There are gaps between the containers, then there is the bridge which can likely be outfitted with one
That said, fuel makes up 50-60% of the cost of shipping. So any reduction of cost can help. On top of that, many countries are passing laws that require reduction of local pollution when you enter their waters. So far they got around this by changing blends to less polluting ones, but these kind of restrictions will only get stricter
As for your other statement about "structural installation and maintainability, insurance costs, CO2, increased costs for certification society service of the sails existence", that is why they are testing the technology, this is a test.
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This is the ultimate point as to why it's being explored. News-flash to the right wing conspiracy theorists and even the hardline-left true-believers: companies don't generally care about emissions, only their bottom lines. Sure, they virtue signal and pay lip service to it, but this is mostly about appeasing customers and shareholders. However, as we've seen in the aerospace industry, when technological improvements that happen to cut emissions and boost efficiency also result in reduced fuel costs, companies will move heaven and earth to develop those technologies. In this case, the eco-friendly approach may ultimately also be the cost-saving approach. Add a gentle push from government to reduce pollution in famously choked port cities and maybe some emissions taxing, and you have even more motivation.
Quote from: Barros on March 21, 2024, 13:40:07Please allow me to be extremely sceptical regarding the 'science' behind this article. Given the high speed of modern freighters at >25knts it seems very implausible that sails could aid in the propulsion unless with a storm coming from the right direction. Not mentioned is the fact that oftentimes ships will be heading against the wind and the sails will be nothing but a handicap. Regarding the cost saving I also wonder if the amortization of the cost of the installation has been accounted for. Finally, do any of you hard-core navigators want to be on a ship in the middle of the ocean with a bunch of 40 meter high wind capturing stacks in a bad storm with 15m waves? I think not.
IMHO this is greenwashing at best.
Also, bit of a numbers-check on Barros: while newer ships can certainly travel as fast as you say, it is often very inefficient to do so. Most freighter ships travel between 13 and 24 knots on average, while most tanker ships travel in the lower half of this speed regime. When you consider average wind speeds throughout many parts of the Pacific regularly reach 15-20 knots, there is a fair bit of energy on offer here.
And here's the crucial bit that a lot of people misinterpret about sail-power:
you can continue to gain speed even when you are moving faster than the wind itself. This seems counterintuitive when you consider the "best-case scenario" being that the wind is hitting you directly from behind, but that's not actually the "best-case scenario" for sailing. It has to do with a bit of hard to visualize geometry in which, especially if the wind is hitting your sails from the side and slightly behind your direction of travel, the force applied to the sail gets converted to forward kinetic energy by the hull as it travels through the water, essentially acting like a lever. In this way, sailing ships have long been able to exceed wind speed by being clever about such factors as heading and sail orientation. With multiple intelligently self-adjusting sails that are able to adjust for optimal orientation automatically, using this phenomenon when able and putting themselves into a minimal drag orientation (sharp-side-in) when not, you can gain more energy than you lose throughout many different parts of your journey.