PURPOSE: To shorten the drop distance of a content as far as possible and to prevent the generation of a gouge easy to cause at charging time by tilting a barrel tank corresponding to the tilting of a bucket.

CONSTITUTION: The tilting of a barrel tank 7d is detected as the azimuth of the rotating shaft of the barrel tank 7d from a reference position. Also the tilting of a bucket 35g is detected as the length of the chain to move the bucket 35g corresponding to the curvature of a guide rail. The charging distance is thus shortened inevitably because of one part of the bucket 35g being faced to the barrel tank 7d inside and the content being abutted to the side wall of the barrel tank 7d by corresponding to the tilting of the bucket 35g and that of the barrel tank 7d and the impact at the charging time can be intensely reduced.