Frequensea Decommissioning Tool completes Factory Acceptance Testing and arrives at Deltares 

Frequensea's decommissioning tool with integrated vibration motors suspended above the Deltares tes basin following successful factory acceptance testing, ready for the next phase of validation

The Frequensea Decommissioning Tool has reached another important milestone in its development. The integrated vibration motor assembly (vibration module) successfully completed factory acceptance testing at steel construction specialist J. van Belzen, where functional and watertightness tests confirmed its performance and integrity. 

The vibration module has now been delivered to Deltares, where the next phase of the qualification programme is about to begin. 

At Deltares, the vibration module will undergo a series of sweep tests under controlled laboratory conditions. During these tests, the assembly will be placed under water beneath a layer of sand in a dedicated test basin, replicating subsea buried conditions. By gradually varying the operating frequency of the vibration motors, the test team will determine the optimum frequency at which soil liquefaction occurs. These results will form the basis for the entire testing programme at Deltares this summer. 

Once qualified, the Frequensea Decommissioning Tool will utilise its patented vibration-induced fluidization technology to provide the offshore industry with an efficient and environmentally responsible solution for the removal of redundant subsea cables and pipelines. 

By minimising disturbance to the surrounding seabed, the technology supports the growing need for sustainable offshore decommissioning. 

Frequensea Decommissioning Tool Reaches Key Fabrication Milestone

Vibration motors undergoing initial commissioning tests, powered by variable frequency drives (VFDs) prior to installation in the Frequensea Decommissioning Tool

The development of the Frequensea Decommissioning Tool is advancing rapidly, with fabrication, assembly and integration activities now in full swing.

Major structural components and subsystems are currently being assembled and integrated at Van Belzen, a specialist in steel construction. The Drive and Control systems are being prepared by EPMC Europe. This week marked an important milestone as the vibrating motors were successfully powered by the VFD for the first time, ready for installation into their steel housing.

Over the coming weeks, the project team will carry out pre-run and acceptance testing to verify functionality, subsystem integration and watertightness.

The Frequensea Decommissioning Tool was designed by sister company Enersea, leveraging its extensive offshore engineering and subsea expertise. Frequensea B.V. is responsible for the development, qualification and future commercialisation of the technology.

Designed for the environmentally responsible removal of subsea cables, umbilicals and pipelines, the Frequensea Decommissioning Tool utilises patented vibration-induced fluidisation technology to efficiently extract buried assets while minimising disturbance to the surrounding seabed and marine environment.

Further updates will follow soon as the project progresses through testing and development.

Frequensea would like to acknowledge the valuable support of its early development partners DEME and SCA as well as the Topsector Energie / Energy Innovation NL subsidy provided by Netherlands Enterprise Agency (RVO).

Key Fabrication Milestone for the Frequensea Decommissioning Tool; the vibration motors have been successfully powered up and tested for the first time.

Frequensea winner Offshore Energy Innovation Award!

Frequensea winner Offshore Energy Innovation Award

Frequensea was announced as the winner of the Innovation Award during the second day (26 November) of the Offshore Energy Exhibition & Conference (OEEC25).

In his innovation pitch, Dieter Korndorffer, Managing Director and co-founder of Frequensea, highlighted the growing need for environmentally responsible cable decommissioning as the first offshore wind farms approach the end of their operational lifecycles.

Frequensea’s decommissioning tool, currently under development, is designed to enable this process to be carried out safely, efficiently, and in a more cost-effective manner.

Speaking on The Stage in front of the audience, Dieter expressed his enthusiasm and appreciation for the recognition, stating that this acknowledgment reinforces Frequensea’s position as a potential game changer in offshore decommissioning.

Busy Frequensea stand at OEEC25

Frequensea stand at Offshore Energy 25

The Offshore Energy Exhibition & Conference 2025 (OEEC25) at the RAI Amsterdam is in full swing. The Frequensea stand (no. 2.103) in the Innovators Area has been well attended by potential clients interested in the patented Frequensea technology.

On 25 November, the first day of the exhibition, Dieter Korndorffer, Managing Director of Frequensea, delivered an Innovation Pitch at the Square podium, which was received enthusiastically by both the audience and the moderator.

Today, from 14:00 to 15:00, Dieter will represent Frequensea as one of seven finalists by presenting the Frequensea decommissioning tool at the Innovation Award Show on The Stage in Hall 1.

With the jury questioning the finalists, this session promises to be one of the most interesting parts of the programme.

Frequensea nominated for Best Innovation of 2025

Frequensea nominated for Best Innovation of 2025

Frequensea is proud to announce its selection as one of the seven finalists competing for the Best Innovation of 2025 award at the Offshore Energy Exhibition & Conference (OEEC).

Frequensea will present its subsea decommissioning tool during the Offshore Energy Innovation Show at podium The Stage from 14:00 to 15:00 on 26 November, the second day of OEEC.

Managing Director of Frequensea, Dieter Korndorffer, will pitch the decommissioning technology that combines controlled vibration with fluidisation to loosen and remove subsea cables and pipelines safely, efficiently and cost effective while reducing seabed disturbance.

“We are honoured to be recognised among such strong and forward-thinking innovations,” said Korndorffer. “This nomination highlights the potential impact of our technology on the offshore energy sector.”

The technology pitches of the seven finalists will be judged by an expert jury. The winner will be announced after all contestants have presented their innovation and the judges have completed their deliberation.

Frequensea awarded EKOO grant for efficient decommissioning of subsea infra

Frequensea concept for cost efficient removal of subsea infrastructure

Frequensea and Deltares have been awarded a grant under the
EKOO – TSE: Electricity 2025 programme by the Netherlands Enterprise Agency (RVO). The subsidy will be used to further develop the novel patented Frequensea concept into a working subsea cable decommissioning tool by designing, testing, and validating it in practice.

Frequensea is a pioneer in subsea infrastructure removal, developing an innovative vibration-assisted method for the safe and efficient decommissioning of cables and pipelines. Deltares complements this with advanced research facilities and expertise in evaluating the environmental effects of subsea operations, ensuring the concept is both technically effective and ecologically sound.

The Frequensea concept uses controlled vibrations to reduce soil resistance. This approach makes it possible to remove buried infrastructure with smaller vessels, lower energy demand, and less disturbance to the seabed, while preserving materials for potential reuse.

The joint proposal submitted by Frequensea and Deltares ranked first among 12 submissions in the EKOO call, thanks to its innovation, sustainability benefits, and market potential.

“This subsidy is a major milestone for us” said Frequensea Managing Director, Dieter Korndorffer. “It enables us to prove our concept and bring the offshore industry closer to environmentally friendly and cost-efficient decommissioning.”

Mario Martinell, Expert advisor at Deltares added: “At Deltares, we see sustainable decommissioning as key part of the energy transition. Through research and innovation, we aim to provide the knowledge needed to support effective removal of offshore infrastructure.”

Over the next two years, the project will deliver a validated concept, positioning Frequensea and Deltares for further development toward full-scale deployment and contributing to a cleaner offshore energy landscape.