to reroute Interstate 93 underneath the city of Boston so traffic congestion could reduce and the bridge previously in this location, the Charlestown High Bridge, along with the elevated highway that went through downtown, could be destroyed. The project took over 20 years to complete and is often considered to have been one of the biggest engineering failures in the modern age, while wasting money and managing to fall apart many times during and after construction. The Bridge is one of the few critically acclaimed aspects about the project, because of the way it manages to be aesthetically pleasing while mimicking the near-by Bunker Hill Monument, which ties the modern design with the rich history of the city.
The bridge received much fanfare upon its completion, quickly becoming an icon for the city.
The Zakim Bridge is considered to be a cable-stay bridge. In a cable stay bridge, supporting cables are run directly from the bridge towers to the bridge deck, unlike in a suspension bridge, in which cables are strung between towers only to have more supporting cables then run from the main cable to the bridge deck.
The Zakim is considered to be the widest, and the first asymmetrical cable-stay bridge in the world. The bridge carries 10 lanes with a total width of an astonishing 183 ft. The asymmetrical design is due to the two lanes which cantilever off of the east side of the bridge.
The structural components of the bridge such as the bridge deck and cables are made up of steel. While the bridge towers are composed of steel reinforced concrete.
The other half of the name is derived from the Bunker Hill Monument, which is just a half mile north-east of the bridge. The bridge towers are meant to evoke the design of the monument as a way of connecting the modern design with the rich history of the city of Boston.
When viewing a structure in the context of Structural Art, one has to take the 'Three E's' into account. The 'Three E's' consist of Efficiency, Economy, and Elegance.
- Efficiency: The use of the minimum amount of material needed to ensure that the structure safely performs its function.
- Economy: Avoidance of excessive monetary cost in the design, construction, operating and decommissioning costs of a structure. Economy should be evaluated in terms of the life-cycle cost of the structure whenever possible.
- Elegance: The structural form should be aesthetically pleasing, but should be defined and driven by engineering considerations. Thus, an elegant design is not simply one that is pleasing, but one that arises from engineering creativity, satisfies the requirements of efficiency and economy, and is also pleasing.
While the Zakim Bridge manages to display a beautiful design to most people who see it, it seems like a waste of money from an economic standpoint to have built such an extravagant bridge, where a much simpler bridge could have carried the same function.
As far as elegance, the Zakim acts as a very nice complement to an already beautiful Boston skyline. The bridge has become an icon for the city and managed to be very aesthetically pleasing to most who view it. Yet while visually appealing it is clear when considering the economy and efficiency of the structure that the bridge does not fare so well. The Leverett Circle Connector Bridge (LCCR) runs parallel to the Zakim and features a much less extravagant design. The LCCR only cost about one fifth of what the Zakim cost  . This proves that a much simpler design like the LCCR could have carried the same function that the Zakim carried without all the excess material, designing and most importantly cost. So in the context of economy and efficiency, the bridge fails.
- Massachusetts Turnpike Authority. "MTA - The Charles River Bridges". Retrieved 2006-10-19.
- "MTA - The Charles River Bridges".
- Eastern Roads. "Leonard P Zakim-Bunker Hill Memorial Bridge (I-93 and US 1)". Retrieved 2006-10-19.
- Janberg, Nicolas. "Leonard P. Zakim Bunker Hill Bridge". Structurae. Retrieved 3/12/12. Check date values in:
- "The Leonard P. Zakim Bunker Hill Memorial Bridge".