1. 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.with construction taking six years and costing €501 million.The aqueduct's tough structure incorporates 24,000 tonnes of steel and 68,000 cubic meters of concrete.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.
2.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.
3.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.
