Korean harbour tugs do the job

The ports of Daesan, Taean and Boryeong are set over a 15-mile expanse and handle a variety of ship types including container ships, petroleum tankers and deep draught coal bulk carriers. In addition to the diversity of shipping, the rugged coast has a tidal range that can extend vertically up to nine metres with routine cross currents of two to three knots.

The associated ports are served by several towage companies, one of which, Haeyang Shipping, operates four tugs and is currently building an additional tug at its own yard, Haeyang’s Geumgang Shipbuilding. The newbuilding is a slightly larger sister ship to the six-year-old Haeyang No.7 which has a length of 32m and an 8.7m beam.

For propulsion power and manoeuvrability, the tug has a pair of Cummins KTA50-M2 high speed diesels each delivering 1,322kW to Schottel SRP 1010 rudderpropellers. The drive shafts to the aziumthing propulsors include a section of cardon shaft and a Centraflex mount with several bearings. The engine room is monitored from a separate control room in which the electrical bus is located.

The new $4 million vessel currently under construction will be slightly longer at 33m overall with a 29m length on the waterline and the same 8.7m beam. Engines for the new boat were supplied by STX Engine Company, the Cummins dealer for Korea. It will have the same Cummins KTA50-M2 engine package delivering a total of 2,645kW to power the Schottel SRP 1012, an updated version of the SRP 1010. This combination will give the boat a 13.5 knot speed at 100% MCR and a 12 knot service speed.

The Haeyang harbour tugs are designed by Inchon-based naval architect firm Kumho Marine Engineering. As the current vessel is being built for domestic use it will be classed by the Korean Register of Shipping. Sea trials for the newbuilding are expected to be carried out in April 2010.