[bunje]

I've analyzed performance data from air lubrication vessels with some retrofits included. Frankly, never witnessed over 5% gain. At specific velocity range the gain could be 5% on average if the installation has been really successful. They might be better nowadays.

[fredophile]

I'd imagine fuel costs are a big part of the cost of running a ship. Wouldn't a 5% gain be something ship owners would jump at? I realize it would be lower once you account for the added cost of the system and you may not always get 5% but even a savings of 1-2% of a big number is still a big number.

[zimpenfish]

> I'd imagine fuel costs are a big part of the cost of running a ship.

"A 12% reduction in at-sea average speed, known as “slow steaming,” led to an average reduction of 27% in daily fuel consumption and thus fewer greenhouse-gas emissions."

Slowing down sounds a lot easier and cheaper than retrofitting bulbous bows or fancy new air lubrication systems.

https://qz.com/1608527/the-shipping-industrys-emissions-coul...

[fredophile]

That does sound better but I think it would be harder to implement. Convincing people to accept later delivery times is tough. People don't want delayed gratification. US interstate speed limits used to be set to improve fuel economy due to the gas crisis in the 70s. Try to convince drivers that we should go back to a 55 mph speed limit.

[rsfern]

I agree with the conclusion, but daily fuel consumption isn’t the right thing to track.

I think this comes out to a 17% reduction in fuel use per unit distance, which still seems quite significant, but maybe changes the trade off point a bit.