Wind assisted power spreads its wings

Wing technology will be installed on 14 LR2 tankers, 12 chemical tankers, and eight MR tankers. And BAR claims each sail will reduce carbon emissions by six tonnes on a typical trade route.

“This propulsion technology has huge environmental benefits as well as economic incentives for shipowners and charterers alike – as well as the wider shipping and trading community – in the form of significant reduced fuel costs,” said a BAR statement.

The new vessels will also sport the aero dynamically designed bridge and accommodation block, which is shaped like to wings with a horizontal bridge sitting on top of the structures.

BAR Technologies sales director Tom James said: “When you analyse the performance of WindWings you have to consider the interaction effect of the wings and the ship.”

James said the newly designed bridge and the hydrodynamically optimised hull will save up to 12% in fuel consumption. But he was keen to emphasise that it was the overall performance of the all the constituent parts of the system and the way they interacted that would ultimately give an accurate account of fuel consumption reductions.

It was with this in mind that DNV has devised a methodology for measuring the changes in vessel performance when wind power is introduced.

Related:MOL targets 80 wind propulsion installations by 2035

The system is called the on/off test, which was first applied to the Cargill vessel, the Pyxis Ocean.

Essentially, the test includes measuring ground and water speed with shaft power and comparing that with the wings in operation to having no wing power at all. The on/off test revealed a 31.8% power reduction on the Pyxis Ocean with sails operable with an increase in speed.

The wingsails themselves are manufactured in China with a steel structure, with the surface area of lightweight glass composite, similar to wind turbine blades, with the wing weighing in at 200 tonnes and the plinth on which it sits adding 40 tonnes.

James said that there will soon be strain gauges to measure the loads on the sails and plinth in varying weather conditions.