Wallenius Wilhelmsen’s ro-ro vessel Aniara has been fitted with an upgraded bulbous bow.
Installed at the IMC-Yongyue (IMC-YY) repair yard in Zhoushan, China, the process was executed within the anticipated three-week dry-docking span.
Adam Larsson, senior manager of energy efficiency and performance, said: “The existing bulbous bow design was initially optimised for one very specific draught and speed. However, operational data clearly show that the vessels operate at lower draughts and speeds a significant portion of the time, where the existing design is not performing well, creating additional resistance to move through the water.”
Teaming up with design partners DSEC and DSME/Hanwha, Wallenius Wilhelmsen developed an optimised design that reduces resistance and promises considerable fuel savings. These fuel savings amount to an average of 6 percent, translating to a reduction of 1,400 tonnes of CO2 annually for a single vessel.
“We can expect even larger average savings if actual operating speeds are reduced in the future because the new design compared to the old will perform much better at lower speeds. Worth noticing is that at some operating conditions, such as lower draught about 8 m and 14 knots speed, the savings can be as much as up to 30 percent,” added Larsson.
The 137-tonne, 23 m bulbous bow section underwent a two-month pre-fabrication phase, when it was coated and lifted into the dry dock using a large floating crane before installation.
Similar enhancements will be rolled out for the ro-ro vessels Oberon, Tijuca, and Tirranna.
