Kite power

[Jeff F]

I shared this link in another thread and it generated some discussion.

LibertyKite 40m² - LibertyKite

Le LibertyKite 40m2 comprend un kite et un système de lancement et de descente. Il vous permet d'augmenter votre autonomie et votre sécurité.

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I'm contemplating remote coastal cruising, and have been considering various options for backup propulsion for my single engine boat.

This guy looks quite practical, and I'm slowly getting comfortable with the idea of ordering one.

Does anyone have practical advice or experiences? This particular system was designed for sailors as a get-home system in case of rig failure/loss. I'm quite impressed with what I've learned about it.

 

[KnotYet]

If I was thinking about how best to add sail power to my motorboat, I'd start with a mast.
Once I'd firmly mounted a 20'+ mast, I'd buy some used sails. Easier to control than a kite.

The kite in the site (it rhymes!) will run about $10k. Used sailboat masts/rigs are far cheaper.

 

[Mambo42]

I think a kite would be something for far off shore, not in coastal waters with a lot of traffic. I agree with KnotYet that putting a mast on the boat would be the first solution, a kite would be the last option.
On top of that, what is the purpose of the kite ? Is it to extend the range of the boat or is it to reduce fuel cost ?
If it is to reduce fuel cost, then perhaps sticking to a sailing vessel is a better option.
If it is to increase the range of the vessel, why not buy a motor sailer immediately ?

 

[Bmarler]

Agree. A mast can be used to fly an asymmetrical spinnaker, much easier to manage.

 

[Fletcher500]

Parlay Revival (YT channel) had an episode on a kite powering a 45 ft Cat a few months ago. It didn't go all that well from what I could tell.

 

[Don L]

I wonder how the cost of the sail plus the needed reinforced anchoring points to the boat compare to better tow insurance for the planned cruising grounds.

 

[Jeff F]

I wonder how the cost of the sail plus the needed reinforced anchoring points to the boat compare to better tow insurance for the planned cruising grounds.

There is no towing insurance or private service for my planned cruising grounds.

This sail is about $8k and requires no special hardware to deploy.

I don't see a mast as being suitable due to stability concerns. You can't just hang that much sail on a mast without ballast/stability concerns. The kite applies all forces at the deck level.

 

[boomerang]

Admittedly I haven't researched too deeply into get-home kites but I watched the demonstration videos in the link attached and the first thing I noticed was how docile the sea conditions were. It would be more of a sales pitch if there was a demo in more usual (translation; rougher) conditions.

 

[KnotYet]

There is no towing insurance or private service for my planned cruising grounds.

This sail is about $8k and requires no special hardware to deploy.

I don't see a mast as being suitable due to stability concerns. You can't just hang that much sail on a mast without ballast/stability concerns. The kite applies all forces at the deck level.

This is your thread and you seem to have made up your mind but you did ask for advice.
A boat with no flybridge like yours could mount a 20' stick and fly 400 sq. ft. of sail for use
in downwind sailing (like the kite does) with little effect on stability for less $ and effort, IMO.
The mast could be in a tabernacle and stowed when you didn't want or need to use it.

 

[DDW]

Certainly if you get one, try it in conditions that you would expect to use it, before you need to use it. The demo video of parachute sea anchors is similar, makes it look fairly easy to deploy and retrieve, but in practice may not be. You'd also get a feel for speed achieved and flexibility of course.

 

[Jeff F]

Certainly if you get one, try it in conditions that you would expect to use it, before you need to use it. The demo video of parachute sea anchors is similar, makes it look fairly easy to deploy and retrieve, but in practice may not be. You'd also get a feel for speed achieved and flexibility of course.

Deployment and retrieval is the big challenge, I suspect. I've scoped out a couple of systems. This design tries to address these concerns.

I could imagine motorsailing regularly with a rig like this. It could well cut fuel consumption in half when conditions are favourable.

A boat with no flybridge like yours could mount a 20' stick and fly 400 sq. ft. of sail for use
in downwind sailing (like the kite does) with little effect on stability for less $ and effort, IMO.
The mast could be in a tabernacle and stowed when you didn't want or need to use it.

I have friends who have pointed that out. I have a mast on a tabernacle now that could easily carry one or two small sails. But the base of the mast is 12 ft above the WL.

I really don't think I can safely fly 400 sf from that level, and trim adjustments from the PH are impractical for a conventional downwind sail.

It seems like a sub optimal solution, which led me to look at more innovative products.

 

[mvweebles]

Willard 36 was originally a sedan model (Weebles is a sedan - sistership shown). Sometime in the late 1960s, Blaine Seeley drew a pilothouse version with a forward mast (second picture). It was this version that went to Hawaii in 1987. No information on how it returned, a more challenging trip.

Weebles originally had a slightly taller mast than shown in the attached. She had a twin headsail arrangement that was never flown. I removed the mast so I could have a full length hard top for the tropical - a good decision for our use.

If I ever wanted to cross an ocean with Weebles (which I don't), I'd want some sort of sail assist and get-somewhere propulsion. I'd certainly engage a naval architect (Tad Roberts has toyed with adaptations to a W36). My question would be instead of a single stayed mast, maybe a wishbone A-Frame anchored to the caprails instead of a central mast. Likely a very large headsail instead of a main.

The kite seems interesting but my hunch is it works better on paper.

Peter

 

[KnotYet]

The downside of flying a kite is, IMO, that it is only 1 size. All or nothing for a premium price.
Even a modest mast can fly similar sq. ft. of sails but can reduce or add to them for less $$.