Curved plate for railcar bodyshell, front car bodyshell, and method of manufacturing curved plate for railcar bodyshell

A method of manufacturing a curved plate for a front car of a railcar bodyshell,

• the method comprising:
• forming a plurality of reinforcing ribs to an upper surface of a metal material by machining the upper surface of the metal material, the plurality of reinforcing ribs projecting upward;
• forming machining reference surfaces on at least two of the plurality of reinforcing ribs, the machining reference surfaces being formed on same plane;
• forming on at least one of the plurality of reinforcing ribs a mounting reference surface perpendicular to one of a rail direction, a sleeper direction, and a vertical direction as a reference surface used when mounting the curved plate to the railcar;
• turning upside down the metal material, on which the plurality of reinforcing ribs are formed;
• placing the machining reference surfaces on a surface plate of a machining device;
• and
• forming, by the machining device, a plate main body by machining an upper surface of the metal material such that the metal material has the curved shape, machining reference surfaces of the upper surface of the metal material being placed on the surface plate.