The five tugs were designed by Vancouver-based naval architecture firm Robert Allan Ltd (RAL), however they cover two distinct designs, says RAL. The Jin Gang Lun 28 and Jin Gang Lun 29 were RAstar 3500 class tugs, however their predecessors, the Jin Gang Lun 26 and Jin Gang Lun 27 were both RAmparts 3500 series tugs featuring a different hull form.
RAL says that as a result of an internal research and development program utilizing computational fluid dynamics simulations the roll angle and roll acceleration of the RAstar tugs were calculated to be about 22% and 12% lower, respectively, as compared to the RAmparts series.
The CFD simulations were carried out at a design speed of 14 knots in beam seas of irregular waves.
- Notation: China Classification Society – FiFi 1, CSAD, Tug, Coastal Service, Ice Class B, CSMD, BRC
- Length O.A.: 35.00 m
- Beam, moulded, extreme: 12.40 m
- Depth, moulded (hull): 5.40 m
- Maximum Draft: 4.22 m
- Propulsion: (2) Niigata 8L28HX; 2206 kW at 750 rpm
- Thrusters: (2) Kawasaki, KST-220ZC/B-2.7 controllable pitch
- Electrical: (3) 100 ekW diesel gensets
- Fuel Oil: 183 m³
- Fresh Water: 30 m³
- Foam: 20 m³
- Crew: 14
- Bollard Pull: 74.5 tons
- Free running speed: 14 knots
The deck machinery comprises two ship-assist hawser winches forward, and a tow hook on the aft deck. In addition, a capstan is installed aft to facilitate line handling operations.
Ship-handling fenders forward consist of one row of 700 x 350 cylindrical fender at the main deck lever, with 600 x 400 mm M block fenders between the main deck and the knuckle. Steel half pipe fenders with elements of 400 x 400 “D” fender provide protection at the main and foc’sle deck sheer lines, and a 500 x 250 cylindrical fender is used at the stern.
All images and drawings courtesy Robert Allan Ltd.