Pegs part 2……

Just before I dash out for my bimble+overnighter this afternoon, I think I have a method of assessing the staying power of my pegs. I have gotten hold of a “fishermans hook” type balance that will measure weight up to 40kg. Although I could probably work it out eventually (I’m a brewer not a physicist!), if we convert kg into units of force we have roughly 1kg = 9.81 Newtons. At that point I have exhausted my pressure knowledge and leave it to others to further refine into KPa/Psi etc etc. Actually it doesnt really matter as long as we have something comparative to use as a yard stick for each type of peg….

The method

Place peg into the ground vertically and all the way down until there remains just enough of the top of the peg to allow for guyline attachment (about 2cm). Rig up a simple loop of guyline and attach this to the top of the peg. Attach the other end of the guyline to the “hook” of the fishermans scales. Initial trials suggest for ease of doing this the line be fairly short (12 inches). In fact, you can use any-type of string or line for this, doesnt necessarily make a difference for the purpose of the test although it should be robust!!! Watching the scales, see what the maximum force is needed to put the peg out of the ground when pulling the fishermans scales up vertically. Also you can measure the force required to start to move the peg,etc etc…… Ok, this is a very blunt method of trying to estimate the “gripping power” of a peg but it gives an estimation  

On a trial in the garden last night, I looked at the 3 pegs mentioned in my initial post and did some basic measurements. The ground was firm but stoney although I had no trouble pushing the pegs all the way in. The results as follows:

The titanium skewer peg took meaasured between 7 and 8 kg or approximately 70 to 80 Newtons of pressure to pull it out of the ground

The V peg took approximately 11 to 12kg or 110 to 120 Newtons of pressure to lift it out of the ground

The Y peg took approximately 10 to 11kg or 100 to 110 Newtons of pressure to pull it out of the ground

A couple of things then. It is very rough and ready, you are only seeing the gripping power of each peg with vertical force (real life puts multi-directional forces and strains on pegs) and the readout on the scales bounces around somewhat. Having said all that, my initial results seem to indicate that the V peg is slightly better than the Y peg and both are better than the skewer peg. I will take my scales and pegs with me this afternoon and try to find a few different ground types to test this method on (wet/boggy ground shouldnt be hard to find where I am going 🙂 )

Further, more elaborate, tests will follow when I have reviewed the initial measurements.

Round 1 to the V peg

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About Saddlebags and Backpacks - a brewer's outdoor adventures

I am a keen hiker, camper, cyclist and general all round gear addict..... I also manage to be a professional brewer in my non-spare time :->
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8 Responses to Pegs part 2……

  1. Simon says:

    Without putting my scientist hat on (that is firmly in storage these days), it is worth saying that a mixed peg strategy is a useful one. V pegs certainly stay in the ground better than skewers … as long as you can actually get them into the ground in the first place! On hard and stony ground I’m always glad to have a skewer to hand after trying and failing to get a V peg into place.

    Another thing that you can do with a peg of any kind in very soft ground is to double peg. It’s easier to draw a picture of this than describe it but if you can image a peg placed in the ground as normal as your starting point…

    … then a second peg is placed 6 inches further out in line with the guy and the first peg. The guy (or another piece of cord) runs parallel to the ground from the first peg to the second.

    Why does this help? Well when the guy pulls on the first peg the peg starts to move through the soft ground around a pivot point somewhere along its length. If the top of end of the lever (i.e. the top end) is being held by its own mini-guy then the chances of the peg pulling out are dramatically reduced.

    Of course you can only do this if you have a couple of spare pegs! So all the more reason to carry a couple of skewers with your V or Y pegs!

    • backpackbrewer says:

      thanks Simon. I always misunderstood the meaning of double pegging and assumed (and did myself) to put 2 pegs at 90degrees to each other.

      Whichever way, always take spare pegs and a mix of them too

  2. Roger says:

    Fascinating, given the surface area of each peg, it would seem to me that gripping power is related to friction so the greater surface are the greater friction. So my question is which has the greater surface area? And which has the greater sliding resistance to the soil?

    Okay a bit scientific, but my guess is that the y pegs have a greater surface are and therefore resistance to sliding in the soil.

    Look forward to your further comments

    • backpackbrewer says:

      Hi Roger,

      having been out this weekend I have further obseravtions so await the next enthralling installment coming soon….! 😀

  3. R MacE says:

    It’s worth trying to conduct some kind of repeatable test but it needs to be remembered that pegs when used in the real world aren’t normally subjected to a constant force. In strong winds the pressure increases and decreases as the wind gusts, think of pulling a nail out of a piece of wood, you’ll never pull it out without wiggling it back and forth, the peg is subjected to the same constant back and forth movement.

    In use pegs tend to be pulled at around 90° to their length rather than a straight up pull, in addition the leverage is reduced if the peg can be inserted all the way, if the peg is only inserted half way and the guyline slips up to the top/hook the leverage is increased while the holding power is similarily reduced, a short thin peg pushed in to the limit may well hold better than a longer thicker peg that’s sticking up out of the ground.

    • backpackbrewer says:

      completely agree Mac,

      was trying to keep the testing simple to see what kind of staying power under reproducible conditions each type of peg has

      I did try pulling pegs at 45degres to the perpendicular and it is more difficult to pull the pegs out

  4. Good bit of work. Interesting to see that V pegs offer slightly more resistance than Y pegs. I wonder if this would be the same for different soil types ? Simon, you are right about taking different peg types on a trip. I always like to take a v pegs for the end poles on a single hoop tent as much less likely to pull out than skewers, but as you say as long as you can get them in. Thanks for the tip on double pegging.

    Pegging in snow requires a different approach – Perhaps a separate post for backpackbrewer 🙂
    Mark

    • backpackbrewer says:

      Mark,

      without spoiling the next post too much, there wasnt a difference to the order of merit of pegs in different conditions

      my next post will reveal all 🙂

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