GILLS PTE wins BV air lubrication system approval

Singapore-based company GILLS PTE has secured Approval in Principle (AiP) for its GILLS Air Lubrication System from the classification society Bureau Veritas.

The company has developed a gas-injected liquid lubrication system (GILLS) to drive energy efficiency and reduce fuel consumption in the shipping industry. As disclosed, the fuel savings achieved by the system reach approximately 10 percent.

“The GILLS systems have been installed on an existing vessel for a number of years now and the vessel owners are confident that the fuel savings are approximately 10%,” David Barrow, SE Asia Zone Vice-President for Bureau Veritas, said.

Their air lubrication system deploys NACA profiles to create self-generating microbubbles of air for ‘turbulent modulation’ which has a ‘hull-tightening’ effect. The air release units reduce the frictional resistance between the ship’s hull and the water, improving the overall ship efficiency and decreasing the fuel consumption.

The GILLS system can be built into new ships or retrofitted on the existing ones.

“The GILLS Air Lubrication System is a nature based innovative technology that not only uses the micro bubbles to reduce the drag, emissions, fuel and biofouling, but it also utilizes the ship speed to generate a negative pressure and minimizes the required external compressor power,” Peter Kneipp, Managing Director of GILLS PTE LTD, said.

Different factors and forces of GILLS hull tightening effect technology are acting on the microbubbles generated by a GILLS vortex generator installed at the bow of the ship, with the following features:

1. A ship’s forward movement
2. Creation of microbubbles by negative pressure and Kelvin Helmholtz Instability (KHI) exiting the vortex generator
3. The random shape of microbubbles with turbulence, eddies and vortices, from KHI
4. Buoyancy acting on the micro bubbles inducing an upward force
5. Shape of the hull.

By reducing the fuel burn, this type of system can contribute to lowering emissions in the shipping sector and help achieve the International Maritime Organisation’s (IMO) goal of reducing emissions by at least 50 percent by 2050.

Further on, the company’s system improvements are in line with the IMO’s EEDI/EEXI energy efficiency targets.

To remind, in November 2020, IMO approved amendments to MARPOL Annex VI, introducing an Energy Efficiency Design Index for existing ships (EEXI). 

This means that Energy Efficiency Design Index (EEDI) limits would be implemented to existing ships and a rating mechanism to mandate improvements to the operational carbon efficiency of ships.

Subject to adoption at MEPC 76 in June 2021, the requirements will enter into force in 2023. The EEXI will be applicable for all vessels above 400 GT falling under MARPOL Annex VI.

“The collaboration with GILLS is timely as the industry seeks performance improvements in line with the EEXI energy efficiency targets. Pressure is building to find cost-effective solutions that work and can be financed,” Barrow added.

“We are greatly confident that GILLS will be a valuable contributor for practically every ship type to improve the EEDI /EEXI IMO Index,” Kneipp noted.

The AiP covers the design of the system and installation onboard vessels as reviewed against the Bureau Veritas Rules for Steel Ships NR 467 (as updated in January 2021).

Barrow added that the next step will be a full-scale measurement and a validation exercise led by Bureau Veritas Solutions (BVS) to identify confirmed performance.

“BVS, our consultancy arm, is also working with GILLS to assess the potential of access to Singapore ‘Green Funds’ to provide financial support to owners considering using such energy-saving systems,” he concluded.