Ice adhesion to locks and dams: Past work; Future directions?

Adhesion of ice to surfaces creates problems for many industries, including aviation, hydropower, telecommunications, navigation, electrical distribution, and all forms of transportation. Specific problems at locks and dams include ice buildup on lock walls and miter gates, and spillway gate freeze up, preventing opening on short notice. At present, ice removal techniques are both costly and time-consuming. In an effort to reduce the cost, time, and physical labor associated with ice removal, much research on ice adhesion has been done. This work ranges from theoretical studies to microscopic investigations and full-scale field tests. The main focus of all of these studies is how to lower ice's adhesive strength, thus casing ice removal. Three principal methods to lower ice's adhesive strength have been pursued-electrical, chemical, and mechanical. Of the three methods, the mechanical removal of ice has received the least amount of attention. Three approaches have been taken with regard to electrical methods. They are using heaters, creating an electrical pulse that mechanically breaks the ice, and applying a direct current bias to change the ice's adhesion. The search for a low adhesive coating or material has by far received the most attention of any method pursued for lowering ice's adhesive strength. A class of chemicals containing polysiloxanes has shown promise in providing a low adhesion surface. Based on this review, we recommend that an electroexpulsion method developed for the space shuttle and a newly formulated polysiloxane be tested as to their feasibility in the lock and dam environment.