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  1. #1
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    Testing DIY ground anchors and stakes

    I am now on a quest for a ultra light ground anchor or staking option for use with a free-standing hammock setup. But before I can move to an ultra light version, it is important for me to get a few design criteria put in place. The most important of which is holding strength.
    Holding strength is crucial to me in Florida since 90% of the ground is sand and that makes matters all the worse.

    I have started testing a few configurations and have some numbers to share with the forum. My test bed is basicly loose to medium packed sand. If the anchor holds here, it will hold anywhere.

    1.
    Description: Standard 9" Coleman tent stake, 0.5" wide, aluminum
    Test setup: Drove stake to depth at approx. 30 degrees to the vertical. Pulled line at approx. 90 degrees to the stake
    Results: 18 lbs max , pulled out in expected direction

    2.
    Description: Standard 9" Coleman tent stake, 0.5" wide, aluminum, with hole 2.25" from the tip for line attachment
    Test setup: Drove stake to depth at approx. 30 degrees to the vertical. Pulled line at approx. 90 degrees to the stake
    Results: 12 lbs max, as the line became tight it did not cut through the sand to full depth, it began to pull the stake straight up and out of the ground

    3.
    Description: Standard 9" Coleman tent stake, 0.5" wide, aluminum, with hole 2.25" from the tip for line attachment , cut down to 5.25" and additional hole at 0.5" from new top
    Test setup: Drove stake to depth of 17" with 0.5" tube at approx. 30 degrees to the vertical. Pulled lower line to "set" the stake at approx. 30 degrees to the anchor
    Results: 20 lbs max, as the line became tight it definitely "set" the anchor, but then pulled the bottom of the anchor around and upwards.

    4.
    Description: 0.5" diameter pvc cut to 4.5" with slight angle at one end. 0.5" eye bolt screwed through the center and additional line attached to the back.
    Test setup: Drove anchor to depth of 17" with long screw driver at approx. 30 degrees to the vertical. Pulled lower line to "set" the stake at approx. 30 degrees to the anchor
    Results: 43 lbs max, as the line became tight it definitely "set" the anchor, the failure mode was simply pulling the whole anchor up through the sand.


    I have a few more ideas and setups to test, but if anyone else has similar data to share. Please do.

  2. #2
    WV's Avatar
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    Nice work. I like your approach to testing. See Alamosa's Stake Boom thread if you haven't already seen it. Also MSR snow stakes are nice - they're lighter than I expected, too.
    Last edited by WV; 12-18-2011 at 10:50.

  3. #3
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    Quote Originally Posted by WVassello View Post
    The most important of which is holding strength.
    Holding strength is crucial to me in Florida since 90% of the ground is sand and that makes matters all the worse.
    Quote Originally Posted by WV View Post
    Nice work. I like your approach to testing. See Alamosa's Stake Boom thread if you haven't already seen it. Also MSR snow stakes are nice - they're lighter than I expected, too.
    I have never moved on to the ultra-light options available for my Stake Booms as I really only intended to use them for Boy Scout or canoeing trips where I may not have an option of site selection. In both cases, weight is not a huge problem and having a 14 lbs. portable stand is not an issue.

    I have not tried it yet, but my thinking was that in sand, I could reverse the stake boom and drive the 1/2" tube into the sand and tie to the 3/8" stake. This would cause a much larger anchor in the sand. Not sure if the stake would hold up to the stress or just bend. May have to find a large sandbox to run some tests.

    The biggest problem with sand is that it is not cohesive, so it is easy to drag a stake through and out of it. I've thought that there must be a way to combine the boom with two flat stakes for sand. The two stakes would be connected in a way that limits how far they can separate from each other so that as they drag through the sand they act as rudders forcing sand from both sides into the middle.

    The idea being to convert the ripping force of a stake being drug through the sand into a compression force on the sand as it is forced between the two-part stake.

    Unfortunately, the farther I go with this idea, the farther I get from light weight.
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  4. #4
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    Sand options

    As I see it, you need maximum area to keep from pulling a stake from sand.

    The Coglahnds ABS stake is about an inch wide, with 9" length. You do the math.

    The SMC Sno Stake is also about an inch wide, and gives you the option of attaching a guyline toward the middlw of the stake to reduce rotational force.

    The SMC Sno Anchor looks to be the ultimate in terms of square inches. Should be stable as well. They are designed for snow anchorages and while pricey they should be veru difficult to pull out.

    All are available at REI.com.

    You might be able to fabricate anchors similar to the AMC Anchors out of PVC pipe, or 0.125 aluminum. But then you would have material cost close to the manufactured items.

    Jim
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  5. #5
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    Follow up to test data

    I will try and run down the list of questions as I remember them and go back over the posts and see what I missed.

    1. I used a digital scale that I use in my lab. It is rated to 100lbs, so I have some room to grow.

    2. My next round of testing will be with a stake boom style and a T-channel anchor that I am designing. I am open to testing more designs as time permits and as I have them available. As I am a non-profit entity, I won't be buying a bunch of pricey stakes simply to test. However, I will try and find similarly shaped geometry in my scrap bins and give an educated shot at it.

    3. Sand Sucks!! But as that is my worst enemy, and a potential situation, I will make my stand in the sand!! Sort of. I don't plan on using this on the beach, but even deep in the woodlands of Florida, its all sand.

  6. #6
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    Follow up

    4. The attachment point at the bottom of the standard stake would have seemed to work except for the tendancy of it to pull the stake directly up if the line does not cut completely through the ground. If it doesn't work in my situation, I can't see it helping anyone in any firmer ground. In the desert or snow, sure, but in firm ground not so much.
    UNLESS, (and I am kicking myself for not trying this) have someone stand on the stake while the line is pulled all the way to the bottom and cuts completely through the ground. Still seem far fetched for most of you, but in the soft ground it may work.

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    The problem with the plastic and even aluminum anchors mentioned is the amount of force that is going to be applied to them. Based on a 30* angle from hammock to stand and then a 45* angle from stand to anchor, using 2 anchors, you will be applying a force equal to your weight to each anchor (2/3 of your weight if using three anchors).

    Both the plastic stake and snow anchors are intended for holding a tent down, possibly a tarp, but I don't think they will stand up to the pressure of a hammock. IMO.
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  8. #8

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    This is valuable information. I hope others join in.

    May I ask how you are measuring the pull force? The reason I ask is so others can do similar tests with similar results, also to note that if you are successful, the force numbers will be larger. You may eventually need to measure pull-out up to 100 lbs or more.

    I don't have much sand available here, I have camped on the NC Outer Banks, though, where the sand is like sugar. The car campers there use very long stakes, or get blown away. I have watched this happen from my tent, when the wind picks up and neighboring tents were pitched using the stakes which came with their tent.
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  9. #9
    Prefers life at 12 MPH. FLRider's Avatar
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    The attachment point at the bottom certainly seems to work, from your data.

    It seems (and I may be wrong here) that the two most common methods for ensuring stake set in soft soil are to use a stake designed for that or to place something heavy over the head of the stake.

    The "Y" stakes sold by MSR (their Groundhog line) and similar seem to be very popular; I use a set, in sand, and have yet to have a problem with them. Note that I've not done scientific testing on them, though. This is anecdotal.

    The other stake I've seen popularized for multi-terrain use is aluminum gutter spikes (gutter nails) from the hardware store. I've not used these personally, so I can't comment upon their holding power.

    I'd be very interested to see what the rest of your testing turns up. Thanks for taking the time and effort to do it!

  10. #10
    Senior Member TiredFeet's Avatar
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    You don't mention where you are attaching the line to the stake. The higher the attachment point, the easier it is to pull the stake out. Ideally you want the line attached to the stake right at the ground.

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