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Technical question: Anyone knows anything about flukes?

Posted: Fri Jan 15, 2010 9:07 am
by seadweller
I bought a fluke and when I looked in the back, I see some orange stuff and looks like the tubing was reconnected .... is that common for the back of the fluke? In adition, I notice two different kinds of tubing used ... looks like someone did a custom job .... the seller has no clue ....

Here are some pics:

http://s703.photobucket.com/albums/ww32 ... %20Flukes/

password: fluke101


thanks,
seadweller

Re: Technical question: Anyone knows anything about flukes?

Posted: Fri Jan 15, 2010 10:15 am
by mve
I am not familiar with snow flukes but from a pure engineering perspective, after analyzing the pictures here's what I think happened:

a) someone permanently attached a steel cable to this fluke using a welded tube

b) at some point the cable tore at one end of the fluke (top)

c) they crimped the torn cable end and welded it back to the fluke

Re: Technical question: Anyone knows anything about flukes?

Posted: Fri Jan 15, 2010 10:29 am
by HikeUp
Looks like this pair on eBay.

I'd guess the short piece of ribbed tubing is the crimping device that connects two loose ends of the cable, making a closed loop.

Re: Technical question: Anyone knows anything about flukes?

Posted: Fri Jan 15, 2010 2:17 pm
by bkk030580
I forwarded the photo to our team's snow anchor expert and here is his response:

I’ve done pull testing on many different types of snow anchors (including flukes) in many different snowpacks, and the most common failure mode for a fluke is not failure of the wire rope or failure of the blade of the fluke. Most often it’s how the fluke moves in the snowpack as it responds to a load. Most flukes are manufactured in a way that fixes the rake angle (i.e., the angle between the direction of pull and the plane of the fluke) so that the fluke will dig deeper when a load is applied. If it hits a hard layer, it will have a tendency to lay down and skate along the interface, and if it hits a layer of TG snow, it will pull through with significantly decreased resistance. Very rarely have I seen hardware failure while testing a fluke. In a few cases the wire rope broke, and in one, the wire rope tore through the blade of the fluke. Those tests, however, involved some seriously strong snow. As a rule of thumb, the snow usually fails before the hardware, but this assumes you’re working with good hardware. Homemade hardware and modified hardware is obviously questionable, and I’ve seen some homemade hardware fail at surprisingly low loads.

Going back to your fluke, the orange looks like it was simply the previous owner marking his gear, albeit rather copiously. I don’t see any damage to the blade of the fluke, so the tube and the swage are probably original components that MSR used to set the rake angle. For me the bigger question is not whether the part was modified, but whether one should ever trust their life (or their partner’s) to very old gear or used gear with an unknown history. How strong so you suppose that swage is after all these years? Is there any corrosion going on in there where you can’t see it? A brand new fluke only costs $30-40. Is it worth rolling the dice to save $30?

Re: Technical question: Anyone knows anything about flukes?

Posted: Fri Jan 15, 2010 4:52 pm
by PackerGreg
I once found toilet paper in a Forest Service outhouse, but it was a fluke!

Re: Technical question: Anyone knows anything about flukes?

Posted: Fri Jan 15, 2010 5:02 pm
by Bill
PackerGreg wrote:I once found toilet paper in a Forest Service outhouse, but it was a fluke!
Yeah, but was it stuck to your shoe? :lol:

Re: Technical question: Anyone knows anything about flukes?

Posted: Fri Jan 15, 2010 5:28 pm
by PackerGreg
:) There's a reason we call it "Mountain Money" - it's valuable, hard to come by and you would trade with just about anything when in need.

Re: Technical question: Anyone knows anything about flukes?

Posted: Wed Jan 20, 2010 4:15 pm
by Rumpled
I thought you might be talking about the parasitic flukes - use flagyl.
Actually, I'm not sure about that. I took a parasitology course in college and one of the recommendations was if you didn't know the treatment on the test, put flagyl; it was the most common and might be right.