DNV GL MATERIALS AND WELDING II-3-3 PDF

These rules apply to all welding work carried out on the ship's hull, including the superstructure and deckhouses, its internal and external structures, and equipment components forming part of the ship's structure, e.g. hatch covers, masts, king posts or crane substructures welded to the ship's hull. See also Chapter 1, Section 1, A.1. and A.2.

They also apply in analogous manner to cargo tanks which are not an integral part of the ship's hull and are not pressure vessels within the meaning of Section 3 (e.g. prismatic type A tanks, according to the Rules for Construction I, Part 1, Chapter 6).