Propulsion manufacturer Schottel will supply its proprietary rudder propellers for Brazilian towage group Starnav’s four newbuild tugs
Each azimuth stern drive tug will feature two diesel-driven Schottel rudder propellers type SRP 490 at 2,525 kW each, featuring fixed-pitch propellers with a diameter of 2.8 m. With this thruster configuration, they will achieve more than 80 tonnes of bollard pull and a maximum speed of 12.5 knots.
One of the 32-m by 11.6 m escort tugs will feature Schottel’s patented Sydrive-M technology from the start while the other three will be configured to be Sydrive-ready.
Sydrive is a mechanical hybrid drive system without the costly complexity of common hybrid technology, to help lower maintenance costs and fuel consumption.
Starnav chief executive Carlos Eduardo Pereira said, “By using Schottel’s hybrid solution, we seek clean operations. Starting now is particularly important: the vessels that are built today will be in the water for decades to come.”
“Our focus has always been the high level of reliability in the equipment, mainly safety and environment care. With 34 vessels propelled by Schottel in our fleet, we will continue expanding our operations and benefit from a strong partner with extensive know-how in Brazil.”
The Sydrive-M connects a port and starboard-mounted azimuth thruster in one vessel, allowing the thrusters to be driven together by only one of the main engines. The system needs no additional electronical components, which offers many advantages as demonstrated in three main operation modes: light operation or free sailing mode, full thrust operation mode and FiFi mode.
In turn, the configuration helps reduce the operating hours of the main engines and results in lower maintenance costs and reduced carbon emissions.
Starnav has contracted Detroit shipyard in Itajaí, Brazil to equip the tugs with the Schottel rudder propellers. The first of the four tugboats is scheduled to enter service in 2022.