Welding of the external tank of the Space Shuttle

Welding processes and assembly techniques used in the fabrication of the external tank of the Space Shuttle are discussed. Each external tank consists of one liquid oxygen tank and one liquid hydrogen tank connected by an intertank skirt which is mechanically assembled; the fabrication of the external tank pressure vessel involves about 36,000 linear inches of weld required to join 138 pieces of 2219 aluminum. The discussion includes several innovations, such as building domes using the 1/4 panel assembly technique, which have been used in the fabrication of the tank.