Schottel has secured several orders to provide propulsion systems for five "workboat docking" vessels and two YTL tugs for the US Navy, all of which are to be built at the Modutech Marine yard in Washington.
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 metres 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.
Each of the Robert Allan Ltd-designed YTL tugs will be propelled by two Schottel SRP 270 FP rudderpropellers with a propeller diameter of 1.85 metres 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 US Navy surface ships, submarines and barges.
The 19.2-metre by 9.4-metre 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.
