Adaptive passive heave compensator in action

Adaptive passive heave compensation

Your complete solution for subsea installations. Our advanced heave compensators provide unbeatable performance throughout the entire operation from topside to subsea.

In general

We have taken the limitations of standard passive heave compensation and developed state-of-the art technology for marine operations.

Our newest PHC units have an unbeatable interactive control system. We have transferred our knowledge about how PHC should work at different stages of marine operations and given the unit the capability to adapt to various environments. The units are just as robust and easy to install as standard PHC units. Thet offer excellent performance for both topside and subsea applications – targeting all dynamic challenges with one single unit.


Selected features:

  • Excellent performance for both topside and subsea applications
  • Capability to target multiple application areas during the same operation
  • Movement and velocity data can be retrieved for evaluation of the operation
  • User-friendly setup with handheld tablet

Topside and subsea mode

Our advanced mechanical design and control system enables the unit to be preset with several combinations of gas spring and hydraulic damping.

Settings can be changed automatically or manually by tablet (topside) or ROV (subsea).

Shock absorption

Safe deployment through the splash zone:

  • Remove the risk of slack slings and/or snap loads
  • Reduce dynamic load variations

Overload protection with option for subsea adjustment

  • Extend to compensate if forces exceed estimated values
  • Overload protection in case the active heave compensation system fails
  • Read actual registered load during operation (ROV panel)
  • Adjust settings subsea during the operation to compensate for inaccuracies

Subsea resonance avoidance

Resonance occurs when the natural period of the lifting system is equal to the surrounding wave period. It is difficult to estimate the exact water depth at which these periods will converge

  • Our adaptive PHC solutions will change the natural period of the lifting system to completely avoid resonance, even in ultra-deep water

Landing speed reduction

Operational requirements when installing various subsea structures normally include a maximum value for landing velocity. It is essential that these requirements are met. Safelink adaptive PHC solutions will increase the weather window and reduce down time of subsea installations.

  • Excellent performance for landing speed reduction.
  • Reduce landing speed for all wave periods – even for long wave periods.
  • Reduce landing speed for all structures – even for structures with little drag and added mass properties.

Subsea retrieval with option for subsea adjustment

Subsea retrieval (e.g suction pile retrieval)

  • Extend and retract to compensate for the dynamic load variations caused by topside movement
  • Extend to compensate if pull-out forces exceed estimated values
  • Controlled retraction when the subsea structure is released from the seabed

Pull-out forces can be difficult to estimate and we often see that these operations require overload protection to deal with deviations. The inclusion of our adaptive PHC solution will enable the option to:

  • Read actual registered load during pull-out (ROV panel)
  • Adjust settings subsea during the operation to compensate for inaccuracies

Recorded data for post-processing

Onboard computer data can be retrieved after lift

  • Verify that operation was conducted in line with end-client’s requirements
  • Measurements of forces and payload motions
  • Can be used to verify installation analysis
    Computer log can be synchronised with vessel MRU

Did we mention that you only need one Safelink unit to utilise all available functionality and solve both the topside and subsea challenges of your operation?