Beckhoff technology drives Anemoi

Anemoi is a leader in rotor sail technology, a type of wind-assisted propulsion system that uses tall, rotating cylinders to generate forward thrust via the Magnus effect. These spinning sails use electric motors to generate thrust through aerodynamic forces, reducing the load on a ship's main engines and helping lower consumption. Anemoi continues to optimise the performance of its sails through ongoing R&D, with this project supported by a 1.4 million grant from Innovate UK.

To validate a new bearing and drive system design, essential components that support and rotate the sails, Anemoi commissioned a bespoke hydraulic test rig from Pressure Design. Instead of constructing full-scale sails, which are typically 35m high, the team built a compact, force-loading platform to simulate the effects of wind at sea.

"It was a clever way to test new component designs under realistic forces without the complexity of full-scale installation," explained Beth Ragdale, software product manager at Beckhoff UK.

Consolidating control

Beckhoff was brought in to provide a complete automation and monitoring solution for the rig. Central to the setup is a high-performance C6032 industrial PC, which consolidates control, data logging and vision capabilities.

The test rig features the same bearings and drive system as the real Rotor Sail, each fitted with a range of sensors to measure vibration, temperature and G-forces. These sensors capture data at 1,000 samples per second across 58 channels, which is logged and stored in a Microsoft SQL Server database using Beckhoff's TF3520 Analytics Storage Provider and TF3500 Analytics Logger. "Those tools gave us the ability to handle large volumes of high-frequency data without needing complex custom code," said Ragdale.

TwinCAT Vision software was used to integrate a thermal imaging camera that monitored tyre tread temperatures. Tyres are used to rotate the part of the rig representing the rotor sail, with hydraulic forces applied to mimic wind loads. The camera was a late addition to the project, added at the request of Anemoi to help assess tyre performance under different pressures.

"We were experimenting with different tyre pressures to optimise efficiency. The thermal camera gave us a live view of heat build-up, helping us identify where any energy could be lost," explained James Penty, director at Pressure Design.

Real-time visibility was a crucial part of the system. Beckhoff's Scope View software provided oscilloscope-style displays embedded in the HMI, allowing engineers to monitor parameters like vibration and thermal build-up. If any measurement exceeded a threshold, the system would trigger an automatic shutdown to prevent mechanical failure. "There was a strong emphasis on safety," said Ragdale. "If vibration was detected, the system could act instantly. Vibration is a red flag, as it only ever gets worse."

The system architecture was designed to be both compact and efficient. Beckhoff's EtherCAT P modules allowed the analogue-to-digital conversion to take place close to the sensors, reducing signal noise and simplifying the wiring. All data acquisition, control logic and visualisation tasks ran on a single industrial PC, avoiding the need for multiple systems. "We bundled everything - control, analytics, vision and HMI - into one IPC. That level of integration isn't typical," said David Grice, software applications engineer at Beckhoff UK.

Flexible benefits

From Penty's perspective, the key benefit of choosing Beckhoff was its flexibility. "It allowed us to encapsulate the entire hardware scope with one solution. The open architecture made it easier to integrate third-party components, including the customer-specified ABB drive and motor and certified marine sensors."

One unexpected challenge was aerodynamic drag. The test rig structure, unlike a real rotor sail, was open for easy access to internal components. However, this exposed steel frame created more drag than the real Rotor Sail, limiting the rig's top speed. "We added aerodynamic fairings to the structure to mimic the smooth shape of a real sail. That cut drag significantly and allowed us to reach full test speed," said Penty.

Other innovations included traction control logic for the tyre drive. The software is able to detect any loss of grip that might be experienced in wet conditions, and automatically reduces drive torque to prevent slip. According to Penty, these refinements help ensure the rotor sail system is practical and serviceable at sea. "Ships can go five years without returning to the shipyard for scheduled maintenance. In the unlikely event something fails, it has to be fixable by a marine engineer on board. That's why Anemoi have kept the design as simple and rugged as possible, while optimising efficiency for maximum savings in fuel consumption and emissions."

Automation and sustainability

Rotor sails are already helping shipowners reduce emissions, but automation is critical to accelerating adoption. With Beckhoff's technology stack, engineers at Anemoi can monitor complex dynamics and test under controlled, repeatable conditions. "It's all about validating and trusting the data," Ragdale added. "When you're running test cycles that last ten hours, you need to know your system can capture everything reliably."

For this project, testing is now complete and the first Rotor Sails using these components are in production, although the test rig will continue to provide useful data for future designs. Looking ahead, the team sees broader opportunities for automation to support sustainability goals in marine and renewable sectors.

According to Grice, "we're seeing increased demand for test benches and condition monitoring across wind, subsea and hybrid marine technologies. The ability to combine high-performance control with real-time insight is a game-changer." For Anemoi, this project marks a step in the evolution of rotor sail technology. For Beckhoff and Pressure Design, it offers a compelling example of how integrated automation can drive forward innovation in sustainable engineering.