The most popular class of bulk carriers (some 70%) are the mid-sized Handymax and Supramax with ~50 000 deadweight tons capacity, while employing a similar-sized crew of ~15. I honestly don't know what this clipper would need to carry to be profitable.
How to design a sailing ship for the 21st century?
41–50 of 90 posts
Re: How to design a sailing ship for the 21st century?
#42> However, by definition, the sailing ship is not a carbon neutral technology. For most of history, sailing ships were built from wood, but back then whole forests were felled for ships, and those trees often did not grow back. I do not understand this sentence. If I cut down a tree and do not burn it, isn't it a carbon neutral process? It did not release any carbon into atmosphere. By this logic is there any materia…
It will eventually rot and release its captured carbon.
All trees, even those which are not cut down for constructing a sailing ship, also eventually rot and release most of their captured carbon. Only those which are burned efficiently in a high-oxygen environment turn completely into CO2.
In a natural forest, it's true that a tiny fraction of this biomass derived from atmospheric CO2 rots incompletely on the forest floor and is turned into a small amount of carbon-rich soil, but this process is glacially slow. [1] suggests single-digit grams per square meter per year. Rotting on the seafloor may or may not be any better or worse.
Relatedly, carbon sequestration projects have biological carbon intake as one option. Instead of using industrial-scale chemical or electrical reactions to pull carbon from the atmosphere, use photosynthesis. Grow some trees, process them into ethanol and graphite, and bury the carbon-rich waste forever.
[1]: DOI:10.1007/978-3-540-92706-8_11 https://www.researchgate.net/publication/225314103_Soil_Carb...
Re: How to design a sailing ship for the 21st century?
#43It's a bit tangential, but I enjoy Moxie's (of Signal) stories relating to sailing. https://moxie.org/stories/together-two/
Re: How to design a sailing ship for the 21st century?
#44Earlier quoted context omitted.
Good news on the “weird turning-metal column effect” front: they just installed five tilting rotor sails on a newlybuilt bulk ore carrier. 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.
How does this work? The article assumes I should already know the mechanics of it, but googling only seems to turn up a bunch of the same sorts of articles.
I'm not an expert on it really. They rotate the giant cylinder and the wind is blowing by. The rotation forms a low pressure zone one side of the cylinder which acts as a lift force perpendicular both to the rotational axis of the cylinder and the wind.
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
Re: How to design a sailing ship for the 21st century?
#45> Lithium-ion batteries are very compact, but they cannot be considered sustainable and bring safety risks
C'mon this is silly. The dominant safety risk of a small vessel (and all of these are small in modern terms) is capsizing in heavy weather, with the loss of all hands.
LiFePO batteries, built into a bank with really excellent waterproofing, would be quite adequate to the job. If lithium battery technology in general proves to be unsustainable, we may as well pack up and go home, because decarbonization isn't going to happen.
Taking the average specific energy of LiFePO from Wikipedia, we get 12.5kg per kWh, almost five times denser for a proven technology you can buy off the shelf. 4.4 tonnes for the larger battery, compared to 9 tonnes for the smaller saltwater battery sketched out in the draft, and 21 tonnes for the larger one. That's 16.6 tonnes of additional life support the ship can carry; stowing a ship is a classic knapsack problem, there's no such thing as an "acceptable" amount of tonnage and volume to leave out of the equation.
Using saltwater batteries here would be an ostentatious stunt. Arguably that's what this whole thing is: an ostentatious stunt. But it doesn't have to be, it's a good proving ground for much larger sail ships, and a thousand tonnes here, a thousand tonnes there, pretty soon you're talking about real cargo. Electricity requirements should be very much sublinear with cargo capacity as well.
Re: How to design a sailing ship for the 21st century?
#46Earlier quoted context omitted.
Instead of sails we could try other methods, like kites, or that weird turning-metal column effect. To name two serious proposals I've seen
Good news on the “weird turning-metal column effect” front: they just installed five tilting rotor sails on a newlybuilt bulk ore carrier. 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.
From that article:
"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.
Re: How to design a sailing ship for the 21st century?
#47The most popular class of bulk carriers (some 70%) are the mid-sized Handymax and Supramax with ~50 000 deadweight tons capacity, while employing a similar-sized crew of ~15. I honestly don't know what this clipper would need to carry to be profitable. https://maritime-connector.com/bulk-carrier/
Ecotourists, and premium goods which advertise their cutting-edge sustainability.
Re: How to design a sailing ship for the 21st century?
#48> Lithium-ion batteries are very compact, but they cannot be considered sustainable and bring safety risks C'mon this is silly. The dominant safety risk of a small vessel (and all of these are small in modern terms) is capsizing in heavy weather, with the loss of all hands. LiFePO batteries, built into a bank with really excellent waterproofing, would be quite adequate to the job. If lithium battery technology in gen…
I've never sailed in blue water, but I thought that modern weather and navigation infrastructure mean bad weather can be largely avoided. Either way fire on board is still something to be avoided.
Re: How to design a sailing ship for the 21st century?
#49Maybe we could revisit what SkySails started https://en.wikipedia.org/wiki/SkySails
Re: How to design a sailing ship for the 21st century?
#50> Lithium-ion batteries are very compact, but they cannot be considered sustainable and bring safety risks C'mon this is silly. The dominant safety risk of a small vessel (and all of these are small in modern terms) is capsizing in heavy weather, with the loss of all hands. LiFePO batteries, built into a bank with really excellent waterproofing, would be quite adequate to the job. If lithium battery technology in gen…
I've never sailed in blue water, but I thought that modern weather and navigation infrastructure mean bad weather can be largely avoided. Either way fire on board is still something to be avoided.
Major storms can move faster than most sailboats can sail out of the way.