robertovillate wrote: tomatkins wrote:
As far as the "new-improved-board leash"...all this has been discussed for years...some sort of "fusible" link just does not work.
Finally, we are getting down to some details. What varieties of "fusible links" are you familiar with, and what has been your personal experience, or first-hand accounts from other's experience, with such "fusible links"?
In what specific ways have those particular links not worked?
This very valuable factual information may be the first step toward designing a "fusible link" that will work.
Thanks in advance for the information.
...Back when I was a naive novice I actually used a Reel Leash (around 2001 - 02)...
...The problem with the idea of a "fusible" link is that it will either be too strong for one particular situation and too weak for another (even on the same day within a few moments of time)....
...I had my board pull me underwater once in sea-anchor scenario (I had to cut the leash)....
...The board does not have to load very much to recoil under some circumstances, and a "sea-anchoring" board does not need that much load to skull itself underwater...
.... Also, if a board comes off your feet in a wave condition the leash may not be loaded much at all as the wave launches it toward you. ...
...There is no way that you could adjust the tension "on the fly" in a dire situation....
Thanks for responding to my questions.
Sorry to chop up your comments. I don't mean to take them out of context, and only do so to make it easier to respond to some of the points, you very competently make.
It looks like some of your past problems and concerns could be resolved through technology and leash design changes.
For background, I also used a reel leash in 2002, when I learned to kite... I think most of us did, whether we took lessons or not. Those, who took lessons, were "taught" how to use a leash, during their second lesson, after they did the downwind "teabagging" lesson. They were sent out on the water, to practice dragging their board behind them on a 'downwind-teabagging-kit -figure-eighting' run. We learned a lot about using a leash during that "lesson".. such things as what happens when you roll around and get the leash wrapped around your torso and legs... the board springing back and "bumping" you ... the hassle of trying to untangle the leash, after you did the 360 degree spin, in the water, with the bar overhead, to uncross the 4 (or maybe even 2) kite lines. That was lots of fun, wasn't it? Some of us never used a leash again, and just bought a set of "boots".
I would comment that a "fulible link" should always be designed to err on the "too weak" side. I think that it is possible to design an automatic force-triggered release mechanism, which could be adjusted "on the fly", but that doing so would not be very valuable, except at times when the kiter wanted to totally disable the auto-release mechanism. It would be a simple matter of moving the "trigger string" to a more slack position, as I can illustrate, if anyone is really interested in this design concept (just ask).
If the "fusible link" is designed to release at the "too weak" force, then, the kiter will occasionally have to "drag for the board", but the kiter may not have to use up most of his strength, and expose himself to the other possible hazzards in the water, for an excessive period of time, during his session on the water.
As far as dealing with a board that is "sea-anchoring", "tombstoning" or "fish-luring", the answer is simple, and would have saved you a lot of trouble, during the incident where you had to use a knife to cut through the leash. The answer to the problem is... just place a "push-away" safety releash on both the connection of the leash to your spreader bar, and also at the connection to the board. Here is a picture showing an example of this on a short board leash. You can see that the leash is attached to the very end of the board to help minimize the likely of "sea-anchoring", but in reality, the board will still dig down into the water, so I don't think that this connection point will completely solve the problem. However, maybe a "egg-shaped" foam float, located at this end of the leash might help. Lots of room for discussion and ideas here!... Maybe a "surface-planing-foil" device could be used to encourage the board to climb to the surface.
Also, it sounds like you are mainly referring to the use of a board leash on a "surfboard" and not a "twin-tip" board, although a lot of what you discussed pertains to both. A surfboard can really build up a "head of steam" while it careens down a wave face... whether it is on a leash or not... but I would make the point, that, at least, when it is on a leash, the surfer will have a good idea of which direction the board is likely to come at him from, and can get into a defensive stance, with his hand in front of his face, in that predetermined direction.
Anyways, thanks for taking the time to respond to my questions. If I have misrepresented you in any way, I apologise in advance, and welcome your corrections.
Here is a picture, showing the "guts" of the bungee tensioned automatice release device, which shows the "trigger string". This device is calibrated for 70 pounds of force, and in the past 2 years, has functioned flawlessly, first, through my testing program and later through the "beta" testing of my buddy, a beginner "test crash dummy", who liked the device, and the fact that he only had to drag for his board about one out of ten "crashes".
I would think that, if an instructor wanted to use any kind of a leash, during the instruction period, that this kind of a leash, would be a better choice than any of the leashes on the market, today. The main problem is that he would have to make such a leash, himself.