in Derby
DEMOLISHED IN 1970
1796 'The weir across the river Derwent, and the cast-iron aqueduct in the Holmes, being finished, there remains but little to be done, 'ere the three branches of the navigation are united, and the public let into the full enjoyment of the numerous advantages which will result from this undertaking.'[1]
The 44 ft. long single-span aqueduct carried the Derby Canal over a mill leat. The aqueduct itself was later crossed by the Cattle Market Road cast iron bridge.[2]. It was 15 ft wide and 5 ft 8" deep. Repairs were needed in 1802 because a bottom plate had 'buckled' allowing serious leakage.[3]
Designed by Benjamin Outram. It was the world's first navigable cast iron aqueduct, narrowly pre-dating Thomas Telford's 186 ft-long Longdon-on-Tern Aqueduct on the Shrewsbury Canal, (sometimes described as the world's first large-scale navigable cast iron aqueduct). The oldest currently navigable cast-iron aqueduct is Outram's Stakes Aqueduct (Stalybridge Aqueduct)[4]. The oldest surviving cast iron aqueduct is Pont-y-cafnau, but this was not navigable.