CONSTRUCTION METHOD FOR HEIGHTENING STEEL TOWER AND TEMPORARY METALLIC ARM USED IN THE CONSTRUCTION METHOD

PROBLEM TO BE SOLVED: To provide a construction method for heightening a steel tower for shortening a period of power stoppage to suppress obstacles in electric power supply during heightening construction work to the minimum and returning from the power stoppage quickly in a short time from the viewpoint of stable electric power supply, and to provide a temporary metallic arm used in this construction method. SOLUTION: In this construction method, supply of electric power to right and left circuits 16R, 16L of an existing steel tower 1 is alternately stopped, members 50, 51R, 51L, 52R, 52L being the temporary metallic arms 49 are attached to an inner side of the existing steel tower body provided with upper-phase wires 13R, 13L, ground electric wires 9R, 9L and the upper- phase wires 13R, 13L are moved to the temporary metallic arms, a top part of the existing steel tower body 1 supporting existing metallic arms and existing metallic arms 5R, 5L, 6R, 6L are cut and removed, a new tower body 17 is assembled on the top part of the existing steel tower body being cut and removed, supply of electric power to the right and left circuits is alternately stopped, new metallic arms 18R, 18L, 19R, 19L are attached to the new tower body, the ground electric wires and the upper-phase wires are moved to the new metallic arms, and the temporary metallic arms are removed. COPYRIGHT: (C)2011,JPO&INPIT