Delta series

In-hook heave compensation


Seaqualize Balanced Heave Compensating (BHC) technology is now available in the first hook-based active heave compensation tool, for in-air heavy lifts: The Delta series.

Ranging from ~50 mT to eventually 2.000 mT and beyond, it opens up the road to floating installations of offshore wind turbine components or, complete turbines at once! The patented Seaqualize technology combines a very strong passive system, which renders the full load ‘weightless’. A very small active system (~5%) ensures extreme power efficiency to precisely position the load, and does not allow for accidental lift-offs or shock loads.

The Seaqualize Delta is the only in-air heave compensation that offers the reduced velocity and impacts that equipment manufacturers demand while protecting your crane. It turns every standard heavy lift crane into a high-performance AHC crane, only when the job requires. Seaqualize offers flexible lease solutions and operator support.

Why waste power, if you can balance any load?


Workability increase

Inline heave compensation reduces heave motions and set down-velocities by up to 95%. This allows shorter and better plannable installation campaigns:

  • Less waiting on weather days

  • Work longer into the heavy weather winter seasons

  • Faster and safer operations due to increased set-down control

The Seaqualize Delta can offer up to ~20-40% workability increase, especially in the demanding North-Sea.

Would like to analyse the potential workability increase for your operation in a particular location? Reach out to us, and we are more than willing to help using our in-house workability software.

Amount of time [%] at North Sea wind farm (Dogger Bank) when max. set-down speed < 5 cm/s. Workability analysis of 180m heavy lift vessel, crane positioned at stern, hook at 110m height, 30m radius, mass load 500 mT.

Amount of time [%] at North Sea wind farm (Dogger Bank) when max. set-down speed < 5 cm/s. Workability analysis of 180m heavy lift vessel, crane positioned at stern, hook at 110m height, 30m radius, mass load 500 mT.


Performance benefits of Seaqualize Delta

Increased control over in-air heavy load

  • Geostationary load: up to 95% motion reduction results in heavy loads that can be kept virtually motionless during in-air lifts while the crane vessel is subjected to sea states of Hs 2,5 to 3.0

  • Internal controls: Internal tool actuation controls for precise positioning and monitoring, fully parallel to standard hoist controls

increased control in load set-down phase

  • Slow set down: Set down velocities of 5 to 7 cm/s while in Hs 3.0 conditions

  • Accidental lift-off protection: 1,5m free stroke to prevent accidental lift-off under all circumstances

  • Snag load protection: the Delta tool absorbes any load shocks that may occur during the set-down phase, protecting the crane while increasing it’s load capacity

  • Increased load handling window: Guarantee longer period during which load is set-down but still ready for quick lift-off

Increase safety in heave compensated operations

  • No unintended actuation: Small actuation system (10% of full load) is incapable of provoking undesired load motions

  • Full passive load control: Passive system keeps the load fully balanced and under control for prolonged periods during any major system failure





We have done preliminary operational simulations with field experts from Heerema Marine Contractors, such as superintendents and crane drivers. Based on their feedback, we are improving feedback interfaces, tool controls and operational functionality 

We perform additional operational tests in-house to verify how our functionality holds up in various cases. For example: how to balance a turbine blade including the lifting tool that needs to stay behind?




2018 - Delta 0.05

Concept testing explaining the principle of the Delta heave compensation technology

partial shot2.jpg

2019 - Delta 2

Subsystem prototype: testing all final subsystems on scale


2019 - Delta 600

Start with engineering, production, certification and testing of the first full-scale demonstrator. Off-shore tests planned end of 2020