Shipyards throughout the nation are energetically endeavoring to rationalize and modernize the assembly stage of hull construction. As a result, due to the standardization of the production process with the enlargement of blocks and the wider application of the conveyor line system, it has become necessary to jumbolize the hardware and other manufacturing facilities. Under such circumstances, we saw the installation of this welding machine under the knowhow of the one-side automatic welding machine with ultra-multi electrodes as plate joining facility of the new assembling plant of the 600,000-ton tanker construction dock of KHI Sakaide Work. This welding machine has four sets of 3-electrode, submerged arc welding heads which can perform simultaneously parallel welding of thick plates of four welded joints in maximum by concentration control system. Along with the adoption of the practical crack prevention method for the end cracking of the welded parts, which was a bottle neck of one-side automatic welding technique, the introduction of this welding machine into the production line contributes greatly to the economy of labor-saving. This article deals with the outline of this welding machine and its operating conditions.
