Inline active heave compensator

Inline active heave compensator (IAHC)

Safelink’s inline active heave compensator (IAHC) provides position and velocity compensation for all types of structures independent of geometry and mass, both subsea and in air.

The IAHC is built around a passive principle with a gas balanced piston. A passive system does not provide any motion reduction for lifts performed in air as there is no added resistance to changes in the object’s velocity, e.g. added mass and drag area which are effects seen when the payload is submerged.

The IAHC with the active element can compensate any type of load in air by balancing the forces experienced by the payload. The IAHC can run both in passive and active mode, creating new possibilities for usage, that cannot be matched by traditional AHC systems.

Safelink´s IAHC enables use of low-cost cranes and winches to be used for complicated lifting operations. The IAHC also serves as a good backup for AHC cranes, and being a mobile unit, can easily be deployed to where it is needed.

Having a mobile system provides a high degree of flexibility in addition to a cost-effective solution. The system can be scaled to provide heave compensation for heavy loads. Motion can be synchronised between two moving objects enabling floating-to-floating operations. All of the features from passive compensators and shock absorbers are available with the IAHC.

Key features

  • Motion and velocity reduction >95%
  • High SWL capacity
    • Designs up to 2400 t SWL
  • High speed
    • 2.4 m/s system under construction
  • Stroke length up to 12 m
  • Weight of system 5-10% of SWL
    • Higher SWL yields lower percentage self weight
  • Regenerative during operation
  • PHC mode as fail-safe
  • Plug and play – everything integrated into the unit
  • Certification according to DNV

Active heave compensator for offshore wind (AHC-W)

The new hook-based active heave compensator for offshore wind (AHC-W) was developed exclusively for the offshore wind installation market. Its cost and weight are significantly reduced compared to the AHC introduced by Safelink back in 2017, which was developed for both topside and subsea use down to 3000 metres.

The weight and cost reduction will make this the most cost-effective and flexible AHC for offshore wind installation.

The core capabilities of the AHC-W are:

  • Operational weather window extension of more than 70% in several case studies
  • Floating to floating, floating to fixed and fixed to floating installations
  • Keeping DAF under control