OE Systems AB

From concept to a subsea hydraulic power module

At the heart of OE Systems’ WaveMove wave energy converter is a compact subsea module containing the hydraulic, electrical and control equipment required to manage movement and convert wave energy into usable power. HydTec transformed the developing concept into manufactured and workshop-tested hardware through detailed engineering, 3D packaging, custom fabrication, system integration and commissioning.

Challenge:

The customer needed to integrate complex hydraulic, mechanical, electrical and control equipment within a compact subsea module while preserving function, accessibility, sealing integrity and a practical route from prototype testing to full-scale assembly.

Delivery

HydTec delivered detailed engineering, component and material coordination, custom parts, hydraulic and mechanical assembly, pipe and hose installation, workshop commissioning, FAT support, modifications and troubleshooting for the pilot rig and subsequent subsea module.

Results

HydTec converted evolving requirements and supplier data into assembled, workshop-tested hardware. Key hydraulic functions were verified during pilot testing, while later FAT and commissioning exposed installation issues that were corrected before the subsea module left HydTec.

GO TO RESULTS

Initiation

Two hydtec employees and two OE Systems employees stand beside a large blue and yellow industrial hydraulic machine in a workshop, with one holding a laptop.

Initial assessment

OE Systems developed the WaveMove concept and worked closely with Parker on the hydraulic principles, core component architecture and specialist product input. HydTec joined as the system realisation and integration partner, responsible for turning the evolving concept into manufacturable and testable hardware within a demanding subsea envelope.

The physical power-conversion unit is technically known as the power take-off, or PTO, module. HydTec reviewed its operating modes, developed hydraulic functional proposals and established a staged route from proof of concept to detailed design, procurement, manufacturing, assembly and workshop verification.

Communication

The project was carried out through close cooperation between OE Systems, Parker and HydTec. HydTec became the practical coordination point between customer requirements, Parker’s hydraulic and component input, manufacturing constraints and the physical build.

Technical workshops, design reviews and ongoing communication were used to manage P&ID changes, BOM updates, component availability, interfaces and workshop findings. HydTec produced hydraulic concepts, 3D and manufacturing data, material schedules and test-related documentation, with changes fed continuously into the build.

A woman in a black blazer and t-shirt stands next to a large industrial boiler or heat pump system, gesturing toward the machinery. The t-shirt features the text 'OE SYSTEMS'.

Process

Three blue electrical inverter/charger units assembled together, part of the electrical control system in HydTec's subsea power module build.

Design & Engineering

HydTec began by translating operating scenarios into hydraulic pilot and full-scale functional concepts covering energy extraction, cylinder return, safety mode, pressure monitoring and system protection. Customer geometry and supplier models were then incorporated into a HydTec working assembly to determine how the complete hydraulic, electrical and control installation could be packaged and serviced inside the restricted subsea module.

The detailed work extended across hydraulic, mechanical and electrical interfaces. HydTec evaluated tanks, accumulators, motors, valves, sensors, cooling, pipe and hose routes, penetrations, lifting and access requirements. Tank volume and oil viscosity were checked, while component positions and mounting solutions were repeatedly reviewed against the physical assembly.

Where standard parts or supplied geometry did not fit, HydTec redesigned brackets, plates, adapters, blocks, guards and supporting structures. This iterative engineering work allowed conflicts and serviceability problems to be resolved before offshore installation rather than transferred to the deployment site.

Manufacturing

HydTec carried the design into a complete workshop build. The work included cutting, welding and modifying steel and sheet-metal parts; manufacturing brackets, sensor guards, adapters and distribution blocks; modifying and pressure-testing tanks; and preparing components for coating.

The team installed valves, accumulators, hydraulic motors, sensors, HPU equipment, cooling components, piping and hoses, while also accommodating electrical equipment and connection structures within the common subsea module.

Assembly findings were treated as engineering inputs rather than simple deviations. Mounting plates were redesigned when interfaces collided, pilot circuits were modified, pipe and hose routes were adapted, and components were dismantled and rebuilt when orientation or supplied-item errors were discovered.

HydTec then performed start-up, leak detection, functional checks, and FAT-related troubleshooting. The result was not merely a collection of supplied components, but an integrated and workshop-verified subsea hydraulic power module prepared for the customer’s next installation stage.

Results

Large-scale OE Systems WaveMove wave energy converter components, including hull and buoy structures, in a warehouse before installation.

Installation & commissioning

The first-stage hydraulic functions were commissioned and tested at HydTec with customer participation. Initial testing confirmed the main pressure and flow relationships, controllable cylinder loading, safety-mode behaviour and main-pump capacity.

The subsequent subsea hydraulic power module was also started, checked and modified in HydTec’s workshop before being transferred to the customer.

Follow up & support

HydTec remained involved throughout the successive test and build stages, responding to design changes, component substitutions, workshop findings and FAT issues. Continued technical support has been available for parts and system-related questions.

From concept to a subsea hydraulic power module