Sarah Mildred Long Bridge

Sarah Mildred Long Bridge

Sarah Mildred Long Bridge seen from Kittery, ME
Coordinates 43°05′09″N 70°45′39″W / 43.0859°N 70.76091°W / 43.0859; -70.76091Coordinates: 43°05′09″N 70°45′39″W / 43.0859°N 70.76091°W / 43.0859; -70.76091
Carries US 1 Bypass
Crosses Piscataqua River
Locale Portsmouth, NH, and Kittery, ME
Official name Sarah Mildred Long Bridge
Maintained by Maine-New Hampshire Interstate Bridge Authority
ID number 021702510010800[1]
Characteristics
Design Steel Truss Lift Bridge
Total length 854.7 m (2,804 ft)
Width 9.1 m (29.9 ft)
Clearance above 5.09 m (16.7 ft)
Clearance below 41 m (134.5 ft) (Lift span open)
History
Opened 1940
Closed August 24, 2016
Statistics
Daily traffic 14,000 (2014)
14,900 (1990)

The Sarah Mildred Long Bridge was a lift bridge that carried the US 1 Bypass over the Piscataqua River between Portsmouth, New Hampshire, and Kittery, Maine. The bridge was a double-deck truss bridge, with the US 1 Bypass road deck above and a railroad bed below.

The bridge featured two separate movable spans. While the main lift span and its towers was the primary moving feature, the second moving span was apparent only to water and rail traffic. On the north side of the bridge, the first non-trussed section of rail bed lifted up and moved south as a retractable bridge, coming to rest on top of the rail tracks inside the truss. This created a waterway large enough for most recreational boats to pass through without the need for interruption of automobile traffic on the bridge.

The bridge was scheduled to close in November 2016 and construction of a replacement, scheduled to open to traffic in September 2017, began in January 2015.[2] A mechanical problem that would have cost $1 million to repair resulted in the early closure of the bridge on August 21, 2016.[3][4][5]

History

Completed in 1940, the bridge is the second to carry motor vehicle traffic between Maine and New Hampshire at Portsmouth, and replaced a river crossing dating from 1822.[6] The bridge was the direct result of the work of the Maine-New Hampshire Interstate Bridge Authority, which had been formed in 1937. The major goal of the bridge project was to relieve congestion in downtown Portsmouth and Kittery, where US 1 crossed the river via the Memorial Bridge, which had opened in 1923.

From 1960 until 1972, the bridge, along with the US 1 Bypass north of the Portsmouth Circle, filled a gap in Interstate 95, which had been designated along both the New Hampshire Turnpike and the Maine Turnpike. Although most of the bypass is four lanes wide, the bridge itself originally had only a three-lane roadbed, with traffic on the center lane switching direction depending on load (the bridge has since been reduced to just two lanes). This, combined with being a drawbridge, placed the bridge far below Interstate highway standards. The turnpikes, and therefore I-95 in the two states, did not directly connect until the opening of the Piscataqua River Bridge and the extensions of I-95 leading to it in the early 1970s.

On April 1, 2013, a large tanker ship struck the bridge, causing "severe structural damage" and leading to the bridge being temporarily closed to vehicular traffic.[7] The I-95 Piscataqua River Bridge was the only Portsmouth bridge over the Piscataqua remaining open.

The bridge was repaired and re-opened to vehicle traffic on May 13, 2013.[8]

On August 21, 2016, the bridge became stuck in the closed position due to a mechanical failure of a sheave and thrust block in the south tower. The failures were due to stress caused by the shifting of a trunnion. On August 22, officials managed to partially raise the bridge to allow ship traffic to pass per federal law, which requires ship traffic be given priority over road traffic. It was deemed unsafe to further operate the bridge in its current condition and will be left as is until demolished.[5][3] It was determined by NHDOT and MDOT officials that the repairing the bridge would cost $1 million and take at least six weeks. As the scheduled permanent closure was just four weeks after the earliest possible re-opening, it was decided that the bridge would not be repaired. Its demolition was started earlier than originally planned.[5] The premature closure of the bridge was announced on August 24, 2016.[4]

Major demolition of the bridge started in October 2016, with the overnight removal of the center span on October 14, 2016.[9] Removal of the bridge's towers then began, with a goal of removing both towers by November 18, 2016.[10]

Railroad

The railroad track that runs across the bridge was originally part of the Boston & Maine Railroad, and connected to South Berwick, Maine, via an easement that is now Route 236. The bridge replaced a railroad trestle that was located just upriver. The trestle collapsed on September 10, 1939, sending the engine (B&M #3666) and baggage car to the bottom of the river, where they remain. The trestle had been weakened when a caisson used in the construction of the new bridge dragged its anchor cables, which pulled out several of the trestle's bents.

Currently, the tracks lead only to the Portsmouth Naval Shipyard in Kittery, and are used for the transportation of nuclear materials.

Naming

For many years, the bridge was simply known as the Maine-New Hampshire (Interstate) Bridge. In 1987, the bridge was renamed to honor Sarah M. Long, who had been an employee of the Maine-New Hampshire Interstate Bridge Authority for 50 years. Starting with the agency in 1937 when the Authority was created, Ms. Long filled a number of positions, from secretary to executive director.[11]

Due to its location in Portsmouth Harbor between the Memorial Bridge and the Piscataqua River Bridge, the Sarah Mildred Long Bridge is sometimes simply referred to as "the middle bridge" or "the old toll bridge". It has also been called the "Dime Bridge", in reference to the amount paid when it was a toll bridge.

Replacement

A replacement bridge is under construction by contractor Cianbro Corp. It was designed by a joint venture of Hardesty & Hanover and Figg Engineering. The replacement will be higher than the current bridge (with 56 feet of vertical clearance when closed), allowing for more ship traffic to pass underneath without opening the bridge. This height allows for 68% fewer openings than the old bridge required.[5] It will have 11 fewer piers in the river, as well as an improved collision system in the event of a ship impacting it. The bridge deck will also have wider shoulders for bicycles. Maine and New Hampshire officials have negotiated a cost of $158.5 million with Cianbro, to conduct the work, which began early in 2015. $25 million was awarded by the U.S. Department of Transportation for the railroad portion of the work.[12]

See also

References

  1. ↑ Nationalbridges.com. "National Bridge Inventory Bridges - 021702510010800". Retrieved 2006-09-29.
  2. ↑ Nadeau, Gregory (January 6, 2015). "Breaking ground: A new year, a new bridge". FHWA. US Government. Retrieved August 24, 2016.
  3. 1 2 DeCosta-Klipa, Nik. "New Hampshire lift bridge to Maine stuck in raised position, may not ever come down". Boston Globe. Retrieved August 23, 2016.
  4. 1 2 "Sarah Long Bridge permanently closed to traffic". WGME-TV. August 24, 2016. Retrieved August 24, 2016.
  5. 1 2 3 4 "A Maine-N.H. Lift Span Retires Early Due To Stuck Sheave". Engineering News-Record. bnp media. September 5–12, 2016.
  6. ↑ nh.gov. "Summary of The Sarah Mildred Long Bridge: A History of the Maine-New Hampshire Interstate Bridge from Portsmouth, New Hampshire, to Kittery, Maine". Retrieved 2006-10-02.
  7. ↑ "Sarah Long Bridge sustains 'severe structural damage' in crash, DOT says; Bridge closed to vehicular traffic after incident". WMUR-9. Retrieved April 2, 2013.
  8. ↑ McDermott, Deborah (May 14, 2013). "Sarah Mildred Long Bridge reopens ahead of schedule". Seacoast Online. Retrieved August 24, 2016.
  9. ↑ Tranchemontagne, Cam. "DOT Crews remove middle section of Sarah Mildred Long Bridge". WMUR-TV. Retrieved 22 October 2016.
  10. ↑ Early, Brian. "Removal of Sarah Long Bridge's lift towers begins". Seacoast Online. Seacoast Media Group. Retrieved 22 October 2016.
  11. ↑ "Portsmouth Herald Obituaries from: Tuesday, March 2, 2004". Retrieved 2006-10-02.
  12. ↑ Seth Koeing (September 25, 2014). "States agree on price for Kittery-Portsmouth bridge replacement". Bangor Daily News. Retrieved September 25, 2014.
This article is issued from Wikipedia - version of the 10/22/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.