Passenger reception means of a fairground ride, comprising a safety bar, wherein the safety bar can be moved manually or by corresponding actuating units from the open position into the closed position and vice versa, and furthermore comprises a locking system as a primary securing means, by which the safety bar is held in the closed position during the ride, wherein for the event of the actuation units or the primary securing means of the safety bar failing, a blocking device is provided as a secondary securing means, by which the safety bar is held in the closed position, wherein the blocking device comprises a fluid channel with a magnetorheological fluid, a movable blocking member, and a magnet device, wherein the blocking member is coupled to the safety bar and transmits a movement of the safety bar to the fluid in the fluid channel, wherein the fluid channel comprises at least one channel portion, and wherein the magnet device is arranged at least on opposing side walls of the channel portion in such a way that the field lines of the magnetic field of the magnet device can cross the channel portion, wherein the magnet device has a first state and a second state, wherein in the first state the magnetic field lines cross the channel portion, wherein in the second state the magnetic field lines are diverted or deflected from the channel portion or are attenuated in the channel portion, as a result of which the viscosity of the magnetorheological fluid remains substantially unchanged and the magnetorheological fluid can flow virtually undisturbed through the channel portion through the magnet device in a flow direction, as a result of which the safety bar is released in the second state and can be moved or pivoted, wherein the magnet device comprises at least one permanent magnet by which the permanently magnetic magnet device blocks the channel portion in the non-actuated first state, and the safety bar cannot be released, and wherein in the second state the safety bar is released, and wherein the fluid channel comprises at least one pressure compensation means. wherein for the event of the actuation units or the primary securing means of the safety bar failing, a blocking device is provided as a secondary securing means, by which the safety bar is held in the closed position, wherein the blocking device comprises a fluid channel with a magnetorheological fluid, a movable blocking member, and a magnet device, wherein the blocking member is coupled to the safety bar and transmits a movement of the safety bar to the fluid in the fluid channel, wherein the fluid channel comprises at least one channel portion, and wherein the magnet device is arranged at least on opposing side walls of the channel portion in such a way that the field lines of the magnetic field of the magnet device can cross the channel portion, wherein the magnet device has a first state and a second state, wherein in the first state the magnetic field lines cross the channel portion, wherein in the second state the magnetic field lines are diverted or deflected from the channel portion or are attenuated in the channel portion, as a result of which the viscosity of the magnetorheological fluid remains substantially unchanged and the magnetorheological fluid can flow virtually undisturbed through the channel portion through the magnet device in a flow direction, as a result of which the safety bar is released in the second state and can be moved or pivoted, wherein the magnet device comprises at least one permanent magnet by which the permanently magnetic magnet device blocks the channel portion in the non-actuated first state, and the safety bar cannot be released, and wherein in the second state the safety bar is released, and wherein the fluid channel comprises at least one pressure compensation means.