This creates a need for more difficult rigging arrangements for standing up or laying down loads and requires another pair of lifting units for long loads. Use of four cylinders gives more capacity per lifting unit. Quad Lift capacities range from 400 ton to 1,600 ton. Power Towers Boom style gantries using steel booms similar to hydraulic cranes. Two lift cylinders are located outside the boom and an additional cylinder is located inside the boom.
Power Towers are also available with a single cylinder boom style with the cylinder inside.
The single cylinder inside design is limited in capacity since it requires a much larger, more specialized cylinder that reduces the capacity as each stage of the cylinder extends. The steel booms allow for utilization of optional automatic locking devices that can hold suspended loads for long periods of time. Mobile Equipment and Forklifts Mobile lifting alternatives to conventional cranes. Lifting capacities range from 30 - 75 US tons. Work in areas too small for hydraulic or conventional cranes.