Is it possible that we have the whole British boat strength versus weight conundrum wrong? Certainly the British boats are laid-up by hand and not vacuum bagged. Certainly vacuum bagging results in the higher strength to weight ratio. But how is this strength defined? Tensile only, if my not-in-the-business mind is not mistaken. The glass fibers in Fiberglas are strong, very strong but in tension only. What provides the other components of this thing we call strength? The compression resistance, deflection resistance, torsional strength, abrasion resistance, shear strength, to what degree are these other properties required and in what parts of the boat? The durability issue is so much more than strength versus weight. I have owned more than a few North American built boats that were beautiful, very light, very capable of handling heavy water but were built as if they'd never see action beyond flat water, sandy beaches and protected launches/landings. All of my experience now leads me to the British boats. They are not, to my eye, the most appealing. Nor are they, to anyone's arms, the lightest. They seem to be, to many of the most experienced of us, the most durable and tolerant of rough handling, the proverbial "battleship". It seems to me that a Seakayaker magazine review has more than enough marketing clout to warrant a boat at no cost for long term testing followed by (possibly destructive) strength tests. Such a boat should be plucked from a distributors stock rather than be picked by the manufacturer or worse yet built specifically for the test. Full boats would be required, not panels, much of a designs strength is in the form/material combination. Certainly the experts at Paddlewise could design a worthwhile and comprehensive series of tests. If Seakayaker is too busy to do the testing then It would be easy enough to set up a test facility in New England and send the results to them for publishing. Ultimately the buying public will purchase boats for a variety of reasons, rather than solely the outcome of these tests and reviews. Who among us hasn't bought a boat just because it was beautiful or paddled like a dream in some narrow application or had some design feature that we just couldn't live without? I agree the a significant effort would be required to develop the testing procedures. Even then many will clamor that the test, are either unfair or arbitrary or unrealistic or biased. So we must include all of the manufacturers in the test design process. But this should be a "Consumers Guide" kind of test regime. Some tests would require the boat to be in the water other should be done on dry land. They all should be real life scenarios or laboratory approximations of same. We paddlers would carry the ultimate power over which tests we value. The Tests (a work in progress) -- primarily fiberglass for now but tests for plastic boats would also be required. Resistance to "Oil Canning" is mainly a design issue more that a pure strength issue. If a section of the boat can flex to absorb a force without cracking or weakening then that would be great, but most times the flexing leads to stress or compression cracks. So we should test for not only "Oil canning" but also material fatigue from repetitive "Oil Canning" at various temperatures. Resistance to cracking of the hull and deck in areas likely to see compressive forces. Situations like paddle float reentry's, X rescues, sitting on the deck or sitting on the hull with the boat upside down. Impact Resistance Dropping the boat as if it fell off the rack. Drop various paddling related objects onto the deck. Hitting submerged rocks. Whack the boat into something while being carried. Abrasion resistance Run the boats up onto and /or drag them over rocky shores Penetration Resistance, Shear Strength I'm not sure how to define these or how valuable they might be. Other test that might benefit from more scientific testing Weathercocking, tracking, maneuverability (even keel and tilted) Certainly not strength related but may use much of the same equipment as other "strength related" test. Certainly the list could go on and on. Please add as you see fit. I'm willing, at the mere hint of interest by someone like Seakayaker Mag to compile your responses, poll the manufacturers and get this thing rolling. Paddle On Garth Jed *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
In a message dated 1/6/00 3:48:53 PM !!!First Boot!!!, LedJube_at_aol.com writes: << Certainly the experts at Paddlewise could design a worthwhile and comprehensive series of tests. >> I would think time and commercial use to be good testing scenario. The competition to sell boats and the proliferation of "new" designs offered limits the time and use tests. After three to five years of use, the subject boats would no longer be available or would not be the "new and shiny" model. Bruce McC WEO www.wholeearthoutfitters.com *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
----- Original Message ----- From: <LedJube_at_aol.com> To: <paddlewise_at_lists.intelenet.net> Sent: Thursday, January 06, 2000 9:25 AM Subject: [Paddlewise] Durability Testing (Seakayaker Mag are you listening?) > ... > The Tests (a work in progress) -- primarily fiberglass for now but tests for > plastic boats would also be required. > > Resistance to "Oil Canning" is mainly a design issue more that a pure > strength issue. If a section of the boat can flex to absorb a force without > cracking or weakening then that would be great, but most times the flexing > leads to stress or compression cracks. So we should test for not only "Oil > canning" but also material fatigue from repetitive "Oil Canning" at various > temperatures. > > Resistance to cracking of the hull and deck in areas likely to see > compressive forces. Situations like paddle float reentry's, X rescues, > sitting on the deck or sitting on the hull with the boat upside down. > > Impact Resistance > Dropping the boat as if it fell off the rack. Drop various paddling > related objects onto the deck. Hitting submerged rocks. Whack the boat into > something while being carried. > > Abrasion resistance > Run the boats up onto and /or drag them over rocky shores > > Penetration Resistance, Shear Strength > I'm not sure how to define these or how valuable they might be. > > Other test that might benefit from more scientific testing > Weathercocking, tracking, maneuverability (even keel and tilted) > Certainly not strength related but may use much of the same equipment as > other "strength related" test. > > Certainly the list could go on and on. Please add as you see fit. I'm > willing, at the mere hint of interest by someone like Seakayaker Mag to > compile your responses, poll the manufacturers and get this thing rolling. > Wow, this could get very expensive. I think it would be very difficult to get quantitatively useful results. An important is the question what is their durability and safety after experiencing these abuses. To really understand the durability of a boat you have to use _many_ copies of the same boat and do _many_ tests like: - Drop a boat off the rack x times, then measure the force it takes to snap the boat in half by folding it - Drop a boat off the rack x times, then measure the force it takes to compromise the deck by dropping a load on it. - Drop a boat off the rack x times, then measure the force it takes to flatten the boat to a height of 2" by applying pressure plate from the top and bottom. - Drop a boat off the rack x times, then measure the force it take to puncture the hull in - Drop a boat off the rack x times, then see if it oil cans - Drop a boat off the rack x times, then see if its deck-hull seam leaks - Drag the boat Y yards across rocky shores, then measure the force it takes to snap the boat in half by folding it - Drag the boat Y yards across rocky shores, then measure the force it takes to compromise the deck by dropping a load on it. - Drag the boat Y yards across rocky shores, then measure the force it takes to flatten the boat to a height of 2" by applying pressure plate from the top and bottom. - Drag the boat Y yards across rocky shores, then measure the force it take to puncture the hull in - Drag the boat Y yards across rocky shores, then see if it oil cans - Drag the boat Y yards across rocky shores, then see if its deck-hull seam leaks ... And then you'd have to combine abuses in different combinations, then determine the above outcomes. And then you'd have to repeat it all many times to prove that a particular failure wasn't the result of a boat that was contributing to the low end of the mean-time-to-failure curve. Very expensive. If this sounds extreme, then consider the way that cars's safety is determined (that is fully assembled cars). You crash them and measure forces exerted on things like test dummies. Because of the cost, you're probably only going to get three type of crashes tested: full-frontal (don't search for this one :-), frontal-offset, and side-impact. And that's if you're lucky and somebody cared enough to test the car you want information for. An unfortunate problem with this testing method is that we never find out if the results of the tests are repeatable. It's not enough to do a test just once. You've got to repeat it (perferrably with a third party) to know for sure. What the auto industry/government does, however, to compensate for this pragmatic inability to conduct real science in measuring the safety/durability of a vehicle is to keep databases of incidents. This allows us to go back, in retrospect, and review the quality of a particular model. Unlike finance where past performance is not indicative of future potential, these database can be representative of a manufacturer's quality. So, what's my point? I don't really know, I'm just blathering. Maybe the points are: - When (and if) anyone ever devises a durability test, be skeptical about its ability to answer the question, "should I buy boat X instead of boat Y." - It can only be good for us (consumers) to get the word out about the problems we encounter; this is much like the paddler safety incident articles in Sea Kayaker and those in other magazines like Flying. Smart people learn from failures. Evan *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
Just out of curiosity, are there any PaddleWisers out there who own Tsunamis? How do you feel about their durability vs. the Brit. Battleships? LedJube_at_aol.com wrote: > > Is it possible that we have the whole British boat strength versus weight > conundrum wrong? Certainly the British boats are laid-up by hand and not > vacuum bagged. Certainly vacuum bagging results in the higher strength to > weight ratio. But how is this strength defined? Tensile only, if my > not-in-the-business mind is not mistaken. The glass fibers in Fiberglas are > strong, very strong but in tension only. What provides the other components > of this thing we call strength? The compression resistance, deflection > resistance, torsional strength, abrasion resistance, shear strength, to what > degree are these other properties required and in what parts of the boat? > > The durability issue is so much more than strength versus weight. I have > owned more than a few North American built boats that were beautiful, very > light, very capable of handling heavy water but were built as if they'd never > see action beyond flat water, sandy beaches and protected launches/landings. > All of my experience now leads me to the British boats. They are not, to my > eye, the most appealing. Nor are they, to anyone's arms, the lightest. They > seem to be, to many of the most experienced of us, the most durable and > tolerant of rough handling, the proverbial "battleship". *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
In a message dated 1/6/00 4:55:14 PM, Outfit3029 writes: << I would think time and commercial use to be good testing scenario. The competition to sell boats and the proliferation of "new" designs offered limits the time and use tests. After three to five years of use, the subject boats would no longer be available or would not be the "new and shiny" model.>> This would make a great, although subjective, test for general durability, fit/finish, comfort and general utility but I think the strength tests would have to be done in a lab to yield empirical data. More than one boat would be required for a commercial use test so that results won't be skewed by exceptions. I do want to say that I feel Seakayaker Mag does a great job already with the subjective side of boat testing and reviews, except for the durability stuff The time issue is well taken. The testing could start soon after production boats are at the distributors to make sure were not testing prototypes How would we keep the manufacturers from changing/lightening the construction after the tests has been published? Maybe the builder could guaranty the construction spec's and each model could be retested every two or three years. As far as publishing test results early in the boats life-cycle: This will always be a compromise. Too early and correlations are weak. Too late and the information loses it's value. But the "new and shiny" model mindset is problematic. Kayak designs, at least the good ones, stick around for quite a while. I think a 12 to 18 month period from production start to tests publication is not excessive or unreasonable. This point too should be decided by the governing body with input from all interested parties. Jed Luby, SKDST (Senior Kayak Durability and Strength Tester) North American Institute of Kayak Studies *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:33:06 PDT