To prevent the application of sudden braking of an iron wheel brake by detecting the quantity of stroke at the time of operating a brake pedal, and controlling the hydraulic force of a hydraulic brake unit in response to the detection value.

When a brake pedal 14 is operated during the traveling on a track, a stroke sensor 34 detects the quantity of stroke of the brake pedal 14 and outputs a current value. The current value detected by the stroke sensor 34 is input to a hydraulic control device 40 through an amplifier 38, and the set pressure of a proportional control valve 41 is controlled on the basis of the input value. Since the quantity of stroke is small at the initial time of brake operation, the braking force to be applied to an iron wheel brake 21 is small. But as the brake pedal is operated more, quantity of stroke is increased, and pressure inside of a control pipeline 42 is raised in proportion to the increased quantity of stroke. Hydraulic force of a hydraulic pipeline 22 is raised in proportion to the quantity of stroke, and the braking force to be applied to the iron wheel brake 21 is increased in proportion to the quantity of stroke.