Former pilot (now paragliders) and founder/engineer here-
I'm not sold that this approach - eliminating the need for coordinated flying- really removes the big barriers to flying. I'm surrounded by aviation lovers who don't fly PPL, and the big barriers are cost, time, and fear.
The Ercoupe tried this exact approach in the 30s in one of the big GA booms and it just wasn't borne out.
I'd love to see more GA pilots, but this won't get us there as quickly as say, comprehensive medical reform or a production aircraft that's cheaper than $50/hr to fly would.
> The Ercoupe tried this exact approach in the 30s in one of the big GA booms and it just wasn't borne out.
The Ercoupe was a great idea for it's time, but we can do so much more with the technology we have today that we didn't have back then
> a production aircraft that's cheaper than $50/hr to fly would.
yes! our long term goal is to get there, but we need more people flying airplanes today to generate enough scale to actually build such an airplane and also stay in business. That's our approach, get more people who can afford to fly doing it, then use that to drive down the cost for everyone.
How many people who don't fly, but can afford to, have you interviewed about their reasons for not flying? This is where I would start trying to solve that problem. I'd be shocked if any of them mention coordinated flying :)
My 2c - the best way to go to big scale with a GA product is to somehow find a way to make it dual use and secure the DoD as a customer. The problem with doing this is that the DoD becomes your main customer and GA becomes your hobby...
We've talked to many and the complexity of flying a plane is a big factor--because the knowledge that if they mess up stick and rudder means they have a high chance of losing control and crashing scares them from flying. Our system helps alleviate that fear.
Containers being out of ISO 668 and weak was a risk that worried me for some time, but it turns out this is a risk for existing owner-operators too! Containers are inspected pretty regularly to make sure they're OK, or so our customers keep assuring me.
With that said, I'd really like to have some sort of load path-sensing autonomy onboard, like strain gauges in the corner posts of our sail which detect an incorrectly fastened or out-of-spec container before the other corners fail. Should be pretty detectably nonlinear if one twistlock isn't installed right and one corner post isn't transmitting any load.
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.
Every "I'm going to start with a shipping container" solution eventually runs into the same problem: shipping containers are effectively empty soda cans. They are only strong when loaded exactly as expected.
Have you actually talked to anyone in the cargo ship industry about your idea?
> Have you actually talked to anyone in the cargo ship industry about your idea?
I worked in the container shipping industry. It doesn't sound like this person ever talked to anyone in the industry. It's not like "add a sail" hasn't been thought off loads of times before. I've seen a few times where people spend 6 months to run a project where they never talked to a person with experience. Then that project would eventually fail. Circumstances and restrictions sometimes change over time, so trying to solve the same thing every few years is a good thing. But "sail in a container", ehh..
Is the sail-container sufficiently heavy to stay in place, or does it need pull on something that's holding it down?
If the sail is pulling, the container below would see a remaining uneven load from above. Is there a limit to this? Loading/unloading an unbalaned container sounds like a problem, but is it, while sitting on the ship?
To me the problem is transmitting the force generated by the sails to the body of the vessel
A small to medium vessel fully loaded is like 150.000 tons. 10% of that is 15000 tons, imagine the force that needs to be transferred to the structure of the ship in a place where it was not designed to handle that force.
Mass of the ship would matter if it was supposed to hover. Trying to google for engine thrust I found numbers that might be in the order of magnitude of 500kN (hp translated to pounds at certain speed). 10% of that through the kite 500kN. That would be enough to lift 50t, which is at the order of magnitude of the maximum mass of a shipping container. Looks like it might work.
The mass is actually 50.000 tons, I typed wrong. My point is not the force to move the mass of the ship, but transmitting that force to the structure of the vessel in order to move it forward. It’s a lot of force, the structure is not made for that
Nonsense. Drinks cans are strong when filled because they are pressurised. Containers aren't pressurised. Their contents have no effect on their strength.
>> 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.
Retraction is pragmatic: Air draft and loading/unloading concerns.
Wings because they perform much better than traditional sails when installed on ships that are already powering forward at speed.
Appreciate the acronym check! That's a great point.
Our design evolved out of a routing/performance analysis software that we run on historical weather data. Angle of attack and trip cost-benefit varies per lane. In general transpacific and transatlantic have amazing winds, with other routes performing well but not at well.
We've done the excel-level analyses on container loads and wing buckling forces. It all checks out. There is a combined-load case at 15deg of roll with heavy containers and heavy winds that's zero-margin, but as you said we can reef when required. Reefing will likely be single-digit minutes, but we can also feather (0 angle of attack) much more quickly.
I'm not sold that this approach - eliminating the need for coordinated flying- really removes the big barriers to flying. I'm surrounded by aviation lovers who don't fly PPL, and the big barriers are cost, time, and fear.
The Ercoupe tried this exact approach in the 30s in one of the big GA booms and it just wasn't borne out.
I'd love to see more GA pilots, but this won't get us there as quickly as say, comprehensive medical reform or a production aircraft that's cheaper than $50/hr to fly would.