Deer Isle Bridge
| Deer Isle Bridge | |
|---|---|
 |
|
| Coordinates | 44°17′38″N 68°41′20″W / 44.2940°N 68.6888°WCoordinates: 44°17′38″N 68°41′20″W / 44.2940°N 68.6888°W |
| Carries | Motor vehicles, pedestrians, bicycles |
| Crosses | Eggemoggin Reach |
| Locale | Deer Isle, Maine |
| Characteristics | |
| Design | Suspension |
| Longest span | 1,088 feet (329 m) |
| Clearance below | 85 feet (25.9 m) |
| History | |
| Construction end | December 31, 1938 |
| Opened | December 31, 1939 |
| Statistics | |
| Daily traffic | 123 |
The Deer Isle Bridge is a suspension bridge spanning Eggemoggin Reach in the state of Maine. The bridge is the only vehicular connection from the Maine mainland to Little Deer Isle, one of the segments that make up the island. The span was completed in March 1939 with a main span of 329 meters (1,088 ft). The bridge was designed by Holton Duncan Robinson and David Bernard Steinman. It encountered wind stability problems that were similar to those of the Whitestone Bridge and the original Tacoma Narrows Bridge, which collapsed shortly after it opened. The problems led to modifications which included numerous cable stays connecting cables to the tower and tower to the deck. The span today carries two narrow lanes of State Route 15.
A re-decking project was completed in May 2008. Repainting started in mid-2010 has been completed.
The Deer Isle-Sedgwick Bridge, named for the two townships it connects, was the first bridge built between Deer Isle and the mainland, replacing an inadequate ferry crossing system and effectively opening the island to tourism opportunities. It is notable for the innovation of its designers and contractors in creating a durable, long-span, high-level structure across a navigable arm of the Atlantic at minimal cost. Unprecedented use of prefabricated and previously used materials simplified construction and minimized costs, and much of the outdoor work was completed under poor weather conditions.
The challenges facing David B. Steinman, his firm, and their contractors were numerous. The popularity of Eggemoggin Reach as a yachting area called for a 200-foot (61 m) wide channel at midspan with a minimum 85-foot (26 m) underclearance, placing the roadway at 98.7 feet (30.1 m) above mean water level. At the same time, the depth required for foundations at this location called for minimizing the length of the approach spans. This height problem was solved by employing steep 6.5% approach grades and a fairly short 400-foot (120 m) vertical curve at the center of the main span. In this manner, the needed height was attained and the approach viaducts were kept to a minimum length.
The project was also complicated by its required early-summer completion date, meaning that much of the work had to be done during the winter and early spring months when weather conditions posed a significant challenge. Robinson and Steinman and their contractors solved this difficulty by prefabricating many of the components offsite and completing the bulk of the assembly quickly, working between high tides. Site-specific innovations in prefabrication and construction methods minimized outdoor work at the site and departed from conventional bridge-building practice. This careful consideration and planning resulted in a project completed on schedule and at low cost, despite the extreme conditions.
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