Abstract: A portable electric power source for movable welding equipment used for constructing storage tanks and the like comprises a platform; an engine mounted on the platform; an AC electric generator mounted on the platform and driven by the engine; a welding machine, mounted on the platform, including electric current inverter and transformer means by which AC electric current from the generator is converted to DC welding current; and current transmission means for conveying the welding current from the welding machine to the welding head of the associated welding equipment. The welding equipment and the power source are mounted on carriages which are coupled together so as to move in unison as the welding operation progresses.

Abstract: A method of installing a boom on the top of a high vertical tower comprising vertically positioning a first tower section and securing the tower section to a base; installing a plurality of additional tower sections in consecutive order on top of the first tower section and securing the adjoining sections together until a tower is erected having a desired height; a boom having a base section, at least one extendable section and a load lifting end; releasably attaching the boom in vertical position to and along side the tower as it is erected with the boom load lifting end at the bottom; jumping the boom vertically upwardly by alternately extending and retracting various boom sections as the tower sections are installed; positioning the boom base end adjacent the boom turret, tilting the boom turret into close contact with the boom base end and joining the turret to the boom base end by a horizontal boom footpin; releasing the boom lifting end from the tower; tilting the turret into contact with the adapter up