US Patent 7798471 Direct acting single sheave active/passive heave compensator

A heave compensation system provides a direct acting heave compensator that reduces stress and fatigue on a line, the system includes a single sheave system that compensates for heave as it carries a load line and moves along a curve profile of the heave compensator tangent to the point the load line comes off of a line handling system. The length of the line extending from the line handling system to the sheave remains substantially the same length during heave compensation operations, and the point where the line takes off from the line handling system is substantially the only point of changing stress on the line.