The southern system, across the less populated suburbs of London, was the smaller and easier part of the system to build. Three main sewers ran from Putney, Wandsworth and Norwood until they linked together in Deptford. At that point a pumping station lifted the effluent into the main outflow sewer, which ran to the Crossness Pumping Station on the Erith Marshes, where it was discharged into the Thames at high tide. The newly built station at Crossness was designed by Bazalgette and a consultant engineer, Charles Driver, a proponent of the use of cast iron as a building material. The building was in a Romanesque style and the interior contains architectural cast ironwork which English Heritage describe as important. The power for pumping the large amount of sewage was provided by four massive beam engines, named Victoria, Prince Consort, Albert Edward and Alexandra, which were manufactured by James Watt and Co.