Riding weight
In shipping, a riding weight is a weight that is slidably attached to an anchor chain or anchor line. It is fastened with a shackle or a special riding weight roller , for example . For precise positioning, a rope can be attached to the same attachment , with which the weight can be pulled up or down along the chain.
The riding weight changes the direction of the tensile forces acting on both ends of the chain or line. At the anchor itself, you want to ensure that the line runs at as flat an angle as possible to the anchor base so that the anchor does not break out under load (is torn from the anchor base). At the anchored ship you want to reach the steepest possible angle of the line in order to keep the circle of swivel small. These optimization goals contradict each other if no riding weight is used.
The riding weight causes a kink in the anchor chain at its attachment point, which causes the angle between the anchor and the kink to become flatter and the angle between the kink and the ship to be steeper than would be the case with the same distance between ship and anchor with the line not kinked. Conversely, the horizontal distance between anchor and ship necessary to achieve a shallow angle at the anchor can be kept smaller, which means that less chain or line is required.
The course of a freely hanging chain or leash lies approximately on a catenoid (chain line) running through the two ends . As a result, even without a riding weight, the tangent angle at the attachment point on the ship's side is steeper than the tangent angle at the anchor-side attachment point, which is close to the lowest point of the catenoids.
The angles and distances considered are subject to fluctuations, as currents, wind, waves and changes in the water level change the tensile forces and the position of the ship. If the distance between the ship and the anchor increases, the riding weight is increased by tightening the chain or line. The overall system of leash and riding weight can cushion abrupt increases in tensile force . This reduces the force changes directly on the armature and prevents the armature from tearing loose.