(a) With reference to fatigue of hull structures explain the influence of stress level and cyclical frequency on expected operating life. (6)

(b) Explain the influence of material defects on the safe operating life of forged components of stern fittings. (5)

(c) State the factors which influence the possibility of fatigue cracking of a bed-plate transverse girder and explain how the risk of such cracking can be minimized. (5)