Abstract: The present invention relates to a locking device (1) for a safety bar (8), comprising a fluid channel (10) having a magneto-rheological fluid (11), a movable locking element (40) and a magnet device (30), wherein the locking element (40) is coupled to the safety bar (8) and forces the fluid (11) through the fluid channel (10) when the safety bar (8) moves, wherein the fluid channel (10) has at least one channel portion (20), and wherein the magnet device (30) is arranged at least on opposing side walls (21) of the channel portion (20) in such a manner that the field lines (31) of the magnetic field of the magnet device (30) can pass through the channel portion (20). The present invention further relates to a passenger accommodation having a safety bar (8) and a locking device (1) and an amusement ride having a locking device (1) according to the invention.