First US all-electric tug to run on Schottel propulsion

US ship owner and operator Crowley has contracted German propulsion manufacturer Schottel to supply a propulsion system for its first all-electric harbor tug eWolf.

The fully electric tugboat eWolf will be built by Master Boat Builders in Coden, using the design and on-site construction management by Crowley Engineering Services and its recently integrated Jensen Maritime naval architecture and marine engineering group. The 82-foot vessel will generate 70 short tons of bollard pull and “can complete a job without expending a drop of fuel,” Crowley claimed.

Now, as part of the fully integrated electrical package, Schottel will supply two RudderPropellers type SRP 430 featuring the LE-Drive. The SRP 430 LE is characterized by its compact design. Due to the extremely low installation height of the LE-Drive and the omission of the upper gearbox, the mechanical efficiency is expected to be increased by around 3 percent, and, at the same time, fuel consumption should be reduced, according to the company.

The eWolf will have a 6-Mwh energy storage system with sufficient capacity enabling the vessel to deliver one full day of normal work without using a drop of fuel. Batteries can supply power to the propulsion system almost instantly, ensuring effective ship support and harbour escort services without emissions.

Furthermore, the tug’s systems are designed for fast-changing load requirements. The vessel has two generators on board for emergency use and to enable longer transit distances at a reduced speed.

Beyond this, the vessel eWolf will feature MariHub, the IoT gateway and monitoring solution from Schottel. It records and analyses signals from sensors, machinery and other components, the company noted.

Together with the condition monitoring service ProCMS, MariHub is anticipated to detect any irregularities in the propulsion system. This predictive maintenance approach significantly increases the availability of the fully electric vessel: ProCMS is able to support the operator’s achievements in reducing maintenance costs and improve maintenance planning, according to the partners.

“The eWolf’s zero-emissions design features a propulsion system that will provide a sustainable ship assist solution with enhanced safety and nimble manoeuvring capabilities,” Joshua Ellis, Vice President, Ship Assist Services at Crowley.

The tug is scheduled to enter operations by mid-2023 and it will support ship arrivals and departures at the Port of San Diego in California.

Earlier on, the German firm revealed it has committed to net-zero greenhouse gas (GHG) emissions across all scopes by 2050, pursuing a path aligned with the International Maritime Organisation’s (IMO) zero-emission targets.