Is product development technically effective or unecessarily complex?

[Rupe]

dont be cheeky boy.

 

 

 

Ha, ha. Knew you would catch up at some point!

[scotspine1]

Ha! I like the caveat Craig.....like I'm almost garaunteed to upset anyone at any moment!

 

Tim

 

I'd say the Helical is for you, tied with 10mm cord. The new ISC pulley looks like it was made for it. Don't ask me what its called - Judge will know, and I'm sure he'll supply it at a credit crunch worthy price.

 

i'll give it a go. Is there any place on the net where it explains how to tie it? Rupe, is this the best way to tie it?

[Peter]

The helical is a cavers knot, try one of their websites for full instructions.

I normally tie it with a shorter leg, have it closer the the biner, and put the slack tending pulley straight on the biner, but each to their own.

 

Make sure the cord is strong enough to take the loading on a single leg though.

[Mr Ed]

Looks like a good transition knot for us old time Blakes users then...

[scotspine1]

Looks like a good transition knot for us old time Blakes users then...

 

Dunno bout that Ed, I've tried the VT for months at a time but always gone back to the Blakes. Just would like to find a way of slack tending like the VT, but the problem is the 13mm split tail wont advance easy. I'll give the Helical a try once I know for sure how its tied.

 

Thanks for the info Peter, found this pic - looks nothing like Rupes, there's also a pic on Laz's friction hitch pdf he did for the HSE but it looks unfinished, the pulley is twisted.

 

http://www.forestry.gov.uk/pdf/FCRR-JD-0402.pdf/$FILE/FCRR-JD-0402.pdf

Edited December 16, 2008 by scotspine1

[Peter]

That is the exact same knot, tied but not dressed.

[Laz]

Tim

 

Sorry about the pics, but I'm afraid I had nothing to do with the photos or formatting - I severed ties with TV before the report formatting was completed. I agree some of the pics are not best presented. Its not me in any of the pics either (cause people often assume). That would be Richard Almond.

 

Anyway, the Helical performed as well as any hitch in the tests.

 

The testing showed that the philosophy that a double leg hitch is stronger than a single leg is flawed; when the hitch tightens enough to test the breaking strength, heat is generated which causes the braids to weld to the line. In the tests, this caused at least one VT hitch to fail twice during the pull before releasing the load.

 

In comparison, one Blakes tied with 13mm single braid exploded at much lower loads. In fact, the wraps seemed to have vapourised, as only two straight sections of cord could be found. That was the strongest cordage used, but it didn't perform as highly.

 

I made note of some specific insights during testing, that were never made public: After the report was completed, a meeting was held to discuss the findings and establish industry best practice. I wasn't invited because I was neither a verifier or a member of TV. Obviously doing all the research and word processing means I had nothing further to offer.

 

It has always been my intention to write a summary of the research for the Arb journal with better graphics and photos to present the data in a more user friendly way.......... but no time or funding is available to me.

 

Until then, based on the test results and cordage used, I recommend a minimum breaking strength of 1700Kg, polyester/ nylon, of double braid or kernmantle construction and 8-10mm diameter on 11-13mm lines, for all the friction hitches save the Blakes (thinner cords tend to bite too tight with this hitch).

 

The success I had with tying the Helical, was to set the braids before tying the bowline, unlike your second photo.

Edited December 17, 2008 by Laz

[Craig Johnson]

how i run mine!

Edited December 17, 2008 by Monkey-D

[High Scale]

I must give that a try.

[Mr Ed]

Dunno bout that Ed, I've tried the VT for months at a time but always gone back to the Blakes. http://www.forestry.gov.uk/pdf/FCRR-JD-0402.pdf//FCRR-JD-0402.pdf

 

 

Same here Tim, tried the VT lots, but I keep returning to the blakes like an old friend.