The hydraulic characteristics of Roman lead water pipes: an experimental investigation

An experimental investigation was conducted on two lengths of Roman lead water pipe excavated near Corbridge, Northumberland, England. The pipes date from approximately AD 80. One length of pipe contained a sleeve joint. The pipes were linked to a pump system using 3 D-printed connectors, and the hydraulic head loss along the pipe was measured. The pipe without a joint was used to determine a value for the wall roughness height, fitting the results to the Darcy-Weisbach equation. The wall roughness height obtained was assumed to apply to the pipe with the joint, and the additional head loss observed was then assumed to be due to the joint, allowing determination of a local loss coefficient. The pipes have a sinter encrustation, indicating that they had typically flowed partially full. Using this as an indication of water depth and deriving topographical information from the excavation report, the likely flow the pipes carried during their operational life was estimated. It was concluded that the pipe wall roughness coefficient ks was 0.9 mm, the joint local loss coefficient was 1.159, and that during operation the pipe probably carried around 17 litres/minute.