Archimedes' screw pipe does not need to be perfectly watertight, as long as the amount of water being scooped with each turn is large compared to the amount of water leaking out of each section of the screw per turn. If water from one section leaks into the next lower one, it will be transferred upwards by the next segment of the screw. In some designs, the screw is fused to the casing and they both rotate together, instead of the screw turning within a stationary casing. The screw could be sealed to the casing with pitch resin or other adhesive, or
Tochmaland, Kollum containing an electrically driven Archimedes' screw was erected next to the mill. A proposal to demolish the mill was rejected by the mayor of the gemeente Kollumerland en Nieuwkruisland. 0n 30 December 1948, the mill was purchased by the gemeente. Restorations were undertaken in 1949, 1963 and 1983. since 1995, an electric motor has been installed in "Tochmaland" to drive its Archimedes' screw, and the installation in the brick shed demolished. "Tochmaland" is what the Dutch describe as an "Grondzeiler". It is a two-storey smock mill on a single-storey base. There is no stage, the sails reaching down almost to