Crowley unveils autonomous electric-powered tug

Naval architects have developed a design for a 25-m tug with a package of batteries, power-saving technology, electric motors and azimuth thrusters for manoeuvring ships in US ports. With a bollard pull of around 70 tonnes, it will produce almost zero emissions from its azimuth stern drive propulsion.

Its battery of energy storage devices has a capacity of up to 6 MWh to run two azimuth drives, each with power input of 1,800 kW, to deliver speeds up to 12 knots.

Crowley Engineering Services vice president Ray Martus said this design would cut emissions in tug services in ports. “Our design provides operators the tugboat solution to continue serving ships quickly and powerfully, while reducing their environmental impact by eliminating a carbon footprint,” he said.

“This new design sets the standard for innovation by showing that sustainability and power can work together seamlessly in our maritime industries.”

Crowley’s tug design has a moulded breadth of 12.1 m, a 5.4 m hull depth and a 4.9-m draught, can be customised for owners’ requirements and upgraded in the future with different operational features such as hybrid propulsion. Onboard batteries can be upgraded as electric technology changes.

In addition, Crowley has developed an onshore charging station to support charging and reliable performance at the tugboat’s home port.

With no exhaust stack, the tug has 360° of visibility from the master’s station without obstruction.

Crowley designed this electric tug for future autonomous operation to increase safety by including integrated automation and control systems. Intelligent manoeuvring and control systems will enable the master to focus holistically on the overall control and positioning of the vessel in increasingly busy harbours.

On the deck, this electric tug could have a bow or stern towing winch and/or a render/recover winch. With accommodation for four people, it has a fresh water storage capacity of 3,410 litres.

In February 2021, Crowley integrated its design house Jensen Maritime into its engineering division to expand its overall naval architecture services.

Alternative fuels, hybrid propulsion and autonomous technologies will be discussed during Riviera Maritime Media’s series of virtual webinars, forums, conferences and technology days in 2021 - use this link for more details and to register on the events page