Pontcysyllte Aqueduct
52.970277777778 - 3.0877777777778Koordinaten: 52 ° 58 ' 13 " N, 3 ° 5' 16 " W
F1
River Dee
The Pontcysyllte Aqueduct [ ˌ pɔntkəsəɬte ] is designed as a navigable aqueduct trough bridge that leads to the Llangollen Canal over the valley of the River Dee between the municipalities Trevor ( Wrexham ) and Froncysyllte, Wrexham in north-east Wales. It was completed in 1805 and since then has been both the longest and highest aqueduct in Britain. It is considered a cultural monument and is first class in June 2009 on the list of UNESCO World Heritage Sites.
Construction
Built by Thomas Telford and supervised by the experienced Kanalbauingeneur William Jessop the aqueduct was part of the original Ellesmere, now named Llangollen Canal waterway and is one of the most outstanding examples of former engineering. The aqueduct is 307 m long, 3.35 m wide and 1.60 m deep. It consists of a cast iron trough, which is led 38.5 m above the river, supported by 19 hollow been walled bridge piers. The span is 16 m, respectively. Despite the concerns of many skeptics Telford was sure he had already built another cast-iron aqueduct ( the Longdon -on -Tern Aqueduct on the Shrewsbury Canal, which can be visited still today, the channel was abandoned years ago ).
The mortar used included lime, water and ox blood. The cast iron gave William Hazeldine from his factory in Shrewsbury and nearby Cefn Mawr. The cast iron plates that formed the navigable trough were produced in the foundry Plaskynaston and bolted together. To seal the connections, soaked Welsh flannel fabric was used in boiling sugar. Finally, the seams were sealed with lead. Finally, the trough was filled with water and a half years observing if water leaked out of the tank.
The opening took place after ten years of planning and construction, on 26 November 1805. It ended up costing a total of £ 47,000.
Operation
The towpath is cantilevered out on the east side on the channel, which occupies the full width of the aqueduct. The remaining fairway on the west side of the aqueduct is only a few inches wider than a narrowboat, the special type of boat for the Central English and Welsh channels. Navigation is therefore on view in the one-way operation. The users of the towpath are protected by a railing on the outside of the aqueduct. The existing holes for a possibly planned railing on the other side of the trough remained unused until today. Therefore, at only a few inches between the ending above the water surface channel trough and the helmsman of a narrowboats nothing but the prospect of a fall from almost 40 meters. After the commercial decline of the channels the early 20th century now traveled almost exclusively leisure boats, the channel system.
In the middle of the aqueduct is a valve which is opened at intervals of several years, for the maintenance of the trough. The water from the trough then crashes spectacularly in cascades into the river Dee. Previously, the aqueduct is blocked by the introduction of planks across the canal on both sides.