Locking mechanism for bridge ship collision prevention system, fixed pulley and pulley system

The invention discloses a locking mechanism for a bridge ship collision prevention system, which is characterized in that the locking mechanism comprises a ratchet wheel which is coaxially and fixedly arranged with a first fixed pulley, a first mooring rope is wound on the first fixed pulley, and the locking mechanism further comprises a pendulum bob arranged below the ratchet wheel; the upper end of the pendulum bob is hung on a fulcrum fixed to the floating box in a swinging mode through a pendulum bob handle, the upper end of the pendulum bob handle is fixedly connected with a clamping plate in an inclined mode and abuts against the ratchet wheel, and when the impact force borne by the floating box exceeds the inertia effect of the pendulum bob, the pendulum bob swings to enable the clamping plate at the upper end to rotate and fall into ratchets of the ratchet wheel to be hung. The invention further discloses a fixed pulley and a pulley system which adopt the locking mechanism. The anti-collision device h