UNDERFRAME STRUCTURE OF RAILROAD VEHICLE

Provided is a underframe structure of a railcar capable of reducing a deformation amount of a cross beam supporting an underfloor equipement upon underfloor fire. The underframe structure of the railcar includes a underframe (1) having a pair of side sills (2) extending in a railcar longitudinal direction and a cross beam (3) arranged between the side sills (2) and extending in a railcar width direction, a structural floor (4) provided on an upper surface of the underframe (1), and an underfloor equipement (10) suspended down in a center part in the railcar width direction of the cross beam (3). The underframe structure further includes a passenger cabin floor (6) provided on an upper side of the structural floor (4), the passenger cabin floor forming a lower surface of a passenger cabin S, and floor receiving members (5) supporting the passenger cabin floor (6) and extending in the railcar longitudinal direction between the structural floor (4) and the passenger cabin floor (6), wherein among the floor receiving members (5), a floor receiving member (5a) provided in a substantially center part in the railcar width direction is attached to the structural floor (4) so as to bear at least a part of a load of the underfloor equipement (10).