Pulling a kayak???

[Buffomarinus]

Just curious...

I've got an old B line two person glass kayak with a built in rudder. Anybody have any suggestions for combining this with my 3.0 Sam2? In order to get a foil to pull this rig, would it be necessary to fit a keel or sideboard to keep from being pulled sideways? I thought it might be possible to put the kite pilot up front with another bod in the back cockpit working the rudder. Anybody else try this?

[BobM]

Try the info on the floowing link (about half way down the page)

http://www.amoka.com/kayak.html

Cheers

BobM

[Buffomarinus]

BobM,

Thanks for the URL. It's exactly the sort of info I was looking for.

Rob.

[Cranky Franky]

BM,

can you let me know how this works out? I am a sea kayaker and a sail at present but have always been facinated with the idea od using a kite with a kayak. I have only seen it done on the net and have not met anyone who uses a kite to pwer a kayak. Would love to try it.

[Michael W]

Hi guys

I'm very interested in this too. I'm about to build a rig that, according to my computer simulations and my .45m model (my wife unkindly calls my bath pull along toy) should work.

You might be interested in stuff from Peter Lynne

http://www.peterlynnkites.com/images/sailing/PLboats/

and

http://peterlynnhimself.com/Kites_For_Yachts.php

Still a lot of issues but should know before the year is out, if my rig works.

Cheers

Mike

[jdhot]

Hi Guys,

I'm interested in this myself, so I'm curious to know how you all go

The only thing you my want to consider is a water kite, for if you hit the water

your normal foils tends to want to become a sea anchor

cheers

JD

[Crooked]

It'd be interesting to see how this might work out.

There would certainly be the risk of being pulled out, or over if you get the kite in the wrong place, much like a buggy I suppose. I just wonder if a sail might be a better option......not as much of a challenge though!

What do you usually do with the Sami Bufo? I have a 5 m and a few other kites that I use for buggy runs at Mission Beach, if your ever on the coast maybe we could meet up at a location.

cheers

[dafunk]

hi all, i have a inflatable 5m kite and a inflatable kayak , its made from pvc and i just repaired it using plumbers pipe glue ! have tested kayak in the pool and so far all good . i hope to try it this weekend .

going upwind should be okay as you sit in it and steer with your torso . mine has 2 small fins ,front and back. in a powered up situation it will slide to much i think . i could increase fin area but because its pvc the current fins flex there mounts heaps. a fiberglass one would be better ,then larger , solid fins could be mounted to give more up wind drive .

i will just try in lightest wind possible bout 10 knots . it will be juggling act as light wind is not good for water launching kite? then in stronger winds i'll go down wind . should be fun though just hope i dont get wet its to cold ! i only got kayak to learn kiteboarding and have also just bought mountainboard !! loving it!!

[nigel]

Dafunk: Yes a keel is going to be the biggest issue.

Your going to need to resist the pull of the kite, and also get the pull point as low as possible.

Any kite pull to the side could easily result in you being pulled out, make sure you have a way of relauncing the kite, and getting back into your kayak should you need to.

And wear a life jacket too.

See here for some uber crazy boaters: http://www.kiteboat.com/

Crooked: A sail needs a mast, not easy to put on a kayak.

Your also limited by the size sail you can put up, no such restrictions with a kite.

[Crooked]

Aha yes your right Nigel, didn't really think too far. I just remember one of my mates who soes some ocean kayaking saying that he sometimes uses a sail but I guess the sea kayaks are designed to take them.

Probably too closely resembles a blowkart on the water with a sail anyway.....don't tell Peter I mentioned blowkarts

[Michael W]

Thanks guys. All interesting points. Yes water relaunch is an issue. Again my computer simulations indicate that flyover propensity is related to kite weight which is greater in inflatable and structured kites. Unfortunately I don't think you can paddle fast enough to overcome this if the wind dies almost completely(???) Your experience might help here. My rig allows for reeling the kite in while paddling but this would change the dynamics of the kite and possibly still end up with loss of control and the kite in the drink. Not sure of the answer yet but it relies on an appropriate design which does not result in an enormous sea anchor caught in waves off a cliff face dragging you to imminent destruction.

Paddling upwind during lulls while using a smaller kite or just using a huge kite, very efficient hull and sailing cross wind does, however, in my simulations result in a significant reduction in the kite ending up in the water. The benefits of an appropriate kayak hull (and paddling) here over kite boards is that they are efficient at lower speeds and you don't need to generate enough power to get them on the plane. A good crosswind (or slightly upwind) boat speed coupled with a little wind generate enough apparent wind to keep the kite from reaching it's flight failure threshold (stall, loss of control, flyover, deflation etc.)

With a kayak hull you may, however, need to get back in after being capsized by a large wave with a suddenly very large traction kite pulling you along at very efficient high speed and which you don't want to fly into the drink because of the afore mentioned giant sea anchor effect. So yes, recovery is a big issue.

In a nutshell benefits of kites over sail are the obvious increased power from the increased wind speed at altitude but also the better apparent wind direction resulting from this. According to Wikipedia paragliders can have a lift to drag of up to 12 (although I understand most traction kites are closer to 5). If a kite can be made with a lift to drag close to a normal sail, even allowing for the significant effect of line sag, the increase in power and better apparent wind direction coupled with a narrow, efficient hull, could result in significantly better upwind performance to sailboats. Kites already have the advantage in crosswind and (if there is enough wind and you've got a big enough kite or want to windmill) downwind.

Also rigging masts is a drag.

The main disadvantages of a kite are that the rig and boat have to cope with a huge variation in kite pull and direction and of course, the kite can potentially fall out of the sky.

All just theories so far though as I have zero experience with big kites so any chance to get some experience and take some measurements in real conditions would be appreciated.

[dafunk]

nigel the link was a great read , 30m kite huge ! big names in the canoes .didnt get to try mine this weekend . cheers

[Michael W]

Nice link Nigel. This explains how the Hawaiians ended up in New Zealand.

Dafunk (I hope you appreciate how hard it is for me to call someone that) So how, Defunk, did it go? I have been waiting to hear. I guess you already know the lift on your fins has to be roughly equal to the pull from the kite to go up wind. So if you can't step on them without them flexing too much you may have a problem.

If you're around Sydney and want a hand or some moral support or someone in a tinnie with a 15HP eggbeater and some life jackets, let me know.

Regards

Mike

[Steve]

Thanks guys. All interesting points. Yes water relaunch is an issue. Again my computer simulations indicate that flyover propensity is related to kite weight which is greater in inflatable and structured kites.

I'm totally unaware of what modelling simulator you are using, however modern kite design and kite designers take overflying as a negative trait in all kites. The tendency to overflying is hardly related to weight at all, however it is strongly related to tow points, angle of attack or AOA and Centre of Effort or COE.

Even an unbalanced wing can be bridled or built to be very stable, and only in a complete lull or gust then lull situation would the kite be induced into an overfly and luff situation.

Unfortunately I don't think you can paddle fast enough to overcome this if the wind dies almost completely(???) Your experience might help here.

Correct, there will always be situations, where the kite will end up in the water, and there would be nothing the kayaker could do to prevent that.

My rig allows for reeling the kite in while paddling but this would change the dynamics of the kite and possibly still end up with loss of control and the kite in the drink. Not sure of the answer yet but it relies on an appropriate design which does not result in an enormous sea anchor caught in waves off a cliff face dragging you to imminent destruction.

Paddling upwind during lulls while using a smaller kite or just using a huge kite, very efficient hull and sailing cross wind does, however, in my simulations result in a significant reduction in the kite ending up in the water. The benefits of an appropriate kayak hull (and paddling) here over kite boards is that they are efficient at lower speeds and you don't need to generate enough power to get them on the plane. A good crosswind (or slightly upwind) boat speed coupled with a little wind generate enough apparent wind to keep the kite from reaching it's flight failure threshold (stall, loss of control, flyover, deflation etc.)

If you have designed a steerable dual or multi control line kite, then you will immediately experience problems with roll, unless you have outriggers and even then you will experience issues with pitch, once you start to engage more power to get more speed and upwind angles, etc.

Peter Lynn has done more experimentation that anyone that I'm aware of, regarding kite sailing and he has experimented with a large variety of hulls and boat designs, settling lately for a rigid monohull design that gave the best upwind and speed. However for vesatility and easy use over a wide range of water surfaces the Kite Kat is what works and sells for the company, one of these Kite Kats is available for demo at Kitepower Brisbane.

They work best with the Peter Lynn Arc style kites, due to the inbuilt tendency of these kites to "auto zenith". Auto Zenith allows for the kite pilot to let go of the control bar and walk the boat into the water and if the kiter hets out of shape on the water, then the control bar can be released and the kite will stabilise and self steer up to the zenith, vertically above the Kite Kat, with no input from the kite pilot. These kites can be relaunched from the water. http://www.peterlynnkites.com/vehicles/boats/boats.htm

However it is good kite design, rigging and pilot input that prevents a kite from stalling, flyover or luffing is a kite design thing, and deflation is either mechanical or due to no wind.

With a kayak hull you may, however, need to get back in after being capsized by a large wave with a suddenly very large traction kite pulling you along at very efficient high speed and which you don't want to fly into the drink because of the afore mentioned giant sea anchor effect. So yes, recovery is a big issue.

Yes that a very big issue, because your life will be in danger and if you were exited from your craft other people and property downwind of you will be in danger too.

The Peter Lynn arc kites have a lot going for them in this respect, however the need serious power kite skills, quality rigging and a large open body of water ot operate in, safely.

There is another style of kite sailing in kayaks, utilising single line design kites. The best known and the best design is the Kayakite, my last post was deleted when I mentioned this kite and posted a link to its details on my website, hopefully mods will not be so harsh this time around, and I'll leave off the link too, however its in the Single Line category.

In a nutshell benefits of kites over sail are the obvious increased power from the increased wind speed at altitude but also the better apparent wind direction resulting from this. According to Wikipedia paragliders can have a lift to drag of up to 12 (although I understand most traction kites are closer to 5). If a kite can be made with a lift to drag close to a normal sail, even allowing for the significant effect of line sag, the increase in power and better apparent wind direction coupled with a narrow, efficient hull, could result in significantly better upwind performance to sailboats. Kites already have the advantage in crosswind and (if there is enough wind and you've got a big enough kite or want to windmill) downwind.

Also rigging masts is a drag.

The main disadvantages of a kite are that the rig and boat have to cope with a huge variation in kite pull and direction and of course, the kite can potentially fall out of the sky.

All just theories so far though as I have zero experience with big kites so any chance to get some experience and take some measurements in real conditions would be appreciated.

The problem with making higher lift, less drag kites is that you get into issues with stability and massive spikes in downwind pulling power, simply because drag and lift are intricately connected.

Getting kites to have decent wind range, and not become a downwind killing machine, is what modern kite surfing kite designers are getting closer and closer to perfecting.

[Michael W]

Hi Steve

Nice to have some intelligent comment but waayy negative. I would not have mentioned it except I think I've overcome most of the issues you have raised. Time will tell.

The modelling is my own so you may well criticize it but it is a well known fact that heavier planes and gliders have a higher best glide angle speed than lighter ones. There is also more momentum, albeit small, in a heavier kite. So the propensity to overfly is increased. It goes without saying that the bridle positioning on a kite is a critical issue and this is where experience and experimentation are of huge importance but I maintain that, all else being equal, a heavier kite is going to overfly before a light one. Also the AOA can basically be adjusted by the brake lines so this is not an issue. To my limited knowledge the new HQ NEO looks like it could be the way to go.

I have read a lot of Peter Lynne's excellent information on-line and have learned a huge amount from the his writings and the mistakes others have made (perils of the bleeding edge). I was actually considering buying his cat at one time but at the end of the day it's not what I want. You can only kite sail some of the time and if you are caught without wind a long way from home on his cat you are stuffed. Care to swim back to shore towing a boat and kite or try paddling it? What do you do with the kite while you are trying to get back? Where do you keep your paddle? (no smart remarks please) Peter admits most of this himself and talked about putting a motor on it.

Having said that Peter's cat is one solution and does largely solve the pitching, flying and tipping over issues. I would like to try one. Anywhere around Sydney where I can?

Yes you are right about higher aspect ratio etc. etc. and these are all issues when selecting an appropriate kite (or more likely kites). I am aware (theoretically) of the higher wing loadings and the negative effects associated with increased wind speed and manoeuvring the kite but again, less parasitic drag should be a benefit here and it has little to do with AR. Hopefully any reasonably good kite will not become unsteerable in any forseeable conditions (I hope). Please elaborate if you know of any. It would be nice to have a kite that automatically detects that a dangerous situation has arisen and slips into a near zero drag,near zero lift configuration and then pops back when all is well. Maybe one day. Not very good for performing tricks of course.

I'm not interested in simple downwind sailing, however, with a single line kite. What I want is a single person boat that can surf, sail (both upwind and down), quiet water paddle, get me to where I want to go, doesn't need to be launched from a beach, can perform at least as well as a normal sail boat, is not too complicated to sail, is not too expensive, doesn't pollute or wreck the environment, is easy and quick to launch and is not going to kill me. Is this too much to ask? You seem to be saying it is. I sincerely hope you are wrong but maybe I should just give up and buy a Hobie Bravo or a Laser dinghy or maybe a jet ski and forget the wind altogether.

Cheers

Mike

[Steve]

Hi Steve

Nice to have some intelligent comment but waayy negative. I would not have mentioned it except I think I've overcome most of the issues you have raised. Time will tell.

The modelling is my own so you may well criticize it but it is a well known fact that heavier planes and gliders have a higher best glide angle speed than lighter ones. There is also more momentum, albeit small, in a heavier kite. So the propensity to overfly is increased. It goes without saying that the bridle positioning on a kite is a critical issue and this is where experience and experimentation are of huge importance but I maintain that, all else being equal, a heavier kite is going to overfly before a light one. Also the AOA can basically be adjusted by the brake lines so this is not an issue. To my limited knowledge the new HQ NEO looks like it could be the way to go.

Not sure why you think I'm being negative? I'm not ok, in fact I'm positive I'm not

You are confusing aeroplane physics and wind design, with kite design from what I can see. I'm no engineer, or phycics scientist, however I have flown a lot of kites a lot, thats where my understanding comes from, not theory as such just observation and experience.

AOA cannot be changed by a soft foil kites brake lines, however a kite like the HQ neo which I think has a profile adjusting front bridle, can change AOA of the aerofoil to some degree.

It is also a well know fact with anything that flies, that weight is bad, agreed?

There will be an optimum weight for any given wing design, and that has been discovered, both for wings and kites.

Aeroplanes do not get new wing aerofoil shapes every 12 months, like our crazy cosumer driven kites do.

I have read a lot of Peter Lynne's excellent information on-line and have learned a huge amount from the his writings and the mistakes others have made (perils of the bleeding edge). I was actually considering buying his cat at one time but at the end of the day it's not what I want. You can only kite sail some of the time and if you are caught without wind a long way from home on his cat you are stuffed. Care to swim back to shore towing a boat and kite or try paddling it? What do you do with the kite while you are trying to get back? Where do you keep your paddle? (no smart remarks please) Peter admits most of this himself and talked about putting a motor on it.

Yep the obvious solution is to put a small motor on it, however Peter has not wanted to but has talked about the possibility so he is being sensible about it in my opinion.

Having said that Peter's cat is one solution and does largely solve the pitching, flying and tipping over issues. I would like to try one. Anywhere around Sydney where I can?

Yes you are right about higher aspect ratio etc. etc. and these are all issues when selecting an appropriate kite (or more likely kites). I am aware (theoretically) of the higher wing loadings and the negative effects associated with increased wind speed and manoeuvring the kite but again, less parasitic drag should be a benefit here and it has little to do with AR. Hopefully any reasonably good kite will not become unsteerable in any forseeable conditions (I hope). Please elaborate if you know of any. It would be nice to have a kite that automatically detects that a dangerous situation has arisen and slips into a near zero drag,near zero lift configuration and then pops back when all is well. Maybe one day. Not very good for performing tricks of course.

I'm not interested in simple downwind sailing, however, with a single line kite. What I want is a single person boat that can surf, sail (both upwind and down), quiet water paddle, get me to where I want to go, doesn't need to be launched from a beach, can perform at least as well as a normal sail boat, is not too complicated to sail, is not too expensive, doesn't pollute or wreck the environment, is easy and quick to launch and is not going to kill me. Is this too much to ask? You seem to be saying it is. I sincerely hope you are wrong but maybe I should just give up and buy a Hobie Bravo or a Laser dinghy or maybe a jet ski and forget the wind altogether.

Cheers

Mike

No Mike I'm not saying give up, if you knew me you would know that’s not a prt of my vocabulary. Possibly you are asking for too much, certainly you are asking for too much from the current technology available, however if you could compromise on some of your needs a bit, then I think a kite kat may just prove to be a viable and enjoyable option for you.

My business does not own a kite kat yet, I could easily get access to a hobie without sails, and these do make an excellent kite boat. I have a new RIB soon to be delivered, a design that is very seaworthy and its my intention to make it available for projects like yours, as I am keen to explore kite kat sailing myself. The reasons I have not done so before now are to do with time and money, however my circumstances are changing and I want to explore kite sailing more now.

I may be able to get hold of a kite kat to test here in Sydney, I'll make some enquiries.

Many kites used for kitesurfing and traction, do in fact become "practically" unsteerable when overpowered by suddenly increased wind conditions and high AR examples would be the worst.

A wing, let alone a kite (which inherently has more drag than any wing) cannot have near zero drag and at the same time also near zero lift, can it?

That’s just asking for something that would defy known laws of pysics, isn't it?]

This is a great article http://en.wikipedia.org/wiki/Lift_coefficient

So is this

http://home.swipnet.se/ansar/measure.html

And this

http://www.chevron.tug.com/tech.html

Cya and

Goodwinds

Steve McCormack

[Michael W]

Steve

Yeah. Zero lift is possible, but not zero drag.

There seems to be two schools of thought on steering kites. I thought high wing loading kites such as paragliders and traction kites used drag induced steering. Maybe someone can clarify. Aileron style steering with cross bridles I thought was more likely to succeed in low lift coefficient situations. Ie. with little AOA. I can imagine aileron (or lift?) steering on a kite quickly becoming unmanageable and not working or working in reverse when too much load is put on and the kite is stalled. Simply moving the CE of the bridle sideways, of course, should steer a kite like moving your weight on a hang glider but probably not enough for a quick turn or to overcome the increased drag. Whatever the case, kite control in strong winds is an issue. I actually think we're in agreement about high AR kites anyway.

And all of that is academic and a little off topic. I reckon all you really need is a kite that is at least 50% depowerable if you want to go upwind safely. Is that achievable while flying a NEO I wonder. The more depowerable a kite is the less margin you have to cover in your boat design (less weight) and the bigger kite you can carry and the faster you can go ... but these are the issues that must be covered in buggy kiting already but perhaps not as important there.

I don't actually believe a catamaran is a good option. High performance cats work best when flying a hull. Not something you are likely to do with a kite. So performance wise you are starting behind the eight ball compared to a standard sail boat. Also with a catamaran, especially one designed for a mast, you have all the weight of the structure joining the two hulls plus, for any given displacement you have more surface area on the two hulls, two rudders etc. so more weight again and more power required (and more dollars). The standard approach so far is to simply increase the kite size to overcome this. All well and good but this increases all of the other issues with using a kite. Peter Lynne has overcome some of this by giving his cat hulls planing characteristics. A good design but I really think a specifically designed monohull kite boat is what is called for. Something not quite as minimalist as a kite board. A kayak perhaps?

Thanks for the links. I read these some time ago.

Cheers

Mike

[Steve]

Steve

Yeah. Zero lift is possible, but not zero drag.

In a vacuum both are possible, however i thought we were talking about wings in use, not achored to the ground in a shed or something like the lift generated by a house brick?

There seems to be two schools of thought on steering kites. I thought high wing loading kites such as paragliders and traction kites used drag induced steering. Maybe someone can clarify. Aileron style steering with cross bridles I thought was more likely to succeed in low lift coefficient situations. Ie. with little AOA. I can imagine aileron (or lift?) steering on a kite quickly becoming unmanageable and not working or working in reverse when too much load is put on and the kite is stalled. Simply moving the CE of the bridle sideways, of course, should steer a kite like moving your weight on a hang glider but probably not enough for a quick turn or to overcome the increased drag. Whatever the case, kite control in strong winds is an issue. I actually think we're in agreement about high AR kites anyway.

A paraglider is not a kite and when you lump the two together in a sentence it creates confusion around your understanding of kites (paragliders too )

Steerable kites turn by a combination of deflection and wing warping. Kites are quite low lift generating compared to wings moving at much faster speeds, aileron steering does not work on kites, practically. Moving a bridle sideways to alter COE sounds simple, however its probably not such a simple thing to do in practice.

The bug in the reply window is about to bite making it hard to reply from my TV monitor. Why even bother with a Neo, the original design, the Peter Lynn, in its latest variants will do all of that and its a very well proven and reliable design, with auto zenith.

A catamaran is a great design bed to start with, they are cheap, have plenty of room, can take a motor and fuel, and can easily be rigged for a kite propulsion system. They will not win races maybe, and may not point upwind as well as a mono, however they do fit most of your stated needs and could be rigged to lift a hull if you wished (but have you experienced a pitchpole event on a cat flying on one hull with a mast??). Being practical though and fitting most of your stated needs, a hobie 12-14 footer is not that heavy especially when the mast and all the rigging is stripped away, and they almost always come with a trailer, a very practical accessory.

And all of that is academic and a little off topic. I reckon all you really need is a kite that is at least 50% depowerable if you want to go upwind safely. Is that achievable while flying a NEO I wonder. The more depowerable a kite is the less margin you have to cover in your boat design (less weight) and the bigger kite you can carry and the faster you can go ... but these are the issues that must be covered in buggy kiting already but perhaps not as important there.

I don't actually believe a catamaran is a good option. High performance cats work best when flying a hull. Not something you are likely to do with a kite. So performance wise you are starting behind the eight ball compared to a standard sail boat. Also with a catamaran, especially one designed for a mast, you have all the weight of the structure joining the two hulls plus, for any given displacement you have more surface area on the two hulls, two rudders etc. so more weight again and more power required (and more dollars). The standard approach so far is to simply increase the kite size to overcome this. All well and good but this increases all of the other issues with using a kite. Peter Lynne has overcome some of this by giving his cat hulls planing characteristics. A good design but I really think a specifically designed monohull kite boat is what is called for. Something not quite as minimalist as a kite board. A kayak perhaps?

Thanks for the links. I read these some time ago.

Cheers

Mike

OK I'm typing blind now talk to Peter Lynn about buying one of his monohulls designs, then work out how practical it is to transport I think the latest version is about 10M long or something!!!

Remember a kite is not an aeroplane wing or a paraglider, it is a tethered flying device that works at low air speeds and has a poor LD compared to aircraft wings.

Cya and

Goodwinds

Steve

[Michael W]

Whoa 10m. That's 33ft. How many berths does it have? What size kite are you planning to use on that?

Better make sure all the crockery in the galley is well secured in case it decides to take to the air.

I suggest you keep the head closed too.

How many Hawaiians are you planning to use to balance it?

[Steve]

I really have no idea on the actual dimensions, its very long and very narrow. Not a comfy or practical craft at all IMO, but it gave Peter his best performance and thats all he was really interested in.

here's a pic of Jon from KP Qld from a session last night in approx 10 - 12 knots, 15M Cab Convert, he's moving along nicely, with a very depowerable, easy relaunching, safe LEI kite.

Cya and

Goodwinds

Steve

[lickedysplit_au]

Good to see Jon working so hard!! lolz

Would be awsome to see a kitecat like that wizzing around the bay ;) Steve

[dafunk]

hey all , been a bit busy for a bit , still a couple of weeks before kiting again.

anyway now ive got me mountain board yippee ki aye mfs.

will still try the kayak just for fun . not to set any records ha ha .

worst of all i havnt progressed any . its been too long and windy!! enough for newbi

[Michael W]

Yes jon does look very relaxed. Just needs a pina colada in hand.

Steve, How wide are the hulls? I'll do some calcs to see if my kayak has any chance of beating it.

Mike