The Sarah Mildred Long Bridge is a
lift bridge
A vertical-lift bridge or just lift bridge is a type of movable bridge in which a span rises vertically while remaining parallel with the deck.
The vertical lift offers several benefits over other movable bridges such as the bascule and sw ...
spanning the
Piscataqua River
The Piscataqua River (Abenaki: ''Pskehtekwis'') is a tidal river forming the boundary of the U.S. states of New Hampshire and Maine from its origin at the confluence of the Salmon Falls River and Cochecho River. The drainage basin of the river ...
between
Portsmouth, New Hampshire
Portsmouth is a city in Rockingham County, New Hampshire, United States. At the 2020 census it had a population of 21,956. A historic seaport and popular summer tourist destination on the Piscataqua River bordering the state of Maine, Portsmou ...
, and
Kittery, Maine
Kittery is a town in York County, Maine, United States. Home to the Portsmouth Naval Shipyard on Seavey's Island, Kittery includes Badger's Island, the seaside district of Kittery Point, and part of the Isles of Shoals. The southernmost town i ...
, 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.
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. 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
U.S. Route 1
U.S. Route 1 or U.S. Highway 1 (US 1) is a major north–south United States Numbered Highway that serves the East Coast of the United States. It runs from Key West, Florida, north to Fort Kent, Maine, at the Canadian border, making ...
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
The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, is a network of controlled-access highways that forms part of the National Highway System in the United States. Th ...
.
Original bridge
The original Sarah Mildred Long Bridge was a double-deck
truss bridge
A truss bridge is a bridge whose load-bearing superstructure is composed of a truss, a structure of connected elements, usually forming triangular units. The connected elements (typically straight) may be stressed from tension, compression, or ...
, 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.
The bridge featured two separate movable spans, the central auto-bearing main lift and a
retractable bridge
A retractable bridge is a type of moveable bridge in which the deck can be rolled or slid backwards to open a gap while traffic crosses, usually a ship on a waterway. This type is sometimes referred to as a thrust bridge.
Retractable bridges d ...
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
Interstate 95 (I-95) is the main north–south Interstate Highway on the East Coast of the United States, running from U.S. Route 1, US Route 1 (US 1) in Miami, Miami, Florida, to the Houlton–Woodstock Border Crossing between M ...
, linking traffic traveling the otherwise unconnected
New Hampshire Turnpike and
Maine Turnpike
Interstate 95 (I-95) in the US state of Maine is a highway running from the New Hampshire state line in Kittery, to the Canadian border in Houlton. It is the only two-digit Interstate Highway in Maine. In 2004, the highway's route between P ...
. 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
The Piscataqua River Bridge is a through arch bridge that crosses the Piscataqua River, connecting Portsmouth, New Hampshire with Kittery, Maine. Carrying six lanes of Interstate 95, the bridge is the third modern span and first fixed crossing of ...
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.
On April 1, 2013, a large tanker struck the bridge, causing severe structural damage and leading to a temporary closure of vehicular traffic. 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.
On August 21, 2016, the bridge became stuck in the closed position due to a mechanical failure after a shift in one of its
trunnion
A trunnion (from Old French "''trognon''", trunk) is a cylindrical protrusion used as a mounting or pivoting point. First associated with cannons, they are an important military development.
Alternatively, a trunnion is a shaft that positions a ...
s caused a
sheave
A sheave () or pulley wheel is a grooved wheel often used for holding a belt, wire rope, or rope and incorporated into a pulley
A pulley is a wheel on an axle or shaft that is designed to support movement and change of direction of a ...
and
thrust block A thrust block, also known as a thrust box, is a specialised form of thrust bearing used in ships, to resist the thrust of the propeller shaft and transmit it to the hull.
Early thrust boxes
Early screw-propelled steamships used a 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,
and with NHDOT
The New Hampshire Department of Transportation (NHDOT) is a government agency of the U.S. state of New Hampshire. The Commissioner of NHDOT is Victoria Sheehan. The main office of the NHDOT is located in the J. O. Morton Building in Concord.
F ...
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.[ The premature closure of the bridge was announced on August 24, 2016.][
Major demolition began with the overnight removal of the center span on October 14, 2016. Removal of the bridge's towers followed, with a goal of removing both towers by November 18, 2016, completed in April 2017.
]
Railroad
The railroad track that ran across the bridge was originally part of the Boston & Maine Railroad
The Boston and Maine Railroad was a U.S. Class I railroad in northern New England. Originally chartered in 1835, it became part of what was the Pan Am Railways network in 1983 (most of which was purchased by CSX in 2022).
At the end of 1970 ...
, which connected to South Berwick, Maine
South Berwick is a town in York County, Maine, United States. The population was 7,467 at the 2020 census. South Berwick is home to Berwick Academy, a private, co-educational university-preparatory day school founded in 1791.
The town was s ...
, via an easement that is now Maine Route 236. 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. 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 No. 3666 and a baggage car to the bottom of the river, where they remain.
The tracks led to Kittery Junction, at which point one route split off towards York, Maine
York is a town in York County, Maine, United States, near the southern tip of the state. The population in the 2020 census was 13,723. Situated beside the Atlantic Ocean on the Gulf of Maine, York is a well-known summer resort town. It is home ...
, on the York Harbor and Beach Railroad, while the other fork led to the Portsmouth Naval Shipyard
The Portsmouth Naval Shipyard, often called the Portsmouth Navy Yard, is a United States Navy shipyard in Kittery on the southern boundary of Maine near the city of Portsmouth, New Hampshire.
Founded in 1800, PNS is U.S. Navy's oldest continuo ...
in Kittery. The York Harbor and Beach branch was abandoned in 1925, leaving only the shipyard branch still in service. That branch is primarily used for the transportation of nuclear materials.
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, but was moved up to August 21, 2016, by a mechanical problem that would have cost $1 million to repair.
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 cantilever
A cantilever is a rigid structural element that extends horizontally and is supported at only one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cant ...
ed, post-tensioned concrete
Prestressed concrete is a form of concrete used in construction. It is substantially "prestressed" ( compressed) during production, in a manner that strengthens it against tensile forces which will exist when in service. Post-tensioned concreted i ...
spans, allowing eleven fewer pier
Seaside pleasure pier in Brighton, England. The first seaside piers were built in England in the early 19th century.">England.html" ;"title="Brighton, England">Brighton, England. The first seaside piers were built in England in the early 19th ...
s than the original and an improved ability to absorb ship impact. Its vertical clearance of when closed to " IC-standard" is approximately higher than the original bridge, allowing an estimated 68% fewer openings.[ The bridge deck also has wider shoulders for bicycle lanes.
An award of $25 million was made by the ]U.S. Department of Transportation
The United States Department of Transportation (USDOT or DOT) is one of the executive departments of the U.S. federal government. It is headed by the secretary of transportation, who reports directly to the President of the United States and ...
for the railroad portion of the work, reflecting its role in supporting the Portsmouth Naval Shipyard
The Portsmouth Naval Shipyard, often called the Portsmouth Navy Yard, is a United States Navy shipyard in Kittery on the southern boundary of Maine near the city of Portsmouth, New Hampshire.
Founded in 1800, PNS is U.S. Navy's oldest continuo ...
downriver. The result is a dual-purpose single lift span 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. The replacement bridge was officially opened on March 30, 2018.
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). The project was also one of 16 finalists for ACEC's national award.
Gallery
Original bridge
File:Sarah Mildred Long Bridge 03.jpg, Seen from the Memorial Bridge, Piscataqua River Bridge
The Piscataqua River Bridge is a through arch bridge that crosses the Piscataqua River, connecting Portsmouth, New Hampshire with Kittery, Maine. Carrying six lanes of Interstate 95, the bridge is the third modern span and first fixed crossing of ...
behind
File:Sarah Mildred Long Bridge 04.jpg, Movable rail bed
File:Sarah Mildred Long Bridge Train.JPG, Nuclear fuel transport train leaving Kittery
File:Sarah Mildred Long Bridge 02.jpg, Seen from Portsmouth
Present bridge
File:Sarah_Mildred_Long_Bridge_(2018)_4.jpg, Seen from the Maine side
File:Sarah_Mildred_Long_Bridge_(2018)_6.jpg, Incomplete rail bed as of April 2018
File:Sarah_Mildred_Long_Bridge_(2018)_2.jpg, Bridge and ramps, from the New Hampshire side
See also
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References
Further reading
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External links
gencourt.state.nh.us
Legislation outlining the formation of the Maine-New Hampshire Interstate Bridge Authority
massroads.com
Pictures of the original bridge, including the movable rail section in the closed position, via Wayback Machine
The Wayback Machine is a digital archive of the World Wide Web founded by the Internet Archive, a nonprofit based in San Francisco, California. Created in 1996 and launched to the public in 2001, it allows the user to go "back in time" and see ...
Photographic record
of the bridge replacement, by a resident of Portsmouth
5966 Crossing Sarah Mildred Long Bridge with DODX Flat
via YouTube
YouTube is a global online video platform, online video sharing and social media, social media platform headquartered in San Bruno, California. It was launched on February 14, 2005, by Steve Chen, Chad Hurley, and Jawed Karim. It is owned by ...
Webcam
on the Memorial Bridge, providing a view of the Sarah Mildred Long Bridge
*
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, structure = Bridges
, place = Piscataqua River
The Piscataqua River (Abenaki: ''Pskehtekwis'') is a tidal river forming the boundary of the U.S. states of New Hampshire and Maine from its origin at the confluence of the Salmon Falls River and Cochecho River. The drainage basin of the river ...
, bridge = Sarah Mildred Long Bridge
, bridge signs =
, upstream = Piscataqua River Bridge
The Piscataqua River Bridge is a through arch bridge that crosses the Piscataqua River, connecting Portsmouth, New Hampshire with Kittery, Maine. Carrying six lanes of Interstate 95, the bridge is the third modern span and first fixed crossing of ...
, upstream signs =
, downstream = Memorial Bridge
, downstream signs =
Vertical lift bridges in the United States
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Road bridges in Maine
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Towers in New Hampshire
Buildings and structures in Portsmouth, New Hampshire
Bridges in Rockingham County, New Hampshire
Historic American Engineering Record in New Hampshire
Transportation buildings and structures in York County, Maine
U.S. Route 1
Bridges of the United States Numbered Highway System
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