| Summary : Unique cast iron canal lock on the Shropshire Union Canal by Thomas Telford in 1828, and one of his last major works. it was built of iron to avoid acute water loss in unstable substrate. It is constructed of flanged plates and anchored to piles of H-section., 12 feet deep. Additional piles support the hinge plates of the lower gates. Plate joints within the lock basin are protected by rubbing strakes. It is believed to have superseded a stone lock which proved too heavy for the unstable ground. It is estimated that the iron lock weighs about 10% of the weight of a conventional lock on the Ellesmere Canal. |