Germany’s manufacturer of propulsion systems Schottel has secured several orders to provide propulsion systems for US Navy vessels.
The order includes five workboat docking vessels and two YTL tugs – all of which are to be built at the Modutech Marine Inc. yard in Tacoma, Washington.
As explained by Schottel, the order represents a continuation of the collaboration between the company and the navy.
“The Schottel SRP installed on the navy’s existing YT 802 Class harbour tugboats have performed well and have proven to be reliable in service. Schottel has also provided good service and support for the thrusters. Therefore, we are looking forward to working with Modutech Marine and Schottel on the new YTL 815 Class tugs,” Dan Shimooka from the US Navy said.
Specifically, 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 rudder propellers will be equipped with the new nozzle SDC40, which combines compact design and high propulsion efficiency.
What is more, each of the Robert Allan designed YTL tugs will be propelled by two rudder propellers 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.
The design for the US 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 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.
Construction of the lead tug is to commence in 2020.