Based on practice and experience,this paper discusses some practicable repairing and correct checking of the axle deviation of lower bearing seat of rudder fixed by welding.

Following the mentioned procedure of determination of the interference,rudder bush loosen and rudder bearer bracket corrosion will be considerably avoided.

According to the weld cracked in the lower rudder bearing of a high speed ship,the authors analyzed the reasons causing the cracks in the welding of structures in the common mild,so as to explore the method to avoid the weld cracks.

Slewing frames consist of top slewing frame slewing bearing and low slewing frame.