Applies to the construction, installation, operation, inspection and maintenance of overhead and gantry stacker cranes with top running or under running bridge, multiple girder. The vertical mast for guiding the carriage is attached to the top running or under running trolley. These cranes are grouped because they all have the same features in vertically guiding the lifted load. Stacker cranes in this grouping include semi-gantry, cantilever gantry, and others having the same fundamental characteristics.