asphaltum. It became operational in 1900. A water main for direct supply to Ryde was completed in 1909. For the first time, this allowed water to bypass the Potts Hill screening chamber. It would be screened instead in a single chamber that had been added to the Pipehead Basin in c.1903-5. A Venturi Meter was added to the Ryde main in c.1906 and a small valve house was constructed above it. From 1902 to 1912 the Lower Canal was relined and the level of water was raised by 1.5m, increasing the canal's capacity by approximately 75%. The Potts Hill screening chamber found difficulty coping with the increased supply of water and it became a "major hold up point in the water supply network". In order to resolve this problem a new screening facility was built at the Pipehead Site - with 3 Pipehead Basins completed in 1913, 1918 and 1928–9. The Potts Hill screening station was then dismantled. Cranes were introduced to operate the screening at Pipehead. These included the earliest crane (a transversing jib crane with an oil motor) possibly dating to 1909, a new travelling crane which was in operation by 1915 and a locomotive crane which was installed in 1916. After electricity powered the site in 1917 these cranes were converted to electric power and by 1922 there were 4 cranes in operation on the site. A third water supply main from Pipehead to Potts Hill, Main No. 3, was completed in 1925. It was constructed from electrically welded steel pipes with collars and "full-run" lead joints. However the Pipehead to Potts Hill mains were considered so silted that, in 1926, they had to be relined. Supply was again being amplified to meet consumer demand and a new temporary woodstave main was proposed. The preference for woodstave over steel was intended to avoid the delays anticipated by the need to obtain pipes. This new main was completed by the end of 1927. With supply still being amplified in 1929 the Chief Engineer proposed construction of a 72" water supply main between the Upper Canal and Pipehead. Work began on the new main in 1931 but the Depression interrupted the project. Work resumed in 1933 under a special unemployment relief programme and the main was completed by 1937. The temporary woodstave main ceased to operate in 1938 and was gradually dismantled and/or filled with sand from 1939 to