Selected Welding Techniques

Marshall Space Flight Center specifications for welding large, single tank boosters are rather stringent, calling for no undercutting, no cracking, complete fusion, and a relatively small amount of porosity. In order to maintain design tolerances it is necessary to rely on electronic positioning controls to keep the torch on the joint to be welded. When tests of certain available systems proved conclusively that they were not adequate, Marshall personnel set out on their own development programs. The problems were many but the results were gratifying. It is believed that proximity and seam tracking controls adequate for most anticipated applications are now on hand.