The jack-up system is a multipoint lifting system. A typical system setup includes four jack-up units positioned under each corner of a load. A four unit setup has a lifting capacity of 2,000 metric tons (500 tons per unit). The lifting frame of a jack-up contains four hydraulic cylinders in each corner which lift and stack steel boxes. A load is lifted in increments as boxes are slid into the system, lifted, and stacked; forming 'lifting towers'. A jack-up system is operated and controlled by a computer control unit. Each unit's lifting and lowering operations occur simultaneously; the computer control unit's synchronous technology maintains the balance of the load. The hydraulics power units are embedded within each unit's lifting frame. Safe lifting heights are dependent on the expected side load.