In the previous paper, the elastic behaviour of the simple superstructure constructed with horizontally and vertically corrugated plates was investigated. But the horizontally corrugated wall, in general, will have to be stiffened by transverse frames or stiffeners, to maintain sufficient transverse stiffness of the cross section of superstructure against the lateral loads. When the stiffeners are rigidly attached to the every corrugation and the corrugations are restrained from distortion of their cross sections, the merits of the corrugated plates will vanish and the large longitudinal stresses may be transmitted from hull girder. To find out the construction of the corrugated side wall of the superstructure which has sufficient transverse stiffness and does not transmit the large longitudinal stresses from main hull to the bridge deck, the effects of the stiffener attached to the corrugated wall on the tensile and bending rigidity of the superstructure were researched.