Railway braking system and railway vehicle provided with such a system

A railway braking system for a railway vehicle, including a brake cylinder (2) configured to act on braking members (18) of the railway vehicle, an actuation device (14) configured to lock the brake cylinder in a braking position and an unlocking device (50) configured to unlock the actuation device by actuation of a control mechanism (40), wherein the control mechanism includes a control member (63) movable in translation according to a first direction and housed in a casing (33) of the unlocking device connected to the brake cylinder, the control member being configured to cooperate with the actuation device, and a blocking member (64, 77) mounted movable in translation according to a second direction perpendicular to the first direction of movement of the control member and housed in the casing of the unlocking device, the control mechanism being configured so that, when the actuation device is in a locking position of the brake cylinder and the control member is urged and moved towards a maintenance position in which it is configured to make the actuation device pass into an unlocking position, the blocking member is urged and moved in a position in which it blocks the control member in position.