Method for monitoring a lifting system

A method of monitoring a lifting system for lifting a load, said lifting system having at least two lifting devices, each of which comprises a basic framework, a lifting unit, a load-bearing device, and a supply line, by means of which supply line each lifting device is connected to the other lifting device, and during at least one of lifting and lowering of the load, a fractional amount of the load to be elevated or lowered acting on the load-bearing device is sensed by a pressure sensor of the lifting unit and evaluated in a control unit, wherein

• in order to initially lift a load, a lifting movement of each load-bearing device is initiated in a starting phase,
• the lifting devices are driven individually in the starting phase,
• the load-bearing device of each lifting device is raised until a preset minimum load is sensed by the pressure sensor, as the load-bearing device acts on the load which is to be lifted, and the respective load-bearing device is brought to a standstill when the minimum load is reached,
• in a load-detection phase of a lifting operation, this phase following the starting phase, lifting movements of the load-bearing devices are continued jointly and the load-bearing devices of the lifting devices are raised a preselectable displacement distance, and
• once the preselected displacement distance has been covered, load interrogation is carried out for each lifting device, and a load determined for each lifting device is stored in each lifting device as a reference value for further lifting movements of the lifting operation.