Water bridges are bridge-like structures that carry navigable
waterway canals over other rivers, valleys, railways or roads. Small
ships and boats ply on these waterways. The most popular water bridge is
the Magdeburg Water Bridge in Germany, the longest and the most
impressive in the world. Although aqueducts has been used for supplying cities with water
since centuries, they were not generally used for traffic until the
17th century when modern canal systems started to appear. The 662-metre
long aqueduct carrying the Canal latéral à la Loire over the River Loire
was built in 1896, and remained the longest navigable aqueduct in the
world until the 21st century, when the Magdeburg Water Bridge in Germany took the title.
Here are three of the most unusual and magnificent water bridges around the world.
Magdeburg Water Bridge
The
Magdeburg Water Bridge in Germany deserve special mention. Opened in
October 2003 and part of the Magdeburg crossing of waterways, it
connects the Elbe-Havel Canal to the Mittellandkanal, crossing over the
Elbe River. At 918 meters, it’s the longest navigable aqueduct in the
world.
The Elbe–Havel Canal and Mittelland Canal canals had previously met
near Magdeburg but on opposite sides of the Elbe, which was at a
significantly lower elevation than the two canals. Ships moving between
the two had to make a 12-kilometre detour, descending from the
Mittelland Canal through the Rothensee boat lift into the Elbe, then
sailing downstream on the river, before ascending to the Elbe-Havel
Canal through Niegripp lock. Low water levels in the Elbe often
prevented fully laden canal barges from making this crossing, requiring
time-consuming off-loading of cargo.
The reunification of
Germany and establishment of major water transport routes made the Water
Bridge a priority again. Work started in 1997, with construction taking
six years and costing €500 million. The water bridge now connects
Berlin’s inland harbour network with the ports along the Rhine river.
Pontcysyllte Aqueduct
The Pontcysyllte Aqueduct, in Wrexham
County Borough in Britain, was built between 1795 and 1805 to carry the
Ellesmere Canal over the valley of the River Dee to link the coal mines
of Denbighshire to the national canal system during the Industrial
Revolution. It was one of the world's greatest engineering achievements
of the time. For more than 200 years, it is the longest and highest
aqueduct in Britain, and currently a World Heritage Site.
The
aqueduct is 307 meter long, 3.4 meter wide and 1.60 meter deep, and
forms a part of an 18 km long aqueduct system. It consists of a cast
iron trough supported 38 meter above the river on iron arched ribs
carried on nineteen hollow masonry piers. The use of both cast and
wrought iron in the aqueduct enabled the construction of arches that
were light and strong, producing an overall effect that is both
monumental and elegant.
The economic influence of the canal for
the region was considerable during the first half of the 19th century,
enabling the rapid development of coal extraction, metal working,
limestone quarries, and the production of lime. The slate quarries of
the Welsh mountains and agriculture also benefited from the canal.
Today, the canal no longer moves coal and limestone cargoes, but is a
popular spot for tourists. Since 1954 the canal has been managed and
maintained in a navigable condition by British Waterways.
Barton Swing Aqueduct
The Barton Swing Aqueduct is a
moveable water bridge in Barton upon Irwell in Greater Manchester,
England, that carries the Bridgewater Canal across the Manchester Ship
Canal. The swinging action allows large vessels using the Manchester
Ship Canal to pass underneath and smaller narrow boats to cross over the
top. When large vessels need to pass along the Ship Canal, the
1,450-tonne and 100 meter long iron trough is rotated 90 degrees. A gate
at each end of the trough retains around 800 tonnes of water; further
gates on each bank retain water in their adjacent stretches of canal. A
similar swing bridge, but for road traffic, lies adjacent to, and
upstream of, the Barton Swing Aqueduct.
The aqueduct, which is
the first and only swing aqueduct in the world is considered a major
feat of Victorian civil engineering. Designed by Sir Edward Leader
Williams and built by Andrew Handyside of Derby, the swing bridge opened
in 1894 and remains in regular use.
Previously, the aqueduct
crossing over River Irwell was a rigid stone structure that prevented
new ships of larger dimension to pass underneath the bridge. A swinging
bridge became a necessity.
The swing aqueduct (left) in the closed position, showing the
Bridgewater canal crossing over the Ship Canal; the Barton Road Swing
Bridge is on the right.
Other notable water bridges, not included in this Top3 list are the Avon Aqueduct
- the longest and tallest canal aqueduct in Scotland and the
second-longest in the United Kingdom, after the Pontcysyllte Aqueduct,
and the Briare Aqueduct – which was the longest
navigable aqueduct in the World until the opening of the Magdeburg Water
Bridge. If you are interested, look them up on Google. If you are
visiting the United Kingdom, spare a day to visit these remarkable
achievements in civil engineering.
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