The Seal Island Bridge is a bridge located in
Victoria County Victoria County is the name of several locations:
In Australia:
*Victoria County, Western Australia
* County of Victoria, South Australia
In Canada:
* Victoria County, New Brunswick
* Municipality of the County of Victoria and the eponymous histo ...
,
Nova Scotia
Nova Scotia ( ; ; ) is one of the thirteen provinces and territories of Canada. It is one of the three Maritime provinces and one of the four Atlantic provinces. Nova Scotia is Latin for "New Scotland".
Most of the population are native Eng ...
. It is the third longest bridge span in the
province
A province is almost always an administrative division within a country or sovereign state, state. The term derives from the ancient Roman ''Roman province, provincia'', which was the major territorial and administrative unit of the Roman Empire ...
.
The bridge is a
through arch design and crosses the Great Bras d'Or channel of
Bras d'Or Lake
Bras d'Or Lake (Mi'kmaq language, Mi'kmawi'simk: Pitupaq) is an irregular estuary in the centre of Cape Breton Island in Nova Scotia, Canada. It has a connection to the open sea, and is tidal. It also has inflows of fresh water from rivers, ma ...
, connecting
Boularderie Centre,
Boularderie Island Boularderie Island (pronounced "bull-awn-dree") is an island separating the Cabot Strait from Bras d'Or Lake on the eastern coast of Cape Breton Island, Nova Scotia, Canada. It takes its name from Louis-Simon le Poupet de la Boularderie, who was g ...
on the south side with
New Harris,
Cape Breton Island
Cape Breton Island (french: link=no, île du Cap-Breton, formerly '; gd, Ceap Breatainn or '; mic, Unamaꞌki) is an island on the Atlantic coast of North America and part of the province of Nova Scotia, Canada.
The island accounts for 18. ...
on the north side.
Construction
Construction of the Seal Island Bridge began in 1960 as part of the
Trans-Canada Highway
The Trans-Canada Highway ( French: ; abbreviated as the TCH or T-Can) is a transcontinental federal–provincial highway system that travels through all ten provinces of Canada, from the Pacific Ocean on the west coast to the Atlantic Ocean o ...
project. The bridge, officially known as the Great Bras d'Or Crossing, was completed in 1961
at a cost of $4,652,850. The construction of of approach roads increased the total cost of the project to about $6 million. The bridge is a crucial link in the Trans Canada Highway between
Sydney
Sydney ( ) is the capital city of the state of New South Wales, and the most populous city in both Australia and Oceania. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about towards the Blue Mountain ...
and
Baddeck
Baddeck () is a village in northeastern Nova Scotia, Canada. It is situated in the centre of Cape Breton, approximately 6 km east of where the Baddeck River empties into Bras d'Or Lake.
Local governance is provided by the rural municipality ...
, carrying more than 7,500 vehicles a day in peak periods.
[
][
] The structure carries two traffic lanes of
Highway 105 and was originally constructed with a pedestrian sidewalk on each side.
The bridge crosses part of the channel on a causeway connecting the north shore of the channel to Seal Island, a small wooded island. The structure consists of eight steel box truss spans, three simply supported approach spans, two simply-supported splay spans, and a three-span continuous main span that consists of two side spans and a centre arch span.
[
] The steel structure is supported on tall reinforced concrete piers, armoured with cut stone at the waterline.
Closures due to wind
Due to the bridge's height and location in a deep valley that can funnel winds, the Seal Island Bridge occasionally is closed to high-sided vehicles such as
transport truck
A truck or lorry is a motor vehicle designed to transport cargo, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construction ...
s. There have been a number of incidents on the bridge over the years with winds toppling transport trucks.
At times these closures can last for a number of hours, causing traffic to back up.
RCMP
The Royal Canadian Mounted Police (RCMP; french: Gendarmerie royale du Canada; french: GRC, label=none), commonly known in English as the Mounties (and colloquially in French as ) is the federal and national police service of Canada. As poli ...
will stop high-sided vehicles at the bridge and inform they cannot cross. At times as many as 15 to 20 transport trucks can be lined up, waiting for conditions to improve so they can make the crossing.
Controversy
The location of the bridge had proven controversial. It replaced two
ferry
A ferry is a ship, watercraft or amphibious vehicle used to carry passengers, and sometimes vehicles and cargo, across a body of water. A passenger ferry with many stops, such as in Venice, Italy, is sometimes called a water bus or water taxi ...
services crossing the Great Bras d'Or; one at the northeastern end between
New Campbellton-
Big Bras d'Or, and the other at the southwestern end at
Big Harbour-
Ross Ferry.
For political reasons, it was decided to place the bridge halfway between the two ferry services on account of an outcry by communities fearing the loss of their transportation links. Unfortunately, this required an extensive modification to the Trans-Canada Highway route on the eastern slope of
Kelly's Mountain
Kellys Mountain is a mountain located in Victoria County, Nova Scotia, Canada. The Trans-Canada Highway winds its way up the mountain via Route 105. It is known for both its scenic view from the top and its steep slope on both sides of the mount ...
( high), resulting in a 180° "switchback".
A safer alternative to continue the highway further east on a gradual descent of Kelly's Mountain toward New Campbellton, crossing at the northern end of the Great Bras d'Or channel was rejected. Likewise, a route between
Beinn Bhreagh
( ) is the name of the former estate of Alexander Graham Bell, in Victoria County, Nova Scotia. It refers to a peninsula jutting into Cape Breton Island's scenic Bras d'Or Lake approximately southeast of the village of Baddeck, forming the so ...
and
Kempt Head at the extreme southwestern end of the channel (much wider waterway but avoiding Kelly's Mountain altogether) was never considered. A number of serious accidents have occurred on Kelly's Mountain and at the switchback at the base of the grade over the years, as many as six or seven accidents taking place in some years.
Deck replacement
By 2001, it was found the existing cast-in-place concrete bridge deck was in poor condition. Forty years of wear and tear from traffic as well as exposure to wind and salt spray necessitated a major overhaul of the Seal Island Bridge. The road deck needed complete replacement, and the steel truss work needed reinforcement. Engineers thoroughly inspected the rest of the bridge structure and found it to be sound and safe.
[
]
A major deck replacement project was undertaken. Over the next three years, the original cast-in-place concrete bridge deck was removed and replaced using full-depth, precast, prestressed, half-deck width concrete panels. It was necessary to complete one lane at a time, starting with the south lane, leaving the other deck in place so the bridge could continue to be used for vehicular traffic. Construction was completed with minimal traffic disruptions, and the bridge remained open to single lane traffic throughout construction, with the exception of three, six-hour overnight closures planned per week. This project added several decades to the useful life of the bridge.
The new high performance precast concrete deck system is much more durable than conventional systems since it is less permeable and crack-free under service load conditions. The deck system adopted is significantly lighter than a conventional cast-in-place concrete deck system. This has resulted in considerable savings in the amount of truss reinforcement required, while providing sufficient mass and stiffness for damping purposes.
At the same time the guard rails (traffic barriers) were replaced over the entire length of the bridge, with the new guard rails set inside the main bridge trusses to better protect them from vehicle impact. Unfortunately, this made the new bridge deck too narrow to retain the sidewalks, so they were not replaced. However, this modification did result in wider traffic lanes. The overall cost of the bridge deck reconstruction was $15 million.
There are now "No pedestrian traffic" signs on each end of the bridge.
Awards
On April 20, 2004, it was announced the Seal Island Bridge Reconstruction Project had won the Lieutenant Governor's Award for Engineering Excellence. The Department of Transportation and Public Works shared the honours with consultants CBCL Limited of Halifax for the major overhaul of the province's third largest bridge.
Gallery
File:DGJ 4883 - Seal Island Bridge.jpg, The Seal Island Bridge
File:Seal Island Bridge in Fall.JPG, The Seal Island Bridge, viewed from the Bras d'Or look off on Kelly's Mountain
File:Great Bras d'Or (Seal Island) Bridge.jpg, The MV ''Algoport'' passing under the Seal Island Bridge
See also
*
List of bridges in Canada
This is a list of bridges and viaducts in Canada, including those for pedestrians and vehicular traffic.
Historical and architectural interest bridges
There are only a few covered bridges left in Canada compared to all those that were built in t ...
References
External links
Structurae: Seal Island Bridge (1961)Highway Cameras - Seal Island BridgeBoularderie Island Historical Society - Photos of the Seal Island Bridge Under Construction, 1960
{{Commons category
Road bridges in Nova Scotia
Transport in Victoria County, Nova Scotia
Buildings and structures in Victoria County, Nova Scotia
Bridges on the Trans-Canada Highway
Bridges completed in 1961
Through arch bridges in Canada