Re: [Paddlewise] [PaddleWise] Skin on Frame Boats

In a message dated 9/20/2004 11:59:48 AM Pacific Daylight Time, 
pac_at_premier1.net writes:


> Ramming rocks is not what they were designed for, and not
> what most people would consider "normal" use in a sea kayak.

Depends on your definition of what normal means.

> 
> 
> the traditional SOF frame is a fail-safe redundant
> structure.  Very similar design is used on almost all modern air craft
> structures.  If any one member fails in the hull structure, the others carry
> the forces around the failed part, prevent a complete failure of the
> structure.  

Why can't we stick to a more tangible comparison? Why do we so often compare 
that which is way up in the clouds to what we paddle way under the wave crests?


> 
> 
> Landing on sharp hard rocks is another mode of failure that likely the
> hard-shells are better at than SOF, especially the roto molded hulls.
> Though all types of construction will get damaged in such an impact,
> individual frame members of the SOF would be more susceptible I think.
> Though as long as the skin does not get punctured (a real risk, but yet rare
> occurrence), you are still seaworthy.  In very serious impacts the
> fiberglass hull can completely collapse and/or puncture, making field
> repairs nearly impossible.  I think the SOF are superior in this instance
> since even if the skin is punctured, temp field repairs (if necessary at
> all) are relatively easy.  Of coarse the rotomolded hulls are great for such
> abuse, they only get scuffed and pop right back, which makes them great for
> a rental fleet.

I agree with you that a properly designed SOF is a very seaworthy and tough 
kayak. But, I would like you to qualify this a bit better. So far, it appears 
to be apples and pinapples you are judging. Nick Schade posted the following 
link on qajaqusa.org some time back, though for different reasons than this 
thread.

http://www.maineislandkayak.com/pdf/lib_bcutraining.pdf

The info I want you to consider is on page 7-9 of the 9 page report about the 
authors experiences in a BCU 5* training that had a boat crunching incident. 
What you seem to suggest is that in a very serious impact a complete failure 
is more likely in a glass boat than an SOF would sustain. Really? 

Were I in my SOF, I would not have paddled away from that incident as did the 
glass boat guy. In that scenario, I propose a standard SOF would have been 
sawed in half. OK, so that isn't normal use, but it doesn't give any credence to 
your suggestion of the superiority of the SOF.


> 
> 
> I think the SOF is a superior way to build a kayak, but unfortunately it
> does lend itself well to production nor to modern desires for bulkheads,
> hatches, rudders and other modern inventions.  I do not think there are any
> manufacturers of non-folding SOF kayaks, it is a shame since they can
> perform in many areas superior to hard-shell kayaks, and use much less
> materials and weigh much less too.  But again it takes proper careful and
> proper design to optimize either type of construction method.  And if the
> consumers of production kayaks are not comfortable with the idea of 25 to 30
> pound kayaks being just as safe and durable as 60 to 70 hard-shells, you
> will not be able to stay in business.
> 
Superior? How? How does a kayak of SOF construction BECOME superior because 
of its construction process? How does an SOF PERFORM better than a hardshell by 
virtue of its construction process? Could I replicate an outstanding SOF 
design in glass and make it perform as well? If I then added bulkheads and 
hatches, (to reduce floodable volume), could I then argue it was safer? I think you 
are describing your idea of the perfect fruit as a pineapple, when others 
believe it to be an apple.


Rob G
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