5 ms·

I would be cautious about the twisting loads on containers. The side forces will be huge, especially in a swell. Then add mechanical parts that must work in an

I would be cautious about the twisting loads on containers. The side forces will be huge, especially in a swell. Then add mechanical parts that must work in an incredibly hostile environment, and lastly, add on the north Atlantic in the winter, and you are in for a bad time. Ships losing containers due to stacks collapsing happens very frequently, without any extra forces. https://alsum.co/wp-content/uploads/2021/04/Perdida-de-contenedores-en-el-mar.jpg https://alsum.co/wp-content/uploads/2021/04/Perdida-de-conte... Look at a purpose-built sailship from the age of sail in a north Atlantic storm. It is a rough ride. https://www.youtube.com/watch?v=Y7RABaByP_8 https://www.youtube.com/watch?v=Y7RABaByP_8 Another attempt in a similar fashion is the Oceanbird concept by Wallenius Wilhelmsen, but that means building the vessel from the ground to handle the forces and that over-head loading and unloading is not possible, thus the aim at RO-RO ships. https://www.theoceanbird.com/ https://www.theoceanbird.com/ With one vessel already ordered: https://www.walleniuswilhelmsen.com/news-and-insights/highlighted-topics/orcelle https://www.walleniuswilhelmsen.com/news-and-insights/highli... Personally, as a commercial sailor and software engineer, this container approach screams of VCs throwing money at commercial shipping without understanding the industry. Profit margins are non-existent and are already hugely optimized with possibilities for specialized solutions. This wing sail will have to compete with synthetic fuels without increasing the cost due to crewing requirements.

jpm_sd 4y ago
Agreed on all counts. "Mirage" is the perfect name for this product.
- L_226 4y ago
  I'm sure it's implied the container itself will be fixed to the hull to meet those requirements
  - robin_reala 4y ago
    It’s really not: look at the first video on https://www.outsailshipping.com/ https://www.outsailshipping.com/
    - bkor 4y ago
      That video shows that they have no clue about containers or the container shipping industry.
ArpanRau 4y ago
Yep, supporting the moment from the wing via containers is the biggest structural concern. The containers are strong enough in most sea states, with reefing/feathering required in heavier winds and seas. We will stow the sail long before it encounters conditions like the ones shown in your video. Oceanbird is awesome! The trouble is that overhauling the entire industry with new-built ships would take too long to make a meaningful climate impact, and be extremely expensive (not to mention that their approach only works for ro-ros). Synthetic fuels will compete with aviation for the green hydrogen supply (needed to make methanol/ammonia/green hydrocarbons) and are expected to cost 2-3x what current fuels cost. This net makes our fuel cost savings case even stronger. Industry insiders generally already know that there's really no good cost-saving decarbonization solution, and that decarbonizing fast is a hair-on-fire problem for owner/operators. The barriers standing in the way of most wind-assist devices are: poor ROI, shipyard availability for retrofits, risk to shipwoner (capital upfront), and that they don't package on containerships. We solve all these problems by using a large, efficient wing and depending on the container load path. There are technical problems to solve, but the fundamental physics works.
- theflyingpigeon 4y ago
  >> Oceanbird is awesome! The trouble is that overhauling the entire industry with new-built ships would take too long to make a meaningful climate impact, and be extremely expensive (not to mention that their approach only works for ro-ros). Shipping is responsible for like 2% of emissions. A 5-10-20% reduction on a small number of vessels for a small number of voyages is not gonna make a dent.
- julosflb 4y ago
  What is the order of magnitude of the wind load generated on one single wing?
  - ArpanRau 4y ago
    10s of Kn . It's <10% the wingloading of a 747.
- mike_d 4y ago
RhodesianHunter 4y ago
This is clearly intended to supplement, not replace, the ship's existing power source. You would fold these down rather than trying to ride out a swell with them up. They go out of they way to clarify how easily these can be furled and unfurled.
- goosinmouse 4y ago
  Im no engineer but this is what i thought too. Just automatically fold the sails when gusts reach above a certain threshold. Shouldn't be too hard, right?
  - nickff 4y ago
    This may be more challenging than you think; depending on how you 'fold' the sails, you may end up with enough 'windage' 'aloft' to over-stress the connections anyway. They'll likely be forced to bring the wing down completely, which will either make the wings small or expensive.
    - Turskarama 4y ago
      I believe the design is to roll them up like a measuring tape.
  - deleted 4y ago
    [deleted]
roflyear 4y ago
Well, you don't have to run it in those conditions.
- nickff 4y ago
  Most of the popular shipping lanes traverse hostile conditions for at least one season of the year.
carabiner 4y ago
Everyone's forgetting that this is just like a jetliner wing. Huge forces, harsh environments, long lifespan... this is how commercial airplanes are designed, and one of the founders is a professional aerospace engineer who worked at Tesla.
- roflyear 4y ago
  > professional aerospace engineer who worked at Tesla. Being fair, this is really broad and doesn't mean much at all.
- Someone 4y ago
  > Everyone's forgetting that this is just like a jetliner wing. Just like a jetliner wing that can be folded up. On the plus side, jetliners regularly hit speeds relative to the air that are ten times as fast
sourcecodeplz 4y ago
It's never gonna work for a multitude of reasons like you said. Usually I'm not pessimistic but this really seems like: we have an idea, make a video, post it on a site, ask questions later.
- stevage 4y ago
  It probably won't succeed, because most startups don't succeed.
  - leghifla 4y ago
    It won't succeed because of physics/math. They claim a save of 400kW per sail, with a boat cruising at 22kts. Let's do some math: - 400kW is 400e6 J/s, or 400e6 N.m/s - 22kts is 11.31m/s So the forward force must be 400e6/11.31 = 3.5e7N, so around 3500 metric tons of force for a single sail. And with a relative wind coming from the front usually, this means the side force will be much bigger than that. I am calling this BS
    - theflyingpigeon 4y ago
      Exactly my point. Not to mention transferring that load to the body of the vessel, which has a structure made to withstand loads in specific points. A container stacked on top of other containers for sure isn’t able to sustain such forces lol not even if it’s well latched. It’s just too much force. Also the ship is hollow, there are like 5 rows of containers below deck, so the deck itself is not very strong except for some points that have the mechanism for the ropes.

jpm_sd 4y ago

Agreed on all counts. "Mirage" is the perfect name for this product.

L_226 4y ago
I'm sure it's implied the container itself will be fixed to the hull to meet those requirements
- robin_reala 4y ago
  It’s really not: look at the first video on https://www.outsailshipping.com/ https://www.outsailshipping.com/
  - bkor 4y ago
    That video shows that they have no clue about containers or the container shipping industry.

ArpanRau 4y ago

Yep, supporting the moment from the wing via containers is the biggest structural concern. The containers are strong enough in most sea states, with reefing/feathering required in heavier winds and seas. We will stow the sail long before it encounters conditions like the ones shown in your video. Oceanbird is awesome! The trouble is that overhauling the entire industry with new-built ships would take too long to make a meaningful climate impact, and be extremely expensive (not to mention that their approach only works for ro-ros). Synthetic fuels will compete with aviation for the green hydrogen supply (needed to make methanol/ammonia/green hydrocarbons) and are expected to cost 2-3x what current fuels cost. This net makes our fuel cost savings case even stronger. Industry insiders generally already know that there's really no good cost-saving decarbonization solution, and that decarbonizing fast is a hair-on-fire problem for owner/operators. The barriers standing in the way of most wind-assist devices are: poor ROI, shipyard availability for retrofits, risk to shipwoner (capital upfront), and that they don't package on containerships. We solve all these problems by using a large, efficient wing and depending on the container load path. There are technical problems to solve, but the fundamental physics works.

theflyingpigeon 4y ago
>> Oceanbird is awesome! The trouble is that overhauling the entire industry with new-built ships would take too long to make a meaningful climate impact, and be extremely expensive (not to mention that their approach only works for ro-ros). Shipping is responsible for like 2% of emissions. A 5-10-20% reduction on a small number of vessels for a small number of voyages is not gonna make a dent.
julosflb 4y ago
What is the order of magnitude of the wind load generated on one single wing?
- ArpanRau 4y ago
  10s of Kn . It's <10% the wingloading of a 747.
mike_d 4y ago

RhodesianHunter 4y ago

This is clearly intended to supplement, not replace, the ship's existing power source. You would fold these down rather than trying to ride out a swell with them up. They go out of they way to clarify how easily these can be furled and unfurled.

goosinmouse 4y ago
Im no engineer but this is what i thought too. Just automatically fold the sails when gusts reach above a certain threshold. Shouldn't be too hard, right?
- nickff 4y ago
  This may be more challenging than you think; depending on how you 'fold' the sails, you may end up with enough 'windage' 'aloft' to over-stress the connections anyway. They'll likely be forced to bring the wing down completely, which will either make the wings small or expensive.
  - Turskarama 4y ago
    I believe the design is to roll them up like a measuring tape.
- deleted 4y ago
  [deleted]

roflyear 4y ago

Well, you don't have to run it in those conditions.

nickff 4y ago
Most of the popular shipping lanes traverse hostile conditions for at least one season of the year.

carabiner 4y ago

Everyone's forgetting that this is just like a jetliner wing. Huge forces, harsh environments, long lifespan... this is how commercial airplanes are designed, and one of the founders is a professional aerospace engineer who worked at Tesla.

roflyear 4y ago
> professional aerospace engineer who worked at Tesla. Being fair, this is really broad and doesn't mean much at all.
Someone 4y ago
> Everyone's forgetting that this is just like a jetliner wing. Just like a jetliner wing that can be folded up. On the plus side, jetliners regularly hit speeds relative to the air that are ten times as fast

sourcecodeplz 4y ago

It's never gonna work for a multitude of reasons like you said. Usually I'm not pessimistic but this really seems like: we have an idea, make a video, post it on a site, ask questions later.

stevage 4y ago
It probably won't succeed, because most startups don't succeed.
- leghifla 4y ago
  It won't succeed because of physics/math. They claim a save of 400kW per sail, with a boat cruising at 22kts. Let's do some math: - 400kW is 400e6 J/s, or 400e6 N.m/s - 22kts is 11.31m/s So the forward force must be 400e6/11.31 = 3.5e7N, so around 3500 metric tons of force for a single sail. And with a relative wind coming from the front usually, this means the side force will be much bigger than that. I am calling this BS
  - theflyingpigeon 4y ago
    Exactly my point. Not to mention transferring that load to the body of the vessel, which has a structure made to withstand loads in specific points. A container stacked on top of other containers for sure isn’t able to sustain such forces lol not even if it’s well latched. It’s just too much force. Also the ship is hollow, there are like 5 rows of containers below deck, so the deck itself is not very strong except for some points that have the mechanism for the ropes.