4.5.2.1 Dimensions and construction materials
of masts and spars should be in accordance with the requirements or
recommendations of one of the Classification Societies referred to
in 4.3.1.1 or a recognised national or international standard.
4.5.2.2 The associated structure for masts and
spars (including fittings, decks and floors) should be constructed
to effectively carry and transmit the forces involved.