Watch Now


Crowley developing first fully electric tugboat in US

Port of San Diego to gain electric tugboat in 2023

(Photo: Crowley Maritime Corp.)

The first fully electric U.S. tugboat is set to operate at the Port of San Diego’s Tenth Avenue Marine Terminal by mid-2023, the manufacturer announced Monday.

Crowley Maritime Corp.’s 82-foot eWolf vessel will have 70 tons of bollard pull and release zero tailpipe emissions. It will have 360 degrees of visibility from the pilot’s station and is being designed for potential autonomous operations in the future. This eTug will replace a conventional tugboat that consumes more than 30,000 gallons of diesel annually, Crowley said.

“The eWolf represents everything Crowley stands for: innovation, sustainability and performance. With this groundbreaking tug design, our team continues to embrace our role as leaders in the maritime industry while providing our customers with innovative and sustainable solutions done right,” Chairman and CEO Tom Crowley said in a statement.

In comparison to a conventional tugboat, in its first 10 years, the eWolf is expected to reduce emissions by the following levels:


  • 178 tons of nitrogen oxide.
  • 2.5 tons of diesel particulate matter.
  • 3,100 metric tons of carbon dioxide.

“The tug was originally designed to complete two standard ship assist jobs in a row without charging or utilizing the backup generator. The eTug is designed to serve harbor and ship assist comparably to current conventional tugs — without any emissions,” Josh Ellis, Crowley’s vice president for harbor escort and ship assist services, told FreightWaves.

A shoreside energy storage system developed with Cochran Marine will charge the eWolf’s battery system. The system will have 3 megawatts of battery capacity, which will enable fast charging between jobs, Porter Sesnon, director of business development at Crowley, told FreightWaves. He said solar panels will also be incorporated to charge the eTug with renewable energy.

“While lithium-ion batteries have reduced in price dramatically over the last decade, there will need to be further cost efficiencies to make more boats more feasible for operators to meet sustainability demands as well as the needs of markets where we operate,” Sesnon said.

Sesnon said the cost of the battery system is the biggest challenge the company faces in the electrification process for the eWolf. He noted the project wouldn’t have been possible without the support of Crowley’s partners.


“Crowley’s first-of-its-kind electric tugboat is a game changer. It checks all the boxes by providing environmental, economic, and operational benefits for our communities and maritime industry,” Michael Zucchet, chairman of the Port of San Diego Board of Port Commissioners, said in a statement. 

Financial supporters and resource providers for this Crowley eTug project include:

  • The San Diego County Air Pollution Control District.
  • The California Air Resources Board.
  • The Port of San Diego.
  • The Environmental Protection Agency.
  • The U.S. Maritime Administration.

“We envision the eWolf to be the first of multiple additional eTugs that can be deployed and adapted based on individual port needs and alternative energy sources. … With the industry’s demands for sustainable operations and decarbonization, the design package can be replicated in multiple ports — especially when coupled with the shoreside solution developed for the eWolf,” Sesnon said.

Click here for more FreightWaves articles by Alyssa Sporrer.

Crowley gifts $2.5M to University of North Florida for transportation, logistics

What is well-to-wake emissions analysis?

Shipping groups want action on $5B fund for zero-emission fuels, tech

FreightWaves Classics: Crowley Maritime Corporation … from a single rowboat to a global leader


Alyssa Sporrer

Alyssa is a staff writer at FreightWaves, covering sustainability news in the freight and supply chain industry, from low-carbon fuels to social sustainability, emissions & more. She graduated from Iowa State University with a double major in Marketing and Environmental Studies. She is passionate about all things environmental and enjoys outdoor activities such as skiing, ultimate frisbee, hiking, and soccer.