4.2.1 In general, hull strength, scantlings and arrangements for surface type
units are to comply with the relevant requirements of the Rules for Ships as
applicable to the service of the unit. For drilling units, the local design heads to
be used for the derivation of scantlings for walkways and access areas, work areas
and storage areas are not to be less than as shown in Table 6.2.1 Design heads and permissible
deck loadings (SI units) in Pt 4, Ch 6 Local Strength.
4.2.3
Drilling well/Moonpool. The hull structure in way of the drilling
well/moonpool is to be suitably strengthened so as to ensure continuity of the
required longitudinal strength.
4.2.4
Structural analysis. For surface type units, the strength of primary
structures of hull compartments and of deck supporting structures, including
longitudinal and transverse bulkheads, is to be assessed in accordance with relevant
LR ShipRight SDA Procedures.
4.2.5
Fatigue design. Fatigue damage due to cyclic loading is to be considered. The
nature and extent of the fatigue analysis will depend on the mode and area of
operation. For details of the fatigue required analyses, see
Pt 4, Ch 5, 5 Fatigue design.
4.2.6 The scantlings and arrangements of units with a limited number of tanks
for bulk storage of flammable liquids having a flash point not exceeding 60°C
(closed-cup test) will be specially considered. Double hull construction in bulk oil
tank storage regions will normally be required, see also
Pt 3, Ch 3 Production and Storage Units.