Crowley Designs US' First Fully Electric Autonomous Tug

Crowley Engineering Services announced Monday it has designed the first fully electric U.S. tugboat with autonomous technology, engineered as a zero-emissions, high-performance solution for ship assist and harbor services.

The Crowley design, powered by the expertise of recently integrated subsidiary Jensen Maritime, leverages a large battery system and power saving technology to operate in a fully electric mode while producing zero air emissions or greenhouse gases, Crowley said. The 82-foot ship assist tug features an Azimuthing drive propulsion system with two 1,800 kW motors and a 6 MWh battery, providing an estimated 70 short tons of bollard pull. The vessel also has two small generators for emergency use and to enable the vessel to transit longer distances at a reduced speed.

The innovative tug was sized and designed to complete two ship assist jobs in the harbor with minimal to no charging required. The platform design can be adjusted for alternate power capacities suitable for a standard hybrid framework if desired. The battery system is modular and can be maintained and upgraded for future battery technology improvements without any significant modifications to the vessel.

In addition, Crowley has developed an onshore charging station to fully support charging in port.

“Crowley’s design provides operators the tugboat solution to continue serving ships quickly and powerfully, while reducing their environmental impact by eliminating a carbon footprint,” said Ray Martus, vice president, Crowley Engineering Services. “This new design sets the standard for innovation by showing that sustainability and power can work together seamlessly in our maritime industries.”

With no exhaust stack, the tug has 360 degrees of visibility from the pilot’s station, allowing the operator to see without obstruction.

The tug has also been designed for future autonomous operation to increase the safety and efficiency of the operation including integrated automation and control systems. The intelligent maneuvering and control system offers more efficient vessel operations and allows masters to focus holistically on the overall control and positioning of the vessel in increasingly busy harbors, Crowley said.

The tug is designed to ABS Class and compliant with U.S. Coast Guard Sub-Chapter M regulations.

Molded Length: 82’
Length at Waterline: 78’ 4”
Depth: 17’ 9”
Design Draft: 16’
Beam: 40’
Bollard Pull: 70 short-tons (estimated)
Speed: 12 knots
Gross Tonnage (US Regulatory): <200 GRT
Main Propulsion: 6 MWh battery, Azimuthing drive, 2 x 1800 kW electric motors
Bow Winch: 40HP Electric Render/Recover Winch
Stern Winch: 40HP Electric Render/Recover Winch
Fuel: 9800 gal at 95%
Fresh Water: 750 gal
Berths: 4

(Image: Crowley)