This wire rope tensioner cylinder series is the core actuator of the riser tensioning system on floating drilling platforms and drillships. It provides hydraulic thrust to the traveling sheave assembly, applying constant, controllable tension to the wire ropes connected to the riser. This action compensates for the vessel's heave motion caused by waves, tide, and current, preventing the riser from buckling under compression or being overstressed in tension. With an ultra-high thrust capability (up to 8,500 kN), materials meeting extreme cold-impact toughness, and a long-life multi-redundant sealing system, the cylinder delivers flawless zero-leakage holding and exceptional operational reliability in deepwater salt spray, heavy swell vibration, and continuous long-term loading — making it an indispensable component for safe floating drilling operations.