​​​​SCHOTTEL to Equip US Navy Tugs

SCHOTTEL said it has secured several orders to provide propulsion systems for U.S. Navy vessels. 

This additional order of five Workboat Docking vessels and two YTL tugs – all of which are to be built at the Modutech Marine Inc. yard in Tacoma, Wash. Construction of the lead tug is to commence in 2020.

The main propulsion for each Workboat Docking vessel consists of a SCHOTTEL SRP 150 azimuthing unit with fixed pitch propellers with a diameter of 1.05 m and an input power of 335 kW. These are driven by diesel engines. The rudderpropellers will be equipped with the new high-efficiency nozzle SDC40, which combines compact design and high propulsion efficiency.

Each of the Robert Allan designed YTL tugs will be propelled by two SCHOTTEL Rudderpropellers type SRP 270 FP with a propeller diameter of 1.85 m and an input power of 970 kW. They will be powered by diesel engines. With this propulsion system, the vessels achieve a free running speed of approximately 10 knots and an expected bollard pull of 32.7 tonnes.

With medium-sized rudderpropellers such as the SRP 270, SCHOTTEL is meeting new challenges in the international maritime market. These include shifted engine power classes, new ice class rules and the growing trend towards electric or hybrid-driven vessels. Combining the latest technologies in mechanical engineering, hydrodynamics, and digitalization, the medium-sized thrusters are available in three sizes which correspond to common engine power classes: SRP 210 (640 kW), SRP 240 (850 kW) and SRP 270 (1,000 kW).

The design for the U.S. Navy will also include updates to suit new EPA Tier 4 engines and associated systems while also featuring extensive fendering above and below the waterline to handle U.S. Navy surface ships, submarines and barges. The 19.2 m long and 9.4 m wide tugs are essentially configured as “day-boats”. Nevertheless, they also provide accommodation for a crew of up to four persons.

Photo: SCHOTTEL