PURPOSE: To prevent a structure built on blocks in the dry dock from tumbling by a method wherein the structure is loaded with ballast for balancing and is provided with a buoyancy before the heavy articles is loaded on the structure.

CONSTITUTION: The structure 3 is fabricated on the blocks placed on the bottom 1 of the dry dock, and the heavy article 4 is loaded on the structure 3. The structure 3 is loaded with ballast to satisfy the optimum condition, and sea water is introduced into the dock to provide the buoyancy for the structure. Numeral 6 represents a dry dock gate.