Two Point Self Equalizing Anchors on Rafts | Ep. 120

[@stacykiely961]

In your previous episode on a 3 point anchor system you stated that you prefer not to put the twist in the 3 point system because it does not allow the system to equalize as fluidly and you will retain a 2 point system if 1 D-Ring pops. Do you have more information regarding issues with not having a twist in the 3 point anchor system which led you to recommending it in this episode?

[@GearGarageTV]

No more information - since the twist isn’t necessary I don’t do it. It only minority affects the equalization so in my opinion it’s fine if you do add the twist.

[@jaredlinkhart6528]

The kids and I demoed that same boat at boating 101 last year. We had a blast with the boat, I think that size boat class is great! Love the color too!

[@calebteneyck3489]

When I was rigging pipe to install, we said the same thing only looking at it a bit different: the top angle of the triangle had to be less than 60deg(same as your less than120. An easy way to accomplish this is to measure between D rings and have the legs on the harness longer than that distance. So for the set up shown your total webbing length should be over 4 times the distance between D rings.

[@GearGarageTV]

Awesome advice. Thank you! I love the 4x rule.

[@steezjenkins]

Also a plumber/fitter/rigger. Yup same way. Nailed it!

[@SuperGoober64]

Years ago, we came across a group trying to extract a badly pinned raft on the Upper Wind. They had managed to break every accessible d-ring off of the raft and they were hanging from their spider web of ropes like Christmas ornaments. In their defense, it was the worst pin I've ever seen. The boat was 90% under water and being squeezed between two boulders so it's amazing they were able to get lines on the boat at all. As far as the angle on a 2-point anchor goes, one way to visualize why you don't want a flat angle is because basically that is creating a vector pull on the two d-rings which initially can generate about a 5:1 mechanical advantage. Combine that with the 3 or 5:1 system that you've got pulling on it and that is a lot of force. Thanks for doing these Zach, I always learn something new and it makes me think about things I have already had exposure to in a fresh light.

[@GearGarageTV]

Thanks for the story! A vector pull can theoretically create infinite force if the angle is 180 degrees.

[@delriv5238]

Excellent. Thanks Zach

[@debcarpenter74]

Lately, I've been using my winch to get the raft (14-foot Sotar, day trips) on the trailer. I'm thinking that I don't want to put the full pressure on 1 D-ring -- I can do the 2-anchor thing using the 2 rings just behind the bow ring (on both sides). Am I being too cautious? Also, please confirm the necessary angle degree -- is it less than 120 or less than 60 (as Caleb said -- maybe I misunderstood)? Thanks!!!

[@sandyradsek2058]

Is there any reason why you wouldn’t just clip the webbing to the D rings as you did in the second part vs running it through and tying a knot? Is there a preferred method?

[@GearGarageTV]

Sandy Radsek you could do that but it takes extra carabiners and extra time to make happen. Most of the time carabiners are in short supply.

[@kylevesely100]

Is it ok to attach to the frame if it is accessible?

[@GearGarageTV]

Yes but the times I've done that it hasn't gone too well. The rope system moves the frame but there is some give between the frame and the boat so the boat doesn't move.

[@debcarpenter74]

Never mind -- I found your statement and link from the previous episode on this topic "Here's a chart (www.ropebook.com/information/vector-forces) that demonstrates that if the angle between the 2 ropes is 120 degrees then the load on each anchor point is 100% of the main load." Thank you!