Comment by trillic | Hacker News Reader

Comment by trillic | Hacker News Reader

Awesome to see this on Hacker News, I love whenever we get sailors on here. I have tons of questions.

Why steel? Durability I assume? Have you modeled using a textile?

Do you have load sensors throughout the wing? Anemometors?

How active is the trimming? Is it just a single axis of rotation or do you have the ability to adjust the leech and luff shape? If so do you have the ability to adjust both the leeward and windward skins? Or just the windward? 2mm steel seems like it has a decent amount of play at that scale? Have you built any bigger scale models with steel? Feels to me like iteration time would take a significant hit playing with steel instead of cloth?

As consistent as these ships are with their speed under motor, the apparent wind will be all over the place. Could see apparent from 50+ on the nose to 5 knots from dead astern. Do you intend to have a fixed set of optimal wind velocities and trim settings? Or want to make something that is usable and automatic in anything but the most violent of breezes?

How much of the bill-of-materials is custom and how much is off-the-shelf type components and structural bits? Any custom composite parts or fairly off the shelf steel tubing, bar, and such?

Also are you hiring?

We're looking at steel partly for durability, but also if we're going to be rolling up the sails a lot then fatigue limits become a lot more important. Cost is key too - I'd love to make this from CF, but price goes way up.

For load sensors, we're thinking strain gauges and pressure sensors to measure wing surface pressure and use that for live feedback. Anemometers might be mounted on the top of the wing, but more likely we'll use a master anemometer at the bridge to send info to the entire array.

For the wing shape, we're currently looking at a symmetric airfoil with fixed ribs inside for strength, so not able to actively change the camber, but we are looking at the ability to do wing warping to change the overall shape of the wing. We are still working to get our first data from on the water, so no good answers on the trim other than we want to make this as automatic and turnkey for the ship master as possible. We're quite early in the design still, though, so don't yet know where the limits of the technology are. Likewise, no answers on BOM and sourcing for you. However, we do plan to start hiring after our seed raise, so feel free to contact us through our website!

+1 to seeing sailing on here :)

I'd imagine the last 1-2 generations of America's Cup boats would have a lot to glean in terms of wing sail camber changes and how they operate. Pretty neat to watch how they use flaps vertically, but there's a lot of hydraulics and carbon at play there as well.

Maybe the competition is these guys? (Inflatable sails) https://www.michelin.com/en/press-releases/michelin-continue...

And something a bit more conventional off the bow when winds are favorable? https://skysails-marine.com/

Skysails seems like it would just be too much for boats to manage. I can't imagine the amount of time you can run that is a large percentage of the trip.

Don't like the potential of the kite going under the boat and getting wrapped up / destroyed in the prop.

MM, yes!

Why can’t you ? Kites and sail usually can operate on the same wind angles, the only limitation I can think for kites are bridges which are not encountered in the large percentage of the trip.

On top of that, higher altitudes wind Jane more power potential than the ones used by sails, ask kytesurfers !

The most recent completed America's Cup uses a boomless dual skinned mainsail held up by a fairly traditional mast. The Cats and Tris between the IACC and the AC75 (2010, 2013, 2017) are more something to take inspiration from I'd think with their more complex internal construction. SailGP's wings, have proven to be quite versatile and durable, albeit with significant maintenance. I'd assume a cargo wingsail would be a bit beefier than a foiling raceboat's.

Despite the switch from wings back to "normal sails" In my view, this latest generation of America's Cup is especially awesome from a follower's perspective for two distinct reasons.

1. The rule is similar to last gen, a foiling 75 foot monohull. A number of the initial engineering work and sorta figuring out how to design and build the various systems has already been done, a team wanting to join in on the fun doesn't have to reinvent the wheel with everything unless they believe they can have an edge by doing so. There are old boats for sale as well as a 40-foot model for training the athletes on their controls.

2. There's a centralized repository for reconnaissance. Meaning, every team, and some of the media have access to sailing, launching, and training footage of every team. What has for over a century required each team employ their own multi-national team of spies to surveil each competitor. It was unnecessarily costly and the fans get the added benefit of being to watch much more of each team's boats as their systems morph throughout the design process. I have a friend on the recon team and as well have been exposed through a yt channel, "Mozzy Sails"[1], who does a great assessment on the various teams systems developments.

If you're a fan of F1 for the engineering bits, you'll likely feel right at home following some of the America's Cup coverage. Even the technical documents like the Class Rule and super interesting to me. [2]

[1] https://www.youtube.com/channel/UCK0h2Yj6jcyeXGeITonYnOA [2] https://www.americascup.com/files/m5498_AC75-Class-Rule-v20....

Small world! I head up the IT systems at Alinghi Red Bull Racing. Agree with your final paragraph that it is extremely close to F1 in terms of engineering bits. Good fun!

Always wanted to say hi.

Didn't Newey get his America Cup fix as part of his contract at Red Bull ?

Unreal, Alinghi's got the claim for the last cup win with an American Skipper and the last win in a "true" monohull. Win it back and get Ed into the IACC again! I know he's itching for it, he still matches J/70s in Tampa Bay and Dragonforce Model Yachts in his backyard.

Hope you the best and any if there's chance you need a hand in Barcelona, I'd drop everything for a shot to work on a campaign.

Look at basalt fiber, similar properties to carbon fiber but much cheaper.

> We're looking at steel partly for durability

...

> For load sensors, we're thinking strain gauges and pressure sensors

"We're looking"? "We're thinking"? Considering your demo video was a guy showing off folded printer paper secured with duct tape, and a gauzy fabric built around an off-the-shelf tape measure....

How far along are you? Sounds like you're nowhere even near a prototype, let alone a beta design. I know every company has gone through a design phase and a (sometimes lengthy) build up... but you don't usually see them start the PR hype train before they've even got a CGI demo or a model that isn't made out of scrap. What is it that makes you a real company, and not just some guy who got real excited about an idea he had last week?

There's a CGI demo on their website.

I'd guess that YC advised them to launch now, maybe to get the idea in front of any people (employees, advisers, customers, etc) who could accelerate the concept.

And YC would be betting that their experience counts for something beyond just a random person with a weekly idea:

"We are hardware engineers with over two decades of experience between us, working at Tesla, SpaceX, JPL, Relativity, and some startups."

Personally, and I know that is outside the SV bubble of experience, I would have expected at least one founder with a solid background as a naval architect and another one with an equally solid background in container shipping.

The experience you listed read more like name-dropping PR to sell this whole thing to other investors down the line.

Or maybe some sailing experience. It didn’t sound to me that they are active sailors.

Will there be a keel or any other foils to help create lift to not just get blown sideways?

To me this seems like solar roofs on electric cars. An obviously good idea that doesn’t really have a meaningful benefit.

And it is not even the first time someone tried.

Container ships don't have keels or other foils like real sailboats do. That wouldn't really be possible due to limited hull space and draft. But the hulls are somewhat resistant to leeway on their own.

The various supplemental sail technologies being tried to improve merchant shipping fuel efficiency are mostly only effective going downwind. They have to make serious design compromises compared to a dedicated sailing rig in order to meet cost and space constraints. But with the cost of fossil fuels expected to continue increasing (eventually including perhaps some sort of carbon tax or emissions cap) even a minor increase in efficiency is worth pursuing.

My guess is that some sort of deployable kite sail will eventually win out instead of this wingsail concept. We'll probably start to see that integrated into new ship designs as the cost is pretty low and the equipment occupies a fairly small volume at the bow.

And when those sails are integrated, which is far from certain, I somehow have my doubts the supplier will be some scrappy start up.

They obviously have nothing except the idea. However, you are being wholly unfair to them expecting a prototype. Even with the entire YC funding they won't be able to build more than a scale model, no chance for a working prototype.

This is a very cool, very hard idea to execute - i shudder to think at the kind of testing, reliability and certification you need to ensure a foldable ten-storey building is safe around human crew in gale force winds. It's a moon shot, and sometimes these take you on the Moon.

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