Anchor test

[tradmanclimbz]

The budget is a bit streatched  so I have been useing 5/16th quick links for anchors instead of the usual 3/8ths. I know they are pleanty strong but just for reasurance sake I did a little test  over the weekend.

I used a 1/4" quick link made in Malaysa and rated at SWL 880lbs which is roughly 1/2 the SWL of a 5/16th quicklink.
Tied the rope to a tree with single bowline.
Loose coil on ground.
other end of rope has overhand fig 8.
1/4in quick link through loop created by overhand fig eight. Quick link was hand tightened.
Old retired locker w/ broken locking collar attaches 1/4 in quicklink to bumper of F150.
Rope is retired single rope. appears to be  roughly 10.5mm
Mosh accelerator on F150.  When the loose coil runs out and that truck hits the end of the rope you are esentually drop testing with a pickup truck.

The result is the rope breaks at the knott.  The rope always breaks at the knott. If there is a bowline in the system the rope always breaks at the bowline. The next point of breakage will be an overhand on a bight. The rope will only break @ a fig 8 if there is no  bowline or overhand on bight in the system.
 Hard to tell from the photo but the  rope broke in the center of the knott just left of the  broken end.

[M_Sprague]

There has got to be a better place you can save a buck than cheeping out on anchors, Tradman. They may pass your ad hoc testing, but I want extra beef to leave plenty of leeway for variable quality control and wear. Plus, the bigger radius is better for your rope. I can see using 3/8" instead of 1/2 to save money (not to mention carrying the beasts), but 5/16 is cutting it close IMO. I know it is sacrilege, but I would drink one less beer and stick with the bigger ones.

[sneoh]

.... but I want extra beef to leave plenty of leeway for variable quality control and wear. Plus, the bigger radius is better for your rope.

I was thinking along the same line too ....

[OldEric]

You could afford better quality gear if you weren't always having to repair your truck from the effects of your hair brained schemes.  The $$$ you spent on gas alone - "moshing the accelerator" - probably would have paid for it.

[tradmanclimbz]

 The actual bolt inside the sleave of a 3/8ths  5 piece bolt is 5/16ths. I BROKE a 10.5mm rope with a 1/4 in quick link. The 5/16th quick link is rated TWICE  as strong as the 1/4in quick link. That is pleanty of leeway for quality control INMOP. Of course if anyone wants to donate money for my bolt and anchor fund please let me know. I will be happy to take donations
Furthermore I will bet anyone, anytime $1,000 that I can break their dynamic climbing rope with a 5/16ths quicklink and that the break will Not occure at the contact point with the 5/16th radius. You supply the dynamic climbing rope and the $1,000

[tradmanclimbz]

+1 to Eric    The truck is getting tired....    I hear you on the longer wear issue but this place is off the beaten path. Also you may always feel free to rappel on those top anchors rather than lowering which will do far more to prolong anchor life than me useing a 3/8th s over a 5/16ths quicklink.

[tradmanclimbz]

BTW when I replace anchors @ busy areas I do use 3/8ths or larger to address the wear issue.  Currently needing 4 1/2in glue ins for the top of Monkey and Center Crack @ deer Leap... Mark, If 5/16th steel link feels too wimpy for you you should come ice climbing with me next winter I recently read tests that contrary to the rumor that V threads were stronger than ice screws they are in fact only about as strong as a 10cm Stubby screw

[apbt1976]

BTW when I replace anchors @ busy areas I do use 3/8ths or larger to address the wear issue.  Currently needing 4 1/2in glue ins for the top of Monkey and Center Crack @ deer Leap... Mark, If 5/16th steel link feels too wimpy for you you should come ice climbing with me next winter I recently read tests that contrary to the rumor that V threads were stronger than ice screws they are in fact only about as strong as a 10cm Stubby screw

Where did you read those tests? I love that kinda info. Don't be Scrooge!!!

[sneoh]

BTW when I replace anchors @ busy areas I do use 3/8ths or larger to address the wear issue.  Currently needing 4 1/2in glue ins for the top of Monkey and Center Crack @ deer Leap...

Good to know.  THX, Tradman.
You are right, it is usually not the size of the link that makes an anchor dodgy, it is the wear.  I still recall with horror some of the half-worn open-shut anchors we rapped from at Owens River Gorge back in the mid 90's.  I wonder what the failure load is for those ticking time bombs!

[tradmanclimbz]

I think that ice screw/ Vthread test was over on Neice?

[perswig]

http://www.itrsonline.org/PapersFolder/2009/SmithGordon-Allen2009_ITRSPaper_VThread.pdf
V-thread vs A-thread

http://neice.com/2012/02/ice-climbing-anchor-strength/
Abstracts and links to a plethora of ice anchor nitty-gritty.

Dale

[strandman]

I agree with Mark,, EXCEPT for the "one less beer thing""   

[M_Sprague]

All I know is that I have never been able to break a 3/8" or bigger one through telekinesis, so that is good enough for me.

[tradmanclimbz]

Seriously if you have any doubts about 5/15th quicklink being strong enough for climbing anchor you should never clip a 3/8th 5 piece as that is really a 5/16th bolt. The 5/16th link will break any dynamic climbing rope made.  In busy areas i totally agree that the rope bearing link should be larger for longer service life but have absolute confidence in useing the 5/16th to connect the  fatter rope end link to the anchor bolt.
 For the obscure areas that I am useing them, over use is not an issue. As for safty I am 1,000% confident that my anchors are bombproof.

Additionaly, the 5/16th link may even be a better choice than  3/8th fixe rings simply because it is easier to replace if worn as well as more reasonably priced.

[tradmanclimbz]

BTW I am useing Climb tech quicklinks. Not the Malasian hardeware store variety FWIW