Turkish shipbuilder Sanmar Shipyards is building a trio of 70-tonne bollard pull tractor tugs that were specifically designed by Canadian naval architects Robert Allan. These Deliçay-series tugs will have Rolls-Royce US 255 drives and will be ready for delivery in February 2018.
Robert Allan has developed two types of 25 m tugs for Sanmar. The ones under construction will be based on the TRAktor 2500-SX design with an aft working deck. Robert Allan also developed the ART 60-25SX design 25 m Rotortug with both fore and aft working decks and 60 tonnes of bollard pull.
Both designs were developed with analysis using computational fluid dynamics, of which Robert Allan uses CD Adaptco’s software, and model testing at the Vienna Model Basin. These were used to “obtain an optimal balance between controllability, manoeuvrability, fuel efficiency and roll dampening,” according to Robert Allan.
For the trio under construction, StRAke stabilisers developed by Voith and Robert Allan are added to the stern section of the hull. These “improve tractor tug directional stability allowing for a reduced size skeg and thereby improving manoeuvrability and fuel efficiency”.