The outer hull, which accommodates the main ballast tanks and external fuel tanks, and fines off the form of the vessel forward and aft, is built outside the pressure hull.
Isiqu sangaphandle, eligcina itanki elikhulu elinzimu, numatanki ezibaso ungephundle, nezinye izinte ezilulilo lwesikhitshona lwangophombili notwangemva, zukhiwe ngophandle koxinzelelo lwesiqu.