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I love that they're trying this. It appears the more practical goal might be retrofitting existing vessels with large sails to augment the motors, but making a

I love that they're trying this. It appears the more practical goal might be retrofitting existing vessels with large sails to augment the motors, but making a point with a fully wind-powered vessel is a good show. Well, it would have been fully wind powered if not for the damaged sail. Good on them for sticking with the journey, though. I hope they keep running the vessel and get a few more fully wind powered journeys.

defrost 1y ago
I have a dim recollection of exactly this as a VC proposal likely put to YC in the past 24 months or so. I think the notion was to fit masts to existing container ship and stacks, and I gsve it scant attention as my intuition (I once studied actual civil/mech engineering prior to jumping ship for applied math) suggested masts are better as integral parts of ships rather than bolt on after thoughts. EDIT: Wingsails to reduce cargo ship fuel consumption (April 2023) https://news.ycombinator.com/item?id=35426482 https://news.ycombinator.com/item?id=35426482 I’m Joseph, and along with Arpan and Bailey we are the founders of OutSail Shipping. We’re building a sail the size of a 747 that rolls up into a shipping container. https://outsailshipping.com/ https://outsailshipping.com/ https://www.linkedin.com/company/OutSail-Shipping/ https://www.linkedin.com/company/OutSail-Shipping/ When deployed, it will generate thrust from the wind to reduce the fuel consumption of a cargo ship. An array of these devices will reduce fuel consumption on ships by up to 20%. These sails are easily stowed and removed to cause no interference with cargo operations. Here’s a short video showing our prototype: https://www.youtube.com/watch?v=VUpVqzpym54 https://www.youtube.com/watch?v=VUpVqzpym54 Not quite as I remembered .. kite sails, et al. are a good idea, I'm still a bit torn by the physics of a container deployed boom extension sail and the thrust transmission to the ship. Still, I haven't modeled it, so take my thoughts with a grain of salt. EDIT2: Both links appear dead, so I guess that was a swing and a miss. Still, good to see such ideas pursued. EDIT3: Also related 350 tons of of chocolate and wine arrive on world’s largest cargo sailboat (April 2024) https://news.ycombinator.com/item?id=40022801 https://news.ycombinator.com/item?id=40022801
- tengwar2 1y ago
  This is an area I have some peripheral involvement with. For retrofitted sails on bulkers, the figure of 10% saving in fuel is the usual one mentioned rather than 20%. However given the long life of ships, there is much more interest in retrofit than in new build. You mention container ships. I haven't seen anything explicit on these, and I think the reason is probably that they cruise much faster than bulkers and tankers, which means the potential savings from sail is smaller. I would have thought 20% optimistic even for a new-build.
  - defrost 1y ago
    Retro fit is clearly a preferred path for a new approach given ship life spans and size of existing global transport fleet. My gut objection to the container approach taken above in the first link was existing container locking mechanisms for ships can struggle in severe weather to keep the boxes on the boat .. additional forces from a sail (in good weather) might well mimic the forces that break stacks in bad weather. Your point is well taken, I might suggest that container ships could be segregated into fast and slow cargo and that might help somewhat with total fleet fuel consumption. (pure spitball notion).
    - Maxion 1y ago
      I'm sure there's plenty of businesses out there who'd love to advertise near zero or zero emissions transport for their goods, with the caveat that they have to plan a few more months ahead.
- komali2 1y ago
  Wasn't the main issue with this that fuel is paid for by cargo ship customers (the container owners), not the shipping company? So the shipping company doesn't want to spend a ton of capital to get a 10% discount to all their customers, and there was no way for thousands of random customers to exert pressure on the shipping company to do so. Basically the economics didn't make sense.
  - 1y ago
JeremyNT 1y ago
Rotor[0] retrofits already have been done on full size tankers[1]. This is probably a more reliable and practical solution than traditional sails. 0 https://en.wikipedia.org/wiki/Rotor_ship https://en.wikipedia.org/wiki/Rotor_ship 1 https://en.wikipedia.org/wiki/Maersk_Pelican https://en.wikipedia.org/wiki/Maersk_Pelican
- cl3misch 1y ago
  But why would you use a motor to spin a rotor instead of a submerged propeller?
  - Ekaros 1y ago
    No mechanical linkage. Basically just installing rotor on top of the deck and some electric connections are needed. Much simpler and much less error prone. Plus keeps all the usable space on decks below.
  - deleted 1y ago
    [deleted]
  - jna_sh 1y ago
    Seems an interesting solution to whales being cut up by ship propellers
  - wongarsu 1y ago
    Spinning the rotor allows you to generate more power from the wind than what you would have gotten by putting the same energy into spinning a submerged propeller. From what I understand it's not hugely more efficient, but something like 10-20% fuel savings. Not really equivalent to traditional sails, but also much easier to retrofit and doesn't need additional crew
  - speed_spread 1y ago
    For the same reason you use electricity for a compressor in a heat pump. It's a lever. You extract more energy from the ambient air than you've spent on the motor.
callamdelaney 1y ago
It’s not as easy as throwing a sail on top of a boat. Having done a quite a bit of sailing on a yacht, the sail and its supports literally run from the top of the mast to the bottom of the keel. I suspect for any great deal of efficiency gain you’d need a similar system on cargo ships to support the forces generated.

defrost 1y ago

I have a dim recollection of exactly this as a VC proposal likely put to YC in the past 24 months or so. I think the notion was to fit masts to existing container ship and stacks, and I gsve it scant attention as my intuition (I once studied actual civil/mech engineering prior to jumping ship for applied math) suggested masts are better as integral parts of ships rather than bolt on after thoughts. EDIT: Wingsails to reduce cargo ship fuel consumption (April 2023) https://news.ycombinator.com/item?id=35426482 https://news.ycombinator.com/item?id=35426482 I’m Joseph, and along with Arpan and Bailey we are the founders of OutSail Shipping. We’re building a sail the size of a 747 that rolls up into a shipping container. https://outsailshipping.com/ https://outsailshipping.com/ https://www.linkedin.com/company/OutSail-Shipping/ https://www.linkedin.com/company/OutSail-Shipping/ When deployed, it will generate thrust from the wind to reduce the fuel consumption of a cargo ship. An array of these devices will reduce fuel consumption on ships by up to 20%. These sails are easily stowed and removed to cause no interference with cargo operations. Here’s a short video showing our prototype: https://www.youtube.com/watch?v=VUpVqzpym54 https://www.youtube.com/watch?v=VUpVqzpym54 Not quite as I remembered .. kite sails, et al. are a good idea, I'm still a bit torn by the physics of a container deployed boom extension sail and the thrust transmission to the ship. Still, I haven't modeled it, so take my thoughts with a grain of salt. EDIT2: Both links appear dead, so I guess that was a swing and a miss. Still, good to see such ideas pursued. EDIT3: Also related 350 tons of of chocolate and wine arrive on world’s largest cargo sailboat (April 2024) https://news.ycombinator.com/item?id=40022801 https://news.ycombinator.com/item?id=40022801

tengwar2 1y ago
This is an area I have some peripheral involvement with. For retrofitted sails on bulkers, the figure of 10% saving in fuel is the usual one mentioned rather than 20%. However given the long life of ships, there is much more interest in retrofit than in new build. You mention container ships. I haven't seen anything explicit on these, and I think the reason is probably that they cruise much faster than bulkers and tankers, which means the potential savings from sail is smaller. I would have thought 20% optimistic even for a new-build.
- defrost 1y ago
  Retro fit is clearly a preferred path for a new approach given ship life spans and size of existing global transport fleet. My gut objection to the container approach taken above in the first link was existing container locking mechanisms for ships can struggle in severe weather to keep the boxes on the boat .. additional forces from a sail (in good weather) might well mimic the forces that break stacks in bad weather. Your point is well taken, I might suggest that container ships could be segregated into fast and slow cargo and that might help somewhat with total fleet fuel consumption. (pure spitball notion).
  - Maxion 1y ago
    I'm sure there's plenty of businesses out there who'd love to advertise near zero or zero emissions transport for their goods, with the caveat that they have to plan a few more months ahead.
komali2 1y ago
Wasn't the main issue with this that fuel is paid for by cargo ship customers (the container owners), not the shipping company? So the shipping company doesn't want to spend a ton of capital to get a 10% discount to all their customers, and there was no way for thousands of random customers to exert pressure on the shipping company to do so. Basically the economics didn't make sense.
- 1y ago

JeremyNT 1y ago

Rotor[0] retrofits already have been done on full size tankers[1]. This is probably a more reliable and practical solution than traditional sails. 0 https://en.wikipedia.org/wiki/Rotor_ship https://en.wikipedia.org/wiki/Rotor_ship 1 https://en.wikipedia.org/wiki/Maersk_Pelican https://en.wikipedia.org/wiki/Maersk_Pelican

cl3misch 1y ago
But why would you use a motor to spin a rotor instead of a submerged propeller?
- Ekaros 1y ago
  No mechanical linkage. Basically just installing rotor on top of the deck and some electric connections are needed. Much simpler and much less error prone. Plus keeps all the usable space on decks below.
- deleted 1y ago
  [deleted]
- jna_sh 1y ago
  Seems an interesting solution to whales being cut up by ship propellers
- wongarsu 1y ago
  Spinning the rotor allows you to generate more power from the wind than what you would have gotten by putting the same energy into spinning a submerged propeller. From what I understand it's not hugely more efficient, but something like 10-20% fuel savings. Not really equivalent to traditional sails, but also much easier to retrofit and doesn't need additional crew
- speed_spread 1y ago
  For the same reason you use electricity for a compressor in a heat pump. It's a lever. You extract more energy from the ambient air than you've spent on the motor.

callamdelaney 1y ago

It’s not as easy as throwing a sail on top of a boat. Having done a quite a bit of sailing on a yacht, the sail and its supports literally run from the top of the mast to the bottom of the keel. I suspect for any great deal of efficiency gain you’d need a similar system on cargo ships to support the forces generated.