Regarding the severe wear problem of the QU80 main rail in the gate slot of the ship lock working valve,an analysis of the specific wear condition is conducted.Studies are performed on several technical repair solutions,including complete replacement of the main rail,modification of the main wheel dimensions,surfacing welding on the rail tread,and plate welding onto the rail tread.A comprehensive cost-effectiveness analysis is conducted using a comparison method to evaluate various factors such as material selection,repair techniques,and operational performance.This analysis determined that the plate welding repair solution for the rail tread is the optimal choice.Specific process requirements for the plate welding repair solution are elaborated.The results show that by using wire-cut QU80 heavy rails to solve the problem of the unavailability of suitable materials on the market and implementing segmented plate welding to prevent the detachment or obstruction during the entire welding process,the severe wear repair of the QU80 main rail is handled quickly,effectively,and economically.This provides a valuable reference for addressing similar problems in other ship locks of the same type.Additionally,it is recommended that during ship lock maintenance,timely inspection of the wear condition of the QU80 main rail on working valves should be emphasized.Repair should be undertaken promptly when the wear exceeds 5 mm.