Guedes Soares and Garbatov (1996) developed a formulation for the reliability assessment of ship hull structures with respect to the fatigue failure of longitudinal members, in which the crack growth is modelled for the case of existence of multiple cracks. The same authors studied similar topic, but extended the scope of the developed model by considering corrosion and also combined loading that includes the stresses from vertical and horizontal wave-induced bending moment and external sea water-induced pressure and cargo loading (Guedes Soares and Garbatov, 1998). Other studies on the fatigue assessment of ship structures are presented by Garbatov et al. (2004) for converted FPSO, Akpan et al. (2002) for tankers, Paik et al. (2003) for bulk carriers, Chakarov et al. (2008) accounting for imperfections and Garbatov et al. (2002) accounting for nonlinear corrosion.