Technology
The ancient Romans also had a complex system of aqueducts, which were used to transport water across long distances. The first Roman aqueduct was built in 312 BCE. The eleventh and final ancient Roman aqueduct was built in 226 CE. Put together, the Roman aqueducts extended over 450 kilometers, but less than seventy kilometers of this was above ground and supported by arches.
Derby Canal
The Holmes Aqueduct proved to be extremely troublesome. Aqueducts up to that time had been made of stone, but several short arches would have been necessary, causing obstruction to the flow of the stream. The single-span cast iron structure that Outram devised, and completed in 1796, was the first of its kind, as it was completed a few weeks earlier than Longdon-on-Tern Aqueduct, the structure by Thomas Telford at Longdon-on-Tern on the Shrewsbury Canal.
In 1802 there was a partial failure, probably due to the sides bowing and transferring too much weight to the base where they joined to the deck. After remedial work it failed again in 1812 and was reinforced with timber baulks. Although plans were prepared for replacement in stone, it survived until 1930, when the bottom plates were replaced by a wooden base, which was sealed by puddling.