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. A double-deck truss bridge, it carried the US 1 Bypass road deck above and a railroad bed below.

The bridge featured two separate movable spans, the central auto-bearing main lift and a retractable bridge for rail traffic near the Kittery shore. When not in use, the rail span lifted up and retracted south atop its own tracks inside the trusswork. The main span lifted on an as-needed basis for ocean-going commercial traffic, and on a varying set schedule for recreational craft unable to pass beneath the rail span, which was left in an open position by default to accommodate small boats and minimize interruption of auto traffic caused by raising the lift.

Construction of a replacement bridge began in January 2015, scheduled to open to traffic in September 2017. The Sarah Long was originally set to close in November 2016,[2] but a mechanical problem that would have cost $1 million to repair moved this up to August 21, 2016.[3][4][5]

History

The Sarah Long bridge was the third span to carry motor vehicle traffic between Maine and New Hampshire at Portsmouth, replacing a river crossing at its location 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. The Sarah Long was completed in 1940, a decade and a half before the United States embarked on construction of an ambitious Interstate Highway System.

From 1960 until 1972 the US 1 Bypass filled a gap in Interstate 95, linking traffic traveling the otherwise unconnected New Hampshire Turnpike and Maine Turnpike. Although most of the bypass is four lanes wide, the bridge had only a three-lane roadbed, with traffic on the center lane originally switching direction depending on load. This, combined with being a drawbridge, placed the bridge far below Interstate Highway standards. The turnpikes, and I-95, did not directly connect until the opening of the "high level" Piscataqua River Bridge and the extensions of I-95 leading to it in the early 1970s.

In recent decades the Sarah Long had been reduced to just two traffic lanes. On April 1, 2013, a large tanker struck the bridge, causing severe structural damage and leading a temporary closure to vehicular traffic.[7] With a replacement Memorial Bridge under construction, the I-95 span was the only bridge over the Piscataqua at Portsmouth remaining open.

The Sarah Long was repaired and re-opened to vehicle traffic on May 13, 2013.[8] On August 21, 2016, it became stuck in the closed position due to a mechanical failure after a shift in one of its trunnions caused a sheave and thrust block in the south tower to jam. On August 22, officials managed to partially raise the main span to allow shipping to pass under, which is given priority by federal law over road traffic. It was deemed unsafe to resume regular lifting,[5][3] and with NHDOT and MDOT officials determining repairs would cost $1 million and take at least six weeks (and permanent closure just four weeks after the earliest possible re-opening), a decision was made to leave the span partially open until demolition.[5] The premature closure of the bridge was announced on August 24, 2016.[4]

Major demolition began the overnight removal of the center span on October 14, 2016.[9] Removal of the bridge's towers followed, with a goal of removing both towers by November 18, 2016,[10] completed in April 2017.

Railroad

The railroad track that runs across the bridge was originally part of the Boston & Maine Railroad, which connected to South Berwick, Maine, via an easement that is now Maine Route 236. In addition to replacing a vehicular span, the Sarah Long absorbed the traffic of a railroad trestle located just upriver which had collapsed on September 10, 1939. It 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, sending B&M engine #3666 and a baggage car to the bottom of the river, where they remain.

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

Name

Upon its dedication in 1940 the Sarah Long was simply known as the Maine-New Hampshire Bridge, later the Maine-New Hampshire (Interstate) Bridge. It was renamed in 1987 to honor Sarah Mildred Long, a 50-year employee of the Maine-New Hampshire Interstate Bridge Authority. Starting with the authority at its creation in 1937, Ms. Long rose 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 by the area's elder residents as "the old toll bridge". To them it is also known as the "Dime Bridge", in reference to its original toll.

Replacement

A $158.5 million replacement bridge is under construction by contractor Cianbro Corp. It was designed by a joint venture of Hardesty & Hanover and Figg Engineering. The replacement's 56 feet (17 m) of vertical clearance when closed will be approximately 35 feet (11 m) higher than the Sarah Long's, allowing an estimated 68% fewer openings.[5] Heavily employing cantilevered, post-tensioned concrete spans, it will have eleven fewer piers and an improved ability to absorb ship impact. The bridge deck will also have wider shoulders for bicycle lanes. An award of $25 million was made by the U.S. Department of Transportation for the railroad portion of the work, reflecting its role in supporting the Portsmouth Naval Shipyard downriver.[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.
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