Archimedes' screw the screw and casing could be cast together as a single piece in bronze. The design of the everyday Greek and Roman water screw, in contrast to the heavy bronze device of Sennacherib, with its problematic drive chains, has a powerful simplicity. A double or triple helix was built of wood strips (or occasionally bronze sheeting) around a heavy wooden pole. A cylinder was built around the helices using long, narrow boards fastened to their periphery and waterproofed with pitch. The screw was used predominately for the transport of water to irrigation systems and for dewatering mines or other low-lying
Archimedes' screw hatcheries, where it is desirable to minimize the physical handling of fish. An Archimedes screw was used in the successful 2001 stabilization of the Leaning Tower of Pisa. Small amounts of subsoil saturated by groundwater removed from far below the north side of the tower, and the weight of the tower itself corrected the lean. Archimedes screws are also used in chocolate fountains. A "screw conveyor" is an Archimedes screw contained within a tube and turned by a motor so as to deliver material from one end of the conveyor to the other. It is particularly suitable for transport of