To reduce the time and cost and to prevent the danger of scaffold workers of a cargo storage section including the assembly and removal of erect members and plates by providing an automated friction blasting device horizontally movably along four faces of a safety rail respectively.

A blast machine 70 is arranged to face the face 24 of a storage section and sprays friction sand such as steel shots from an impeller or an injection machine 72 through the opening section of a housing facing outward. The blast machine 70 is pushed or pulled along a rail 68 by a mechanism 74 such as a motor driven gear meshed with a rail face or a motor driven rubber wheel friction-coupled with the rail 68. Consumed steel shots are dropped on the floor surface of the housing of the spray machine 72 together with refuse and are collected by a return line, then they are sent to a base section 36 or a reproduction station provided on the outside of the storage section.