Studies by Simpson, Spence and Young, a leading global shipbroking firm, seem to indicate that emission benefits of slow-steaming have been exaggerated.
One reason offered is that the ‘cubic law’, which says that fuel consumption rises as the cube of ship speed, is erroneous for many vessels, and is only approximately true at the designed speed of the ship.
Another problem is that slow-steaming effectively reduces capacity, requiring more ships to cover a route with a regular schedule, for instance. Those extra ships produce more emissions even though the per-ship emissions might be smaller.
Capacity is not a problem at present. There’s not enough cargo. But scheduled service may suffer.
There are a lot of moving parts in considering emissions release.
The best way to attack the problem may be to get to zero or low-emission ships as quickly as possible. But in the short run, these considerations in he study are worth thinking about.
By Charlie Bartlett, technology editor 15/05/2023Benefits of slow-steaming on emissions exaggerated, studies find – The Loadstar