Casco Bay Bridge

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Casco Bay Bridge
Casco Bay Bridge
Carries Motor vehicles and pedestrians
Crosses Fore River
Locale Portland, Maine
Design Multi-Girder Bascule
Longest span 285 feet (86.9 m) at movable span
Total length 4,748 feet (1447.2 m)
Clearance below 65 feet (19.8 m)
AADT 32,000+ vehicles per day
Opening date August 1997
Maps and aerial photos

The Casco Bay Bridge is a bascule bridge that spans the Fore River connecting South Portland and Portland, Maine.

[edit] History

It was decided upon in 1987 by the state of Maine and surrounding towns that the old Million Dollar Bridge, which was almost 70 years old, was inadequate. The deteriorating bridge, which was also a draw bridge, only had single lane traffic and the bottom and horizontal clearance was very limited. With the increase in tanker ships and increased usage of the bridge, a new one was needed. A plan drafted and construction started on the bridge in 1993 and it was completed in 1997.

[edit] Design

Casco Bay Bridge under construction. The span is much larger than its predecessor
Casco Bay Bridge under construction. The span is much larger than its predecessor

The new Casco Bay Bridge has four 12 foot (3.7 m) wide lanes, with an enclosed walking/jogging lane on the eastern side of the bridge.[1] The bridge is supported by several H-piles, which are 7 feet (2.1m meters) thick concrete cylinders, on which steel girders sit on top of.[2] The new bridge has a much higher horizontal and vertical clearance that allow larger ships to enter further up the river, with the bascule having to open less frequently. Extra precautions were taken to ensure that the bridge had sufficient pier protection, as during construction to the bridge, the existing Million Dollar Bridge was struck by the oil tanker, Julie N, which spilled several thousand barrels of oil into Casco Bay. The steel girders were painted red in order to make the bridge aesthetically pleasing.

The final cost for the Casco Bay Bridge was 130,000,000 dollars, which was the largest project undertaken by the Maine Department of Transportation.[3]

[edit] References

  1. ^ Portland-South Portland
  2. ^ http://www.modernsteel.com/Uploads/Issues/July_2000/0007_04_cascobay.pdf
  3. ^ Portland-South Portland