March 2001

Newsletter, March '01.

Mega-Ray; a retrospective whoops.

A couple of weeks ago, Mark Abernathy. and I noticed some tight bridles in the centre nose area of the Mega-Ray while it was flying at the Pasir Gudang (Malaysia) festival. In the middle of the cats cradle of lines around the mouth area they were hard to spot (that's our excuse anyway) and it took more than one try to grab the offending ones.  Letting them out 2m or so has improved the launching and flying enormously, the violent nose over oscillations that we thought were a necessary characteristic of this kite are now gone, probably the first known metamorphoses of an angry fish into a pussy cat! 

This mis-bridling goes back some years.

Therefore, the infamous Sardinia incident when it tried to kill off most of the German "No Limits" team and then trashed a beach restaurant (usually their job) in one such series of nose over oscillations was not only inexcusably bad flying (by me) but also a mis-rigged kite (you guessed it, my responsibility again). Definitely whoops!

My new kiteboat is on the water at last -(it was going to be launched last November).

The hold up was partly kite distractions but mainly indecision about whether kites are now good enough to enable remote flying.  The choice is either to have the kite attached directly to the boat with the flier controlling it via pulleys and things or to have the kite attached directly to the flier, and then via harness' and things to the boat.  Remote flying is safer because the flier isn't laced around with highly loaded lines, but remote flying causes loss of sensitivity which in itself can be a safety problem. 

For largish kiteboats like this one (weighing around 150kgm plus one or two crew and capable of resisting at least 500kgms of side load when moving) line loads are far more than can be directly resisted by bodily strength.  Even in light winds, pull can momentarily peak at two or three hundred kilograms during apparent wind surges.

I've been caught between irresistible kite pull and immovable objects a few times and these are not my favourite kite flying memories, reminded as I am of them daily by various scars and blurred vision every time I turn my head to the left*-

You've guessed it again, after exhaustive analysis of all the relevant technical kite performance data it became clear that kites do now behave well enough to allow remote rigging.

Not that testicularity doesn't still have a part to play.

On the contrary.  Feet are fully engaged operating the rudders, arms and hands busy operating the kite, (and making value laden gestures to other water users), apparently leaving no body appendages spare for operating the emergency kite release.

But, by innovative central placement of the relevant lever at the front edge of the seat, in your average life threatening emergency the release lever is now automatically crotch operated as the flier involuntarily lurches forward.

Well, this is the theory anyway, for safety's sake this safety feature has been temporarily disabled so that the operator isn't.  Needs more thorough testing- volunteers?!

For the technically minded, if there is anyone at all left in the world who is interested in kitesailing rather than kitesurfing:

Type:  Planing catamaran.

Length overall:  6m

Width overall:  2.5m (trailerable).

Hull Construction:  Glass/carbon/epoxy over polystyrene foam.

Frame: stainless steel tube, lattice structure semicircular traveler.

Rudders: Two at rear, two forward, all linked for steering.

Fliers seat: On a swinging arm always facing the kite and with foot operated rudder bar.

Crew seat: Plenty of space but nothing dedicated yet, (it's too much fun making them fall off)

Overpower Stability: Kite overpower causes downwind hull to lift:- complete auto stability.

Wave Stability: 2m(crest to trough) breaking waves are usually manageable.

Kite Type: anything you like but about 2 sizes bigger than for kitesurfing in the same wind.

Performance:. Only two days on the water (one in flat water one in lumpy surf) and haven't pushed it yet, but so far it's behaving perfectly:  Balanced and very responsive, stable in breaking waves, even side on, and excellent upwind.  Even under powered as we have been, speed is good.  The transition between displacement and planing modes is completely unnoticeable.

For kite launching there are a number of choices.

Currently it is rigged so that one person (the flier) can easily rig and de-rig the kite to the boat, while the kite is flying, providing it isn't pulling more than 60kgms or so.  This enables on shore kite launching/landing in the kitesurfing tradition.  

Now that we want more kite pull so we can try a fully powered up run or two, we will either use more than one person for kite launching and attaching or rig the kite to the boat before launching.

Kites are much better behaved now with >2/1 power control to smooth the surges but full length launches with the kite attached to the boat used to be violent events in the '80's, even for spectators!  For the first few seconds, the boat, crew (and any helpers who forget to let go) were launched into a heart stopping 3g ballistic trajectory, hoping nothing breaks and that the first landing is approximately horizontal. 

Within a few weeks we'll go to "motor launching"  With a (very) small outboard motor it is possible to set a suitable kite onto the water and motor back upwind until it launches.  I haven't tried it with this boat yet but have tested it previously and can recommend it as the safest and most reliable kite launching system for kitesailing, not least because is done well away from land obstacles and other water users. 

When most other things are sorted, we'll also fit a full kite winch system such as used on our previous large kite boat (1991 I think).  Originally we used the winch system as a kite launch aid- launching the kite on short lines then letting it up, much as Corey Roeseler does with the "KiteSki", but with the Arc and WipiKa style kites it is less necessary to do this.  The winch's main usefulness now is "line hygiene", to reduce line tangling while letting out and pulling in- left loose in the water, lines are magnetically attracted to rudders etc.

The goal, is as it was in 1988- to develop kitesailing to match conventional sailing craft: Enclosed waters first, coastal next and full off-shore as the ultimate.  The systems on this boat are the bridge from enclosed to coastal.

So much progress now, so tantilisingly close.

Damn, so much to try yet, so much fun coming up, but summer is drawing to a close here and I have to start on my annual northern migration.  All I have to look forward to is 6 boatless months or so of lying around on the beaches of Italy and points further north.  At least I can dream on no matter where I am, but Damn!

*Some would say my vision is a bit blurred even when looking straight ahead, ha ha.

Peter Lynn, Ashburton, Feb 28 '01.