Is This the Future for Zero Carbon Footprint Cruising

[David_Old_Jersey]

No.



...

[cat man do]

Originally Posted by hummingway

I wonder at what point the kite becomes a problem. How much wind can it take? You'd need to be able to dump the wind as you reeled it in so I'm guessing they have trap doors?

How do you dump wind from a normal kite?
why wouldn't these be done the same way?

[deckofficer]

Kit Kats, because it is a glass hand laid hull is still too heavy with the 1/3 glass to 2/3 resin and of course not nearly as strong as vacuum bagged 2/3 glass and 1/3 resin. That is probably why you haven't seen much "movement" on the Kit Kat site. Already there are many entries of very strong, light, efficient hulled, power cats in the 35'~43' range, with the lightest at <8000 lbs to the largest but still <15000 lbs. With this combination, even gas guzzling outboards can get a cruise of 17 kt while only consuming 2 liters per nm. Top speed of 35 kt should you feel the need to outrun a front.

[ausaviator]

"Fossil Fuels. Using the past to power the future."

There is no other viable way at present!

[hummingway]

Originally Posted by cat man do

How do you dump wind from a normal kite?
why wouldn't these be done the same way?

What do you mean by normal kite? Normal kites aren't big or attached to the front of a boat. That looks more like a parachute or a parasail and dumping wind can be an issue with a parachute.

[ausaviator]

It would need to be computer controlled like the ones on the big ships. Ever watched a Kite-Surfer or flown a dual string kite? More power from the chute when it's down low and less power when it's up high.

The computer (solar powered I would assume) would need to fly the kite and ensure that it remains stable and upright so as to deliver a relatively constant "pull" depending on the wind conditions. The chute would be winched in when not needed. It may need some human assistance to be launched and packed away again after use.

Simple concept and fantastic idea..... IF.... you are going down-wind, or close to it.

[cat man do]

Originally Posted by deckofficer

Kit Kats, because it is a glass hand laid hull is still too heavy with the 1/3 glass to 2/3 resin and of course not nearly as strong as vacuum bagged 2/3 glass and 1/3 resin.

Disagree
My current and last build (hand laminated) both had considerably lower glass/resin ratios than you 1/3 glass to 2/3 resin claim.
They also had lower glass/resin ratios than some "professionally built" vac bag boats I have seen done.

That is probably why you haven't seen much "movement" on the Kit Kat site. Already there are many entries of very strong, light, efficient hulled, power cats in the 35'~43' range, with the lightest at <8000 lbs to the largest but still <15000 lbs. With this combination, even gas guzzling outboards can get a cruise of 17 kt while only consuming 2 liters per nm. Top speed of 35 kt should you feel the need to outrun a front.

What has anything you mention have to do with kitesails?

[deckofficer]

With this little cat cruiser consuming 1 L per nm @ 17 kts, you are now at a weight (8000 lbs) and hull efficiency that makes electric/solar feasible.
Prowler NZ10.4 Power Catamaran - Specifications

And the Germans have the electric outboard available now.


Two of those each side to replace the gasser clamp-ons.

[cat man do]

Originally Posted by hummingway

What do you mean by normal kite? Normal kites aren't big or attached to the front of a boat. That looks more like a parachute or a parasail and dumping wind can be an issue with a parachute.

Normal kite like a 3 attachment point spinnaker
ease a corner and load is decreased
Dump a corner and load is gone.

Same with a traction kite

[cat man do]

Originally Posted by deckofficer

With this little cat cruiser consuming 1 L per nm @ 17 kts, you are now at a weight (8000 lbs) and hull efficiency that makes electric/solar feasible.


And the Germans have the electric outboard available now.

Two of those each side to replace the gasser clamp-ons.

Small problem
4.5 knots of electric in no way compares to 17 knots of petrol power

[deckofficer]

That was 4.5 kt at only 273 watts. Each motor is capable of 4000 watts cont., (4) could pull 16000 watts / 746 = 21 hp.

http://www.prowler.co.nz/Documents/8...20brochure.pdf

[cat man do]

For how many minutes?

They still have a long way to go yet before being a viable replacement IMHO.

[deckofficer]

Would depend on solar production and battery bank size and of course the speed you want to cruise. My guess, if you can tolerate 6 kt cruise, you could size the panels to meet the energy demands and that was the purpose of the thread, combining light weight, hull efficiency, with perhaps in the future, deployed kite propulsion with the winds within 50 degrees of straight down wind, and hybrid fossil/solar/stored energy propulsion. Simple hybrid would be the gasser clamp-on on one side, twin 4000 watt electrics on the other. Twin engine in harbor vessel handling with your choice of cruising speed and energy type used.

[hummingway]

Originally Posted by cat man do

Normal kite like a 3 attachment point spinnaker
ease a corner and load is decreased
Dump a corner and load is gone.

Same with a traction kite

A spinnaker is a considerably different animal then that. Someone mentioned fighting kites and I can see how it could be done with a something along that line.

[hummingway]

Originally Posted by deckofficer

Would depend on solar production and battery bank size and of course the speed you want to cruise. My guess, if you can tolerate 6 kt cruise, you could size the panels to meet the energy demands and that was the purpose of the thread, combining light weight, hull efficiency, with perhaps in the future, deployed kite propulsion with the winds within 50 degrees of straight down wind, and hybrid fossil/solar/stored energy propulsion. Simple hybrid would be the gasser clamp-on on one side, twin 4000 watt electrics on the other. Twin engine in harbor vessel handling with your choice of cruising speed and energy type used.

Solar and storage solutions are improving rapidly and I think we'll see more craft using it every year.