Strand Jacks: Development as Versatile Tool for Moving Large Structures

Abstract

The use of strand jacks in heavy lifts is steadily increasing as clients come to recognize that this very efficient equipment can facilitate traditional construction methods and can enable entirely new construction methods. These technical advantages can provide quality improvements, cost benefits, and/or increased safety. Properly purpose-designed heavy-lift strand jacks, in contrast to prestressing jacks, must allow fully remove operation for lifting or lowering over long distances. They must allow lifting or lowering operations to be stopped safely and independent of hydraulic pressure at any time and for any period of time. They must be fail-safe; that is, any loss of hydraulic pressure must result in immediate, automatic mechanical gripping of the load at any stage of the lifting or lowering cycle. Strand jacks can be used for roof lifts, large structures, and many industrial applications. Designers and construction engineers should consider strand jacks as a proven means to improve efficiency, lower costs, and utilize high safety margins when lifting heavy loads.