Strange kites from space technology

Wind-assisted propulsion has become a routine topic of many commercial and technical discussions in shipping. However, the question remains whether we are asking the right questions, and finding the right solutions.

The usual pattern is to install a system on a selected vessel, monitor several voyages, and collect fuel and performance data to support investment decisions and regulatory planning.

Data collection

For the technical teams involved, these trials are rarely taken lightly. Superintendents and fleet managers collect daily data on performance, weather routes, power consumption and crew feedback. They try to understand not only whether a system works, but also under what conditions it works and how it affects the ship’s compliance profile.
The difficulty they keep coming back to is variability.
Wind close to the sea surface is affected by waves, temperature layers, ship speed and route. A change in engine speed, an anomaly in the weather or a different load can alter the airflow around the ship. As a result, two vessels using the same equipment on similar routes may end up reporting very different results.
This makes it difficult to draw firm conclusions from short trial periods, even when data are carefully collected and reconciled with CII or FuelEU reports.

Aerospace Engineering

Aldo Cattano, founder of Windtracx, has a background in aerospace engineering, including aircraft certification and autonomous flight systems. When he started looking into maritime wind-assisted propulsion, he focused less on the sail area and more on how much control the system had over the air in which it operated.
Many existing technologies work at different altitudes, but they all remain subject to atmospheric conditions that change from minute to minute. They can only respond to what the wind provides.

Active wing

Windtracx takes a different approach. The system launches a kind of box kite with rigid wings from the ship and lets it fly a few hundred metres above the surface. At that altitude, the airflow is generally calmer and more stable. More importantly, the wing is actively controlled.
By flying controlled patterns, the kite generates its own apparent wind. The faster it moves through the air, the more aerodynamic force it can create. From an engineering point of view, this shifts the system from waiting for usable wind to producing lift through motion.

More consistent performance

For technical managers evaluating wind support in the context of CII scores, charter party clauses and FuelEU compliance, this distinction is important. Passive systems respond to every wind they encounter. An actively flown wing introduces a degree of control that allows for more consistent performance adjustment and comparison.
There is also a secondary effect once the wing is airborne. From a few hundred metres above the ship, the aircraft can observe a large area around the ship, including wind patterns, approaching weather and nearby traffic. In this sense, it becomes both a propulsion device and an airborne sensor.

Extensive trials

Whether this type of system can meet the reliability, safety and class requirements of commercial shipping will only become clear through extensive trials and operational experience. What is already clear is that wind-assisted propulsion is moving beyond sails and rotors to systems that lean heavily on aerospace technology. For owners and technical teams developing decarbonisation strategies within the IMO and EU framework, this presents both opportunities and complexity. The systems being tested today may not look like those that will be widely deployed later in this decade.

Source: Mariner news.
Image: Windtracx.

Windassist sponsor