VESSEL REVIEW | Willelectro – Demonstrator USV built for freight transport in port waters

UK-based RAD Propulsion recently introduced a new unmanned surface vehicle (USV) that served as a proof-of-concept demonstrator of low-emission maritime transport in ports.

In collaboration with local logistics company and vessel operator Williams Shipping, RAD Propulsion designed, developed, and operated Willelectro, a compact USV that the partners called a “micro freight delivery vessel.” The objective was to show that freight can be transported effectively over short distances with less manpower and without relying on traditional marine propulsion systems.

Lightweight construction for ease of navigation and improved performance

The USV is of composite construction to ensure a displacement of under two tonnes, thus making it lighter and more manoeuvrable and therefore more capable of navigating autonomously in busy port waters.

Details on its exact length have not been disclosed, though the craft is small enough to sail through narrow locks and alongside quays without interfering with the navigation of other vessels.

The flat open deck can transport up to four people or assorted payloads totalling 500 kg. Winches and tie-downs are incorporated into the deck to allow cargo to be easily secured.

The deck is of modular assembly to permit the transport of pallets or equipment if needed. Enclosures are also fitted to protect the cargo from the elements during transit.

Electric outboards coupled with autonomous and remote operating capabilities

The USV is equipped with an autonomous control system and is powered by a lithium-ion battery pack connected to two RAD 40 electric outboard engines, each with a rated output of 40 kW. The outboards can turn 90 degrees left or right to enable the craft to execute tight turns, while their low rpm will generate only minimal wake.

The standard propulsion arrangement delivers a sprint speed of 15 knots and cruising speeds of eight to 10 knots. With larger-capacity batteries, it will be possible for the craft to sail up to 40 nautical miles on a single full charge.

Concept proven through operational trials

RAD Propulsion and Williams Shipping conducted a six-week trial that demonstrated the electric outboards’ ability to deliver zero local emissions while having a low acoustic signature (just under 60 dB even at top speed) that enabled quieter operations and safer crew communication.

The USV was deployed at Williams Shipping’s homeport in Southampton, transporting tools, aggregates and crew over a distance of five kilometres (three miles) to support construction projects in the area. The Port of Southampton was selected for the trials due to its high volumes of vessel traffic, as the project partners had hoped to assess how the craft would fare when plying the same waters as larger commercial ships.

The autonomous control system on Willelectro was also proven to be capable of integrating with existing remote piloting systems, which RAD Propulsion said resulted in lower operational costs and crew workload. Operators monitored the USV’s performance from shore using an app-based interface while joystick controls will provide embarked personnel with an alternate means to navigate the craft besides the helm station.

With the trials having demonstrated the effectiveness of the concept, full-scale manufacture of other USVs with the same autonomous navigation systems and electric outboard propulsion is now scheduled to commence in the second quarter of 2026.