Motion compensator

[[Category:]]A motion compensator is a device that decreases the negative impact of the relative movement of two objects on the connection between these objects. In general a motion compensator is built in the connection between a floating object and the connection to the seabottom. The motion compensator does not compensate the motion, but tries to eliminate the negative influence of the movement (difference).

The simplest motion compensator is the anchor chain of a floating object. The shape of the chain makes that in case of moving of the ship, the forces on the anchor and the ancher chain remain acceptable. In general however a motion compensator is a "spring". For large forces this spring is in general a hydro pneumatic spring: a plunger cylinder connected to a gas volume.