https://gcaptain.com/newbuild-vale-vloc-revealed-as-bulk-car...
Why is this important? It shows that the ship owners has seen enough promise in the technology to overcome the potential risks. If it works out well for them we will very likely see wider adoption.
"If the pilot proves effective, it is estimated that at least 40% of the fleet will be able to use the technology, which would result in a reduction of almost 1.5% of Vale’s annual iron ore maritime transport emissions.”
Well, that's a step in the right direction so something to be applauded. But taken alone, an emissions reduction of "almost 1.5%" isn't going to save the planet.
It's the same effect which "turns" a soccer ball if you kick it with a spin. There is a really nice demonstration of the effect in this video: https://www.youtube.com/watch?v=2OSrvzNW9FE
This wikipedia page has a way better summary than my attempt above: https://en.wikipedia.org/wiki/Rotor_ship
In fact, doing such would provide a buffer that could help prevent supply shocks.
Oceangoing ships have a relatively short useful life...salt water is rough on metal.
Unfortunately though, sail driven ships are kind of useless for the efficient movement of cargo. Masts are required and take away stowage space and, more importantly, make efficient cargo loading/unloading impossible. Read the book "The Box" to understand the changes brought about in cargo shipping over the last century.