Sarah Mildred Long Bridge

The Sarah Mildred Long Bridge is a lift bridge spanning the Piscataqua River between Portsmouth, New Hampshire, and Kittery, Maine, carrying traffic of U.S. Route 1 Bypass. An original bridge by the same name was in operation from 1940 until 2016. A replacement span opened in March 2018.

Sarah Mildred Long Bridge
Seen from the New Hampshire side
Coordinates 43°05′09″N 70°45′39″W
Carries
US 1 Byp.
CrossesPiscataqua River
LocalePortsmouth, NH, and Kittery, ME
Official nameSarah Mildred Long Bridge
OwnerNHDOT & MaineDOT
Maintained byMaine-New Hampshire Interstate Bridge Authority
Characteristics
DesignConcrete lift bridge
Total length2,800 feet (850 m)[1]
Longest span300 feet (91 m)[1]
No. of lanesTwo
Rail characteristics
No. of tracksOne
Track gaugeStandard
History
DesignerHardesty & Hanover
Engineering design byFigg Engineering
Constructed byCianbro Corp.
OpenedMarch 30, 2018

History

The original Sarah Mildred 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.[2] The bridge was the direct result of the work of the Maine-New Hampshire Interstate Bridge Authority, which had been formed in 1937.[3] The major goal of the bridge project was to relieve congestion in downtown Portsmouth and Kittery, where U.S. Route 1 crossed the river via the Memorial Bridge, which had opened in 1923. The bridge was completed in 1940, a decade and a half before the United States embarked on construction of an ambitious Interstate Highway System.

Original bridge
Original bridge
The original Sarah Mildred Long Bridge, as seen from Kittery, ME
Coordinates43.0859°N 70.76091°W / 43.0859; -70.76091
Carries
US 1 Byp.
CrossesPiscataqua River
LocalePortsmouth, NH, and Kittery, ME
Official nameSarah Mildred Long Bridge
Maintained byMaine-New Hampshire Interstate Bridge Authority
ID number021702510010800[4]
Characteristics
DesignSteel truss lift bridge
Total length854.7 m (2,804 ft)
Width9.1 m (29.9 ft)
Clearance above5.09 m (16.7 ft)
Clearance below41 m (134.5 ft) (Lift span open)
History
OpenedNovember 8, 1940[5]
ClosedAugust 24, 2016
Statistics
Daily traffic14,000 (2014)
14,900 (1990)

The original Sarah Mildred Long Bridge was a double-deck truss bridge, with a road deck above and a railroad bed below. Upon its dedication in 1940 the structure 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 who rose from a secretary at its creation in 1937 to executive director.[6]

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.

From 1960 until 1972, the U.S. Route 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 the decades leading to the bridge's closure, vehicular traffic had been reduced to just two lanes.

On October 12, 1989, a worker was killed when he was riding on a counterweight as the bridge closed and he was crushed against the bridge's superstructure.[7][8]

On April 1, 2013, a large tanker struck the bridge, causing severe structural damage and leading to a temporary closure of vehicular traffic.[9] As the original Memorial Bridge had been closed in October 2011 and its replacement was under construction, the Piscataqua River Bridge was the only bridge between Kittery and Portsmouth remaining open. The bridge was repaired and re-opened to vehicle traffic on May 13, 2013.[10]

On August 21, 2016, the bridge 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,[11][12] and with NHDOT and MaineDOT 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.[11] The premature closure of the bridge was announced on August 24, 2016.[13]

Major demolition began with the overnight removal of the center span on October 14, 2016.[14] Removal of the bridge's towers followed, with a goal of removing both towers by November 18, 2016,[15] completed in April 2017.

Railroad

The railroad track that ran 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.[16] In addition to replacing a vehicular span, the bridge absorbed the traffic of a railroad trestle located just upriver which had collapsed on September 10, 1939.[17] 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,[18] sending B&M engine No. 3666 and a baggage car to the bottom of the river, where they remain.[19]

The tracks led to Kittery Junction, at which point one route split off towards York, Maine, on the York Harbor and Beach Railroad, while the other fork led to the Portsmouth Naval Shipyard in Kittery. The York Harbor and Beach branch was abandoned in 1925,[20] leaving only the shipyard branch still in service. That branch is primarily used for the transportation of nuclear materials.[21]

Present bridge

Construction of a $158.5 million replacement bridge began in January 2015, scheduled to open to traffic in September 2017. The original bridge had been set to close in November 2016,[22] but was moved up to August 21, 2016, by a mechanical problem that would have cost $1 million to repair.[12][13][11]

The new structure was designed by a joint venture of Hardesty & Hanover and Figg Engineering and constructed by Cianbro Corp. Rather than being constructed of structural steel, the bridge employs cantilevered, post-tensioned concrete spans, allowing eleven fewer piers than the original and an improved ability to absorb ship impact. Its vertical clearance of 56 feet (17 m) when closed to "IC-standard" is approximately 35 feet (11 m) higher than the original bridge, allowing an estimated 68% fewer openings.[11] The bridge deck also has 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.[23] The result is a dual-purpose single 300-foot (91 m) lift span[24] with an integrated set of rails, which lowers to railroad level when rail traffic must cross.

The new bridge was scheduled to open on September 1, 2017, but construction delays pushed this back into 2018. Maine and New Hampshire's DOT officials maintain the bridge was "commissioned" in late January 2018 following several simulated lifting scenarios, allowing the states to take possession.[25] The replacement bridge was officially opened on March 30, 2018.[26][27]

In March 2019, the project was recognized as New Hampshire's most outstanding engineering achievement of the prior year by the American Council of Engineering Companies (ACEC).[28] The project was also one of 16 finalists for ACEC's national award.[29]

Original bridge

Present bridge
  • Seen from the Maine side
  • Incomplete rail bed as of April 2018
  • Bridge and ramps, from the New Hampshire side
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See also
  •  Transport portal
  •  Engineering portal

References
  1. "Sarah Mildred Long Bridge Replacement". cianbro.com. Retrieved April 2, 2018.
  2. "Summary of The Sarah Mildred Long Bridge: A History of the Maine-New Hampshire Interstate Bridge from Portsmouth, New Hampshire, to Kittery, Maine". nh.gov. Retrieved October 2, 2006.
  3. "Bill for New Bridge Signed by President". The Portsmouth Herald. Portsmouth, New Hampshire. July 29, 1937. p. 1. Retrieved March 31, 2018 – via newspapers.com.
  4. Nationalbridges.com. "National Bridge Inventory Bridges - 021702510010800". Archived from the original on September 27, 2007. Retrieved September 29, 2006.
  5. "New Interstate Bridge Opened". Fitchburg Sentinel. Fitchburg, Massachusetts. AP. November 8, 1940. p. 4. Retrieved March 31, 2018 – via newspapers.com.
  6. "Portsmouth Herald Obituaries from: Tuesday, March 2, 2004". Archived from the original on April 27, 2006. Retrieved October 2, 2006.
  7. "FIRM CITED BEFORE WORKER'S DEATH". The Boston Globe. October 25, 1989. p. 33. Retrieved March 31, 2018 – via pqarchiver.com.
  8. "Bridge operator places blame on victim". The Burlington Free Press. Burlington, Vermont. AP. October 21, 1989. p. 15. Retrieved March 31, 2018 – via newspapers.com.
  9. "Sarah Long Bridge sustains 'severe structural damage' in crash, DOT says; Bridge closed to vehicular traffic after incident". WMUR-9. Retrieved April 2, 2013.
  10. McDermott, Deborah (May 14, 2013). "Sarah Mildred Long Bridge reopens ahead of schedule". Seacoast Online. Retrieved August 24, 2016.
  11. "A Maine-N.H. Lift Span Retires Early Due to Stuck Sheave". Engineering News-Record. bnp media. September 5–12, 2016.
  12. DeCosta-Klipa, Nik. "New Hampshire lift bridge to Maine stuck in raised position, may not ever come down". Boston Globe. Retrieved August 23, 2016.
  13. "Sarah Long Bridge permanently closed to traffic". WGME-TV. August 24, 2016. Retrieved August 24, 2016.
  14. Tranchemontagne, Cam. "DOT Crews remove middle section of Sarah Mildred Long Bridge". WMUR-TV. Retrieved October 22, 2016.
  15. Early, Brian. "Removal of Sarah Long Bridge's lift towers begins". Seacoast Online. Seacoast Media Group. Retrieved October 22, 2016.
  16. "Eliot History Time Line". Old Berwick Historical Society. March 16, 2001. Retrieved March 31, 2018.
  17. "Train Wreck Takes Two Lives". The Portsmouth Herald. Portsmouth, New Hampshire. September 11, 1939. p. 1. Retrieved March 31, 2018 – via newspapers.com.
  18. "Boston & Maine Train Accident 1939 Portsmouth NH". Retrieved March 31, 2018 – via YouTube.
  19. "TrainWreck #3666, in the Piscataqua River, NH". Retrieved March 31, 2018 – via YouTube.
  20. "York Beach Branch is to be Closed by B&M Next Month". The Portsmouth Herald. Portsmouth, New Hampshire. May 15, 1925. p. 1. Retrieved March 31, 2018 – via newspapers.com.
  21. "Cianbro Prepares for Milestone Project to Replace Sarah Mildred Long Bridge". cianbro.com. September 26, 2014. Retrieved March 31, 2018.
  22. Nadeau, Gregory (January 6, 2015). "Breaking ground: A new year, a new bridge". FHWA. US Government. Archived from the original on November 19, 2016. Retrieved August 24, 2016.
  23. Koeing, Seth (September 25, 2014). "States agree on price for Kittery-Portsmouth bridge replacement". Bangor Daily News. Retrieved September 25, 2014.
  24. "Sarah Mildred Long Bridge Replacement, New Hampshire". roadtraffic-technology.com. Retrieved March 31, 2018.
  25. Portsmouth Herald Staff (February 9, 2018). "State officials rebut 'rumors' that new $170M bridge is unsafe". Bangor Daily News. Retrieved February 9, 2018.
  26. "New bridge between Maine, New Hampshire opens to traffic". Boston.com. AP. March 30, 2018. Retrieved March 31, 2018.
  27. LaCasse, Alex (March 30, 2018). "Sarah Long Bridge opens to traffic amid dispute". seacoastonline.com. Retrieved March 31, 2018.
  28. "Sarah Mildred Long Bridge Wins Top Prize at ACEC NH Engineering Excellence Awards Ceremony". hardestyhanover.com. March 28, 2019. Retrieved July 11, 2019.
  29. "2019 Gala Evening". American Council of Engineering Companies. May 7, 2019. Retrieved July 11, 2019 – via docs.acec.org. Cite journal requires |journal= (help)

Further reading
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