Three winterised escort tugs built for an Arctic terminal project have been heavily fendered to protect them and the gas carriers they were designed to escort from extreme weather and sea conditions.
Spanish shipbuilder Astilleros Gondán built three escort tugs – Pax, Dux, and Audax – for Østensjø Rederi to provide escort services to liquefied natural gas (LNG) carriers entering and leaving Statoil’s Melkøya production plant and terminal in Hammerfest, Norway. These tugs are expected to operate all year round in rough sea and weather conditions, but not in ice, due to the climate in the Barents Sea coast.
These RAstar 4000-DF design escort tugs have bow fendering consisting of a 1,000mm diameter cylindrical fender extending well aft along with a lower course of 400mm thick W-shaped fender, which was specially designed to limit fender contact pressures to 20 t/m2. According to designer, Robert Allan, sheer fendering is from a 400mm x 400mm D-shaped fender and stern fendering is a 400mm thick W-shaped fender.
In comparison, a Robert Allan-designed RAmparts 3200 class tug built for the Royal Thai Navy has a mixture of cylindrical, W-shaped and D-shaped fenders. Panyi, which entered service in March this year, has ship-handling fendering at the bow that consists of two rows of cylindrical fenders of 800mm and 400mm in diameter. A 500mm x 450mm W-shaped block fender is arranged below the cylindrical fenders. There are also 300mm x 300mm hollow D-shaped fenders to provide protection along the forecastle deck and the main deck sheer lines, and similar D-shaped fenders at the stern.