# Shanghai institute's bubble-lubrication system cut tanker net energy use by about 5% in trial

- Published: 2026-11-09 02:06 UTC
- Section: Power & Energy › Transport
- Tags: bubble-lubrication system, hull friction reduction, microbubbles under hull, product and chemical tanker, net energy consumption, ship fuel savings, compressed air hull lubrication, LNG methanol ammonia ships
- URL: https://realtech.media/news/rt-f34181ddbc54172fc13357c9_shanghai_institute_s/

**A second-generation system that injects air under the hull cut net energy use by about 5% in a five-month trial on a product and chemical tanker, the developers reported.**

![Shanghai institute's bubble-lubrication system cut tanker net energy use by about 5% in trial](https://realtech.media/media/2026/11/da81534b6f3de3e8.webp)
*Interesting Engineering*

The Shanghai Merchant Ship Design and Research Institute has reported that a second-generation bubble-lubrication system reduced net energy consumption by about 5% during a five-month operational trial on a newly built product and chemical tanker, according to scmp.com [1]. The tanker has since entered service [1]. The institute has not provided a detailed breakdown of the trial results [1].

## How the bubble-lubrication system works

The system injects compressed air beneath the hull and forms a layer of microbubbles between the hull and seawater [1]. This changes the flow of water near the hull surface and creates a gas-liquid mixture that lowers frictional resistance, so the ship may need less propulsion power to hold its speed [1]. The approach is related to the drag-reduction principle of high-speed underwater projectiles, which travel inside a gas-filled cavity, but the ship system uses a different implementation [1].

The first version was tested in April 2022 on a 1,800-TEU feeder container ship, and development of the upgraded system began the following month [1]. Engineers wanted to remove the earlier design's reliance on manual operation [1]. The new version has an improved air-supply structure intended to reduce compressor power consumption, and a control system that adjusts the volume of air according to the vessel's speed and draught [1]. A digital support system monitors and analyses energy efficiency in real time [1].

## Net saving and fuel estimate

The 5% figure is a net value: it accounts for the electricity consumed by the compressors that supply the air [1]. The institute estimates that such a reduction could save roughly one metric ton of fuel per day on a tanker of this size [1]. A separate retelling of the report gives an estimate of 1.1 tons per day for a vessel consuming around 22 US tons daily. This is a projection, not a directly measured trial result.

According to the institute, the system is compatible with ships powered by LNG, electricity, methanol and ammonia [1]. Wider adoption will depend on performance across different hull designs, operating conditions and routes.

## Sources

1. [scmp.com](https://www.scmp.com/news/china/science/article/3373333/chinese-engineers-reduce-cargo-ship-fuel-use-5-high-speed-torpedo-tech)
2. [Interesting Engineering](https://interestingengineering.com/energy/china-bubble-lubrication-system-energy-use)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-f34181ddbc54172fc13357c9_shanghai_institute_s/