Beauty & Beast

Combining raw power and elegant design, tugboats are the workhorses of the maritime industry. They’re also leaders in the transition to a greener world.

Sparky the electric tug at sunset
The Damen-built electric tug Sparky, operated by Ports of Auckland (Ports of Auckland)

Published Jan 15, 2023 1:50 PM by Chad Fuhrmann

(Article originally published in Nov/Dec 2022 edition.)

They cut striking figures, at the same time remaining stalwart in their objective to provide dynamic power to the marine industry. The beastly-looking workhorses of the past have given way to sleek, modern designs that combine both beauty and power. These are not your grandfather’s tugs.

Like every type of vessel and every sector across the maritime world, however, they’re subject to the shifting tides of industry and impacted by the same regulatory changes and market fluctuations as the specific segments in which they work. While their various mission objectives remain unchanged, their means of propulsion have. And through collaboration with industry innovators, tugs continue to safely and effectively muscle their charges in a greener, more efficient way.

Raw Power

Few types of vessels are as globally universal as tugboats. Whether positioning huge ships in busy harbors, towing offshore structures for the energy industry or pushing extraordinary numbers of barges around a river’s hairpin turns, tugs are the workhorses of virtually every maritime sector.

By default, they fall squarely on the leading edge of progress in each of the sectors they serve.

With a power-to-weight ratio that can well exceed ten times that of much larger ships, tugs are built to convey raw power. However, in harbor applications, in particular, the impressively large power capabilities of tugs needed to guide and park large vessels are not needed 90 percent of the time. As a result, in conventional diesel-powered vessels, that power comes at the cost of efficiency and higher emissions.

According to Ferhat Acuner, General Manager of Naval Technologies Inc. (NAVTEK), based in Istanbul, research shows that as much as 40 to 60 percent of harbor and port emissions are the product of tugboat operations. With the increasing focus on carbon emissions, fuel efficiency and other environmental concerns, tugboats are championing new forms of power and design while still maintaining the necessary bollard pull.

Partnering with vessel designers and tech leaders, they’re collaborating on industry advancements in areas that are seemingly indirectly related to tugboats but directly impact their ability to perform their missions effectively.

Leading the Way

NAVTEK and its partners believe the marine industry is evolving in step with the world’s increasing focus on reducing emissions. With an eye on renewable energy sources and other efforts, governments and international organizations are now enacting strict environmental regulations, leading inevitably to the evolution of vessel design. Proactive companies see their role in this new future as recognizing and are seizing the opportunities offered by the immediate and long-term challenges of implementing green improvements.

With the increasing market focus on green technologies and the push to lower emissions, tugs are part of the focus of industry efforts to find ways of reducing or eliminating particulates while still providing the necessary horsepower when and where needed. As a result, NAVTEK proactively set a zero-emissions target for its tugboat designs, winning multiple awards for its ZEETUG, the world’s first fully electric, zero-emission, rechargeable tugboat that began operation in 2020.

With an annual reduction of up to 230 tons of carbon emissions, the ZEETUG has set the standard for others around the world. In a similar effort, the Ports of Auckland earlier this year welcomed the first “full size” all-electric tug, a Damen RSD-E Tug 2513 design, capable of reducing carbon emissions by over 500 tons annually while producing over 75 tons of bollard pull.

Both the Damen and NAVTEK designs are dependent on advanced battery systems that allow the vessels to run entirely without the assistance of diesel generators. Despite these and other groundbreaking tugboat designs, companies like NAVTEK aren’t nearly done. “We maintain the same passion to achieve even more,” states Acuner.

The tug sector’s trend away from diesel-fueled propulsion reflects the larger global pull away from hydrocarbons. But industry leaders such as e1 Marine, a marine hydrogen solution provider, say it’s only the beginning of a greater transition. “As part of the global energy transition to net zero,” states Managing Director Robert Schluter, “tugs and inland shipping face both a challenge and opportunity in managing the utilization of energy for propulsion. It requires solutions that maintain economic and operational performance.”

Vancouver’s Shift is another innovative company viewing energy transition as an unprecedented opportunity. Its overarching mission is to decarbonize the marine industry with what they believe to be a “combination of pragmatic solutions,” according to CEO Brent Perry. Shift focuses on industry segments that will have the most impact on this zero-emission objective, including tugboats, which it views as quintessential to servicing every port and city in the world in the escorting of all manner of vessels.

Whether in harbor applications or towing and pushing operations, Shift believes that energy storage is the ideal partner for tugs, able to optimize the use of fuel-driven engines during peak power requirements and 100 percent electric operation in transit. With unique services including PwrSwäp charging and battery swap stations strategically located, Shift is looking to facilitate not only energy storage system (ESS) installation on tugboats but also create the infrastructure to support all-electric operation – similar to ground transportation.

“Decarbonization and zero emission are the themes,” says Perry, “and Shift is leading the way, both in vessels that operate with zero emissions now and in charging systems that are going to trend to zero emission charging over the next six to nine years.”


During the transition between hydrocarbon-based fuels and their alternatives, Shift has been the thought leader at the earliest stages, bringing ESS to vessels in ways that deliver significant positive environmental and financial impact. Partnerships among Shift, its clients and other industry players have already improved the cost to customers through the benefit of zero-emission operations at less capital cost than building a conventional boat.

With all of the significant changes taking place, the industry’s energy transition requires significant collaboration within and across numerous sectors. Such collaborative efforts are critical to a smooth transition in the clean power movement that includes not only batteries but also renewable energy such as solar and hydrogen.

Partnerships such as that between e1 Marine and NAVTEK are working to bring hydrogen to the market as a feasible fuel alternative. With particular focus on the large number of existing marine internal combustion engines, a transition period is a must. The two companies are combining efforts to develop pragmatic hydrogen fuel cell technologies.

Like Shift, the efforts eschew a costly direct jump from one technology to another in the belief that fuel cells are “well positioned to meet the need for a safe, convenient and effective solution for achieving low to no pollution and meeting carbon emission targets” according to e1’s Schluter.

Faster transitions are afoot as well. Skipping diesel power entirely in a leap for the industry, e1 Marine’s methanol-to-hydrogen generator technology will be on display when the first of its kind Hydrogen One towboat enters service on America's inland waterways in 2023. Bringing all the players to the table, the Hydrogen One is being developed and built by Louisiana’s Maritime Partners and Intracoastal Iron Works, designed by Seattle’s Elliott Bay Design Group and operated by American Commercial Barge Line to move bulk liquid products around the Gulf Coast.

Across the tugboat sector, cooperation across commercial boundaries is seen as critical to the transition and evolution of the tug sector and the entire marine industry. According to Shift CEO Perry, “Collaboration is the key, sharing is the key, and support at all levels of business and society is critical if we are going to achieve our objectives.”

Driving Change

As the universal player in the maritime world, the tugboat industry is at the center of a changing industry and world. Despite the somewhat capricious attentions of marine markets and the general public, tugboats – as mainstays of the maritime world – must remain resolute in their mission and capability to serve the industry.

A primary competitive driver among the various industry partners centers not just on the reduction or elimination of emissions but on the potentially greater challenge of supporting a paradigm shift within the industry itself. “There was not a lot of institutional knowledge of this technology in the beginning,” notes NAVTEK’s Acuner, “but we are happy to have started this decarbonization journey at an early stage that has revealed some wonderful lessons for our company, our clients and our industry.”

In fact, rather than fight change, tug designers, operators and partners are embracing it, leading the charge in decarbonization by championing hybrid power plants and evolutionary leaps in propulsion power. “The maritime industry tends to be slow to change and hesitant to embrace first-mover status,” says e1 Marine’s Schluter, who sees tugboats serving as a linchpin for the rest of the industry. “Tug and barge operators, due to their coastal proximity, could move more quickly as the beacons to the rest of the maritime industry.” 

Chad Fuhrmann is a maritime consultant and the founder of Revolution Consulting X Engineering.

The opinions expressed herein are the author's and not necessarily those of The Maritime Executive.