Peter Lynn ARCHIVE
40 years ago I was an engineering student-
Just like all of you now.
But I really just wanted to be an inventor- had so many ideas for things to make.
I had a go at some of these;
In the '70's, a portable sawmilling system that uses just one relatively small diameter circular saw blade- rotating it laterally by 90degrees at the end of each pass thru the log so as to cut out planks. Previous systems had used two blades arranged at 90degrees to each other that cut in one direction only. I made and sold a few of these machines, so as to prove the idea and the market, then licensed the system to a mainstream sawmill equipment making company. Unfortunately, they were the subject of a takeover just after this- an asset's raid type of takeover, and didn't have any focus left over for new portable sawmills.
With expenditure exceeding the royalty income, I abandoned the patent.
In the last 25 years this system has become the world standard- with 10's of thousands of units now having been supplied by various manufacturers, worldwide.
There's a lesson in this, but I expect all of you will have to learn it for yourselves:
Ideas in themselves are worth nothing- it's commercialisation that matters.
Commercialisation is the difficult (and therefore the well rewarded) bit. Most aspiring inventors believe that they just have to think up the idea- then someone else will come along and turn it into money for them.
This doesn't happen- well almost never. You have to do it all yourself if it's to work out.
And then, always having been enamored of Stirling Cycle engines, a next door neighbour's kid (Don Clucas) and I started a Stirling engine development company in the early '80's. After 5 years or so, my doubts about our being able to commercialise the design we were developing caused me to pull back from the project. Don continued on, persuaded outside investors to support him and by last year was looking to be on a path to success.
Lesson number two- NEVER GIVE UP!- except if the idea truly is hopeless- the most difficult judgment of all for an inventor.
During all this though (before actually), I had been seduced by kites.
Particularly by traction kiting- the use of kites to replace sails as a driving force for things.
The history of traction kiting is long; Even 10,000 years ago, the inhabitants of South East Sulawesi had the necessary ingredients. There is a type of large leaf that grows there that will fly well as a kite without modification- and they certainly had fishing line. They also had a reason to develop kite flying; for fishing. Kite fishing from canoes has been a major activity there since before recorded history began. There is no doubt that they were in fact using kites for pulling canoes around- even if as a side effect of flying kites for fishing- a very long time ago: From linguistic and artifactual evidence, Polynesian migrations that started from Sulawesi more than 5000 years ago did carry kites with them. Hawaiian rock drawings and other evidence from there also show kites being used in a purposeful fashion to pull canoes from island to island.
More recently, in the 1820's, George Pocock, a schoolteacher from Bristol in England developed kites for pulling horseless carriages- and boats. He used 4-line controllable kites and was quite capable of sailing upwind, and did- on land and water.
Why then didn't traction kiting take off at this time- why do the overwhelming majority of yachts (water, land and ice) still use sails on masts rather than kites?
Good question.
The reason is that kite control is very difficult.
Except for downwind courses any kite with efficiency (L/D) sufficient to leg it with conventional sails will occasionally accelerate to a speed through the air determined by the relationship L/D x true wind speed- and pull 25 times or more than what the same kite will do while flying at steady state in the same wind.
This either: breaks the kite, the lines, the boat or the flier- or all of these.
The answer is of course to develop some pull mitigation system- commonly called reefing or sheeting.
This is not easy- sure it's possible to rig kites so that the pull can be dumped by reducing the angle of attack to zero- but then the kite becomes uncontrollable, and either crashes or, while the flier is attempting to re-establish control, re-engages with the wind and destroys itself (and/or the flier and everything else).
Instead, fliers just have to learn to handle the over-pull- helped by the meager 25% or so pull mitigation that is the current state of the art.
As a direct result of our failure, as yet, to develop fully de-powerable kites, worldwide, about one kiteboarder dies every 2 weeks.
Now I can hear you saying- but this is an easy problem to solve!- well it's not.
In the last 10 years alone, millions of dollars and 10'000's of hours work by designers experienced in this field haven't found answers- until the last few months maybe- but more about this later.
Anyway, while working away at this very challenging problem; to help pass the time and deal to some of the frustration, I've made some things for kites to pull:
Kite Buggies.
While working on kiteboarding development in the late 1980's, I fitted wheels to a silly boat thing so as to enable development to continue while the lake was frozen- from which serendipitous event, the modern sport of kite buggying emerged- now an international sport with many thousands of enthusiasts. (The British buggy Club alone has more than 5000 members).
KiteCat.
Starting in 1987, I filled the long grass in our back yard with some hundreds of attempts at developing the perfect kite boat. And now I have it I reckon- the KiteCat- a technically successful kite sailing boat- but can it also be commercially successful?
KiteSled.
From the first years of kite buggying, skis have been fitted to buggies in place of wheels for use on ice and snow. Unfortunately, this doesn't work very well.
The reason is that, for steering, the ski's need to be caused to turn out of alignment with each other. In this situation they sweep a much wider path and no longer track straight- which can more than double drag. Short wide ski's work a little better in this respect but have more drag for same area than long narrow skis when running straight. The solution was to make long narrow skis that are made to curve laterally for steering. To enable skis that are wide relative to their depth to curve enough for acceptable turning radii, each ski is made up of multiple longitudinal elements that can slide relative to each other. Developed in the latter part of '04, they work exceptionally well- with 80km/hr, UPWIND!, attained on only the second trial. It's expected that their top speed may be even higher. Their major application is likely to be for journeyers crossing the Arctic, Antarctic, Greenland, and Siberia, because they will be able to carry all their supplies with them on the sled, (adding to its ability to resist the kite pull) rather than having to pull a sled behind as is the current method.
I also continued to develop single line kites- bigger and bigger ones.
Contrary to what might be expected, single line kite design is much more difficult than traction kite design. It's so difficult as to be impossible in any realistic sense. An existing successful single line design can be modified with some expectation of being able to predict the effect of the modifications. I don't see any path to the ability to design a NEW style of single line kite and have it fly as predicted, not even nearly, not ever. There is no mystery as to why this is so:
Single line kites have to pilot themselves- by a complex interplay between weight, inertial and aerodynamic forces - made all the more impossibly complex by the inherent variability of wind, turbulent flow and non-rigid surfaces. Maybe it was Arthur Eddington who said, "When I get to heaven, I have two questions for God; what's the story with Quantum mechanics? And, how does turbulent flow work? I don't expect there's an answer to the second."!
However, I blunder around trying to make new single line kites- and sometimes succeed by accident- a sort of comic relief from serious work, and it's fun work- because with no belief that anything other than endless trial and error can have much effect, there's no distress in failure.
Most recently I've designed, and we've built, 3 very large (world record) single line kites- all of 1000sq.m- to top our earlier Mega Bite (1995) and Mega Ray (1997) which were each only 635sq.m.
But now, back to the main challenge;
For the first time ever, there is now specific evidence (rather than just vague hope) to encourage the belief that we may soon have kites that can be fully controlled for pull AND direction.
Bruno Legaignoux- who developed the LEI style kite (in the 1980's) that has made kiteboarding practical- if still a bit dangerous- has further developed this style to a form now generally called "Bow" kites. These have perhaps 75% de-power, with some residual steering being available even at minimum pull. Bow kites have come onto the market from various manufacturers during the last few months. They are definitely a step in the right direction, and will no doubt be capable of further improvement.
It's like when the Wright Brothers showed the world that heavier-than-air flight is possible. This led within a few years to an explosion of designs which were quite different (and better) than the Wrights' approach. Once something is shown to be possible, solutions become much easier to find. Traction kiting is likely to follow this path. With one solution on the market and successful, designers of other styles of kites (such as ram air inflated 'foils) have an example to follow and a reason to do so (survival). There doesn't seem to be any technical reason why I/they can't succeed.
So, I'm off back to New Zealand to work on this.
As the proverb says; "May you live in interesting times" Right on! - you can never ask for better than that.
Thank you for the opportunity to talk with you all.
Peter Lynn, Buffalo, 11 Sept '05
- In the in fact it hasn't yet been accomplished reefing or (except downwind)with masts
