Propulsion selected for newbuild US pusher tugs

Silverback Marine is building a series of aluminium pusher tugs in the USA for the nation’s Department of Defense to be used on inland waterways.

These tugboats will be built to a compact design for transport between destinations on lorries, with an overall length of 8 m, a beam of 4 m, and a bollard pull of around 7 tonnes.

Spay, Germany-headquartered Schottel will supply its RudderPropellers of type SRP 100, two for each of these OX series tractor tugs, with deliveries expected later this year.

Silverback developed this series, in collaboration with Seattle-headquartered Elliott Bay Design Group, to be highly manoeuvrable and compact for use in US waterways.

“We spent a little over three years refining the design of the OX series, and a huge part of this was identifying key vendors we could be confident in,” said Silverback Marine chief executive Ian Gracey.

“Part of our approach was to consult not only highly experienced and seasoned tug captains, but also mechanics servicing tugs. We identified consistent trends: a strong emphasis on manoeuvrability, user experience and performance.”

Each of the 360° steerable SRP 100 azimuth thrusters has an input power of 216 kW, a propeller diameter of 850 mm and enables space-saving installations on these tugs.

Silverback said these compact tugboats, with a minimal draught, will be used for towing and pushing activities, “and can be easily transported to job sites by a lorry and will perform operations normally only possible with much larger tugs.”