PURPOSE: To enable heavy weight to be used by lifting up a weight through a moving pulley attached to a tower by means of a wire rope for lifting up the weight of a crane.

CONSTITUTION: A wire rope 5 for lifting up a weight is extended downwards from the fixed pulley 10 of a crane top sheave 9 and engaged with a moving pulley 17 and a fixed pulley 16, and its free end is connected to a tower 3. The pulley 17 is attached with a hook 18 for hanging down of the weight and a separator 19 for the weight. A wire rope 6 for lifting a tower is engaged with the pulley 10 and a moving pulley 11, and its free end is connected to the tip of a crane boom 8. A hook 13 for hanging down of the tower 3 is attached to the pulley 11. When the ground is consolidated, a weight 2 is lifted up and separated by the separated 19 to allow it to drop naturally.