Schottel propulsion picked for Silverback Marine’s tug

The vessel, which is under construction for the US Department of Defense, will be powered by two Schottel RudderPropellers type SRP 100. Delivery is anticipated in late 2025.

The compact tug has been designed in collaboration with Elliott Bay Design Group, headquartered in Seattle. With a length of just 7.9 metres and a beam of 4.4 metres, the truckable tug will deliver a bollard pull of nearly seven tonnes, making it highly manoeuvrable while occupying a minimal footprint.

According to Silverback Marine CEO Ian Gracey, the choice of Schottel followed an extensive development and evaluation process. “Silverback spent a little over three years refining the design of the OX, and a huge part of this was identifying key vendors that we could be confident in,” he explained. “We consulted not only highly experienced tug captains but also mechanics servicing tugs. We identified a consistent trend of both captains and mechanics expressing appreciation for the Schottel product. A strong emphasis on manoeuvrability, user experience and performance seemed to trend towards Schottel as the top choice in tug propulsion.”

Gracey also noted Schottel’s reputation for after-sales support and reliability. “Every boat to sail the seas needs regular maintenance and support, and Schottel has definitely established itself as a leader in that respect. Our team is passionate about bringing a new era to the mini tug market, and Schottel has clearly proven itself to be the partner of choice for not only Silverback but, more importantly, our customers.”

The two SRP 100 azimuth thrusters each feature an input power of 216 kW and an 850 mm propeller diameter. Their 360-degree steerability ensures maximum manoeuvrability and efficient propulsion in a design that integrates seamlessly into the tug’s limited dimensions. The compact nature of the thrusters allows for a space-saving installation while delivering powerful performance.

The tug has been engineered to support towing and pushing duties typically assigned to much larger vessels. It can be easily transported to remote or challenging job sites by truck, offering a combination of agility, shallow draught, and robust performance. With its adaptable design and advanced propulsion package, the OX series tug represents a new generation of versatile, compact workboats tailored to modern operational needs.