Stacker crane and method for operating same

A method for operating a stacker crane that includes a lower carriage including a lower drive wheel in contact with a lower rail, a lower travel motor that drives the lower drive wheel, a support located apart from the lower drive wheel along a length direction of the lower rail, an upper carriage including an upper drive wheel in contact with an upper rail, an upper travel motor that drives the upper drive wheel, and a mast fixed to the lower carriage, standing upward from the lower carriage, connected to the upper carriage, and having a transfer device attached movably up and down, the lower carriage is provided with a displacement mechanism that raises and lowers the support between a grounded position supported by the lower rail and a retracted position lifted upward off the lower rail, the method comprising:

• lowering the support to the grounded position supported by the lower rail when the stacker crane is installed between the lower rail and the upper rail and when the stacker crane is stopped to perform maintenance;
• and
• raising the support to the retracted position lifted off the lower rail when operating the stacker crane.