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How do tent stakes interact with soils to create holding power?


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Home Forums Campfire Editor’s Roundtable How do tent stakes interact with soils to create holding power?

Viewing 25 posts - 51 through 75 (of 75 total)
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  • #3823447
    Terran Terran
    BPL Member

    @terran

    A light tap on the stake can break that bond.

    #3823497
    Roger Caffin
    BPL Member

    @rcaffin

    Locale: Wollemi & Kosciusko NPs, Europe

    Yes, just a light tap will break the bond between ice and titanium.

    But not the bond between ice and aluminium.
    Ah – but if everything was sub-zero in the evening and overnight, there may not be any ice around: it may all be snow. Here in Oz it can often be just a shade above zero in the late afternoon – wet snow, and that does turn into ice overnight. I have had to use an ice axe to get my Al stakes out a few times.

    Cheers

    #3823516
    Terran Terran
    BPL Member

    @terran

    Sounds ionic.

    I got caught in that ice a few days ago. Went down a snowy hill. Then up an icy one the next morning.

    #3823523
    Geoff Caplan
    BPL Member

    @geoffcaplan

    Locale: Lake District, Cumbria

    To take up the point above about the British Delta pegs, their holding power in soft ground really is extraordinary.

    Despite the weight, many of us Scots will carry a couple for any shelter that requires tension along a ridge. We often can’t avoid setting up in bog, and this is much the best way of ensuring your anchors won’t fail:

    Unfortunately they are focused on the family camping market, which is why their products are over-specified for lightweight use. I used to live round the corner from their office, and tried to interest them in a lighter version, but they felt the market would be too marginal. They sell in volume – visit any UK campsite and many of the big tents will be using their anchors.

    I’m no physicist and don’t pretend to fully understand the design, but moving the attachment point away from the shank of the peg itself does seem to improve holding power very substantially. Perhaps there’s an engineer here who can educate us?

    I believe that their patents have now expired. So the way seems open for an enterprising fabricator to experiment with a lighter version in aluminium or titanium. They said that this wouldn’t concern them, as it’s not a market they will ever target.

    I recently noticed a related idea on the Robens Starlight range. They triangulate the guy with a strap that extends out at ground level. The two straps meet on the ground in front of the peg. I suspect that the strap around the peg should be longer in the example below. Robens claim that this reduces the risk of the peg pulling. Again, are there any engineers here who can evaluate this claim?

    Edit: found a clearer picture of the Robens setup – reviewers seem quite impressed:

    #3823528
    Roger Caffin
    BPL Member

    @rcaffin

    Locale: Wollemi & Kosciusko NPs, Europe

    Yes, there is a difference.
    When the guy is around the top of the peg, there is force trying to tilt the peg forwards. This displaces the top layer of soil. It can be weak.
    But the Delta design relies on the stiffness of the material and transfers the force to a point deep down near the tip – underground. I am not surprised they work well in soft Scots bog. :)

    Cheers
    PS: could they be made of sheet titanium? I suspect so.

    #3823539
    Jon Fong / Flat Cat Gear
    BPL Member

    @jonfong

    Locale: FLAT CAT GEAR

    Interestingly enough, I bought some material to tinker with this idea: deadman stakes.  What slowed me down was I have to develop some fixturing in order to bore a clean hole at a 45 degree angle into a tube.  The overal concept seems great to me.  Once the part is made, there will need to be a whole lot of testing to validate the concept.

    #3823540
    Roger Caffin
    BPL Member

    @rcaffin

    Locale: Wollemi & Kosciusko NPs, Europe

    Hi Geoff

    I believe that their patents have now expired. So the way seems open for an enterprising fabricator to experiment with a lighter version in aluminium or titanium. They said that this wouldn’t concern them, as it’s not a market they will ever target.

    Would you know what the patent number is? I have tried searching the government patent site but (like all things government) the web site is utterly useless for a search. Or any other information!

    Cheers

    #3823542
    Geoff Caplan
    BPL Member

    @geoffcaplan

    Locale: Lake District, Cumbria

    Roger

    Here is the US patent:

    https://patents.google.com/patent/US6619307B2/en

    The inventor was Robert Orr of Devon, who is sadly no longer with us.

    It expired due to fee related issues, but it is also over the 20 year limit. This limit would likely apply to any other international patents.

    The claim is quite narrow and relates to the channel profile of their original metal design. This feature isn’t actually present on their much more popular plastic design so far as I can judge.

    I doubt that the fundamental concept of a delta ground anchor would be defensible, even if the patents were active. I found prior art in the first half-dozen search results – there are dozens more ground anchor patents that could be explored. I did ask Dorothy Orr at Delta Ground Anchors explicitly whether there were any features that they regard as still protected, because at that point I was in touch with someone who was interested in producing a lightweight peg and we didn’t want to infringe on their rights. Her reply was notably vague and non-committal.

    Obviously any prospective manufacturer would have to do their own due diligence, but I suspect there’s no IP impediment.

    Re-reading my correspondence with Dorothy I see that though she did at one point say they weren’t interested in a lightweight version as I said above, at a later point she seemed to change her mind and say that it was something they might do in the future.

    Anyway – it’s an interesting concept. The main downside is that it’s tricky to carry. Any folding feature would likely add weight, cost and a potential point of failure, so I suspect it’s something that users would have to simply put up with.

    As a little bonus, I spotted something else that might tickle your fancy:

    #3823543
    Terran Terran
    BPL Member

    @terran

    Looks like we’re getting back to using an angled stake that’s already bent. I can see why they used a stiff plastic.

    #3823551
    Geoff Caplan
    BPL Member

    @geoffcaplan

    Locale: Lake District, Cumbria

    I’d completely forgotten – there’s a very smart lightweight variant on the Delta, the aluminium Titan, by Mark Turnbull, another Devon inventor. He’s a small cottage producer so they’re not cheap. But they do seem to be effective.

    One clever feature is the way they nest for easier carrying.

    I was waiting for the promised Ti version to save a bit of weight, but it never appeared. What he has done, though, is produce a range of sizes. The final design was released literally a couple of days ago.

    Like many inventors, it seems that he’s better at ideas than marketing, so hopefully folks here will consider giving him a bit of support and trying the product.

    https://www.youtube.com/watch?v=EgU0iNTeC3w

    https://www.facebook.com/titangroundanchor

    https://bestoutdoor.co.uk/shop/ols/products/titan-ground-anchor-set-of-4-medium-27g-ttn-grn-nch-set5

    #3823588
    Roger Caffin
    BPL Member

    @rcaffin

    Locale: Wollemi & Kosciusko NPs, Europe

    Hi Geoff

    Amazing stuff about the anchors! Thank you very much.
    Mind you, the Titan anchors at 2.5 mm thick – um – overkill maybe?

    As for the tunnel tent patent – WOW! 1904 no less! My tunnels are little different!

    Cheers
    Roger

    #3823589
    Roger Caffin
    BPL Member

    @rcaffin

    Locale: Wollemi & Kosciusko NPs, Europe

    Hi Geoff

    50 lb pull? I doubt my tent could take that sort of force on a guy rope. Slightly excessive methinks.
    I see that the peg pulled out of the ground rather than failing. I THINK the engineering could be significantly improved.
    Most of the time a straight 2.4 mm Ti wire is strong enough.

    Cheers

    #3823590
    Jon Fong / Flat Cat Gear
    BPL Member

    @jonfong

    Locale: FLAT CAT GEAR

    50 lb pull?

    50 Kg!  Impressive.

    #3823617
    Roger Caffin
    BPL Member

    @rcaffin

    Locale: Wollemi & Kosciusko NPs, Europe

    Geoff

    Email me would you please?
    [email protected]

    Cheers

    #3823637
    Terran Terran
    BPL Member

    @terran

    That Robins Starlight looks similar to the pitch locks on a TarpTent SS. I use a longer stake in that spot because they tend to pull out. Extending the staking point helps, but tends to pull up on the floor as  evidenced by the raised buckle in your picture.

    #3823638
    Terran Terran
    BPL Member

    @terran

    #3823639
    Geoff Caplan
    BPL Member

    @geoffcaplan

    Locale: Lake District, Cumbria

    I’ve been on a thread where Dan Durston explained in exquisite detail why he believes that the default rigging for the pitchlocks is too short, and likely to lever out the peg in windy conditions. Though I presume that Henry Shires would disagree…

    #3823640
    Terran Terran
    BPL Member

    @terran

    I’ve asked. Henry Shires just says to use a longer stake. “Dixie” had the same issue in one of her videos. Using 2 needle stakes in an extended “y” configuration holds, but the extension needs to be extremely short or the floor floats putting extra stress on the tent when laying down.  I love the tent otherwise. A long stake at the point of intersection tends to work best. Though still not perfect.

    #3823641
    Terran Terran
    BPL Member

    @terran

    YouTube video

    #3823661
    Roger Caffin
    BPL Member

    @rcaffin

    Locale: Wollemi & Kosciusko NPs, Europe

    Henry Shires just says to use a longer stake.
    How very pragmatic – and very simple.
    And even effective.

    Cheers

    #3823697
    Terran Terran
    BPL Member

    @terran

    A couple of caveats.
    1. Dixies stake wasn’t fully inserted. 2. If I had been in my tent, my weight would have possibly prevented the stake from being lifted. 3. It’s not a 4 season tent. 4. High wind with a heavy snow load is more devastating than high winds alone.
    Not that others haven’t encountered the same problem. I’ve seen a couple different solutions. A minor nuance, the point being is there are flaws in that configuration. The anchors may work well in the bog. Putting them into sandy loam is a different story.

    #3823717
    Roger Caffin
    BPL Member

    @rcaffin

    Locale: Wollemi & Kosciusko NPs, Europe

    Putting them into sandy loam is a different story.
    Indeed. Soft stuff without roots is very difficult.
    On sandy river banks I use dead sticks at least 300 mm long, fully inserted.

    Cheers

    #3823744
    Jerry Adams
    BPL Member

    @retiredjerry

    Locale: Oregon and Washington

    I like TTs picture of collapsed tent.  That happens to my mid some, sometimes.

    You just have to tap all the sides from the inside and it will knock the snow off

    It creates a huge condensation problem on the inside walls

    #3823760
    Terran Terran
    BPL Member

    @terran

    Agreed. But I was in the house. I was testing. I considered it a success. I would have survived. The tent never totally collapsed and there was still room inside. I since replaced the stakes for the pitchlock ends and now turn them away from the wind. I learned the easy way.

    Had I been in the tent, I would have been more defensive, plus my weight would have held it down and kept it from blowing.

     

    #3823765
    Jerry Adams
    BPL Member

    @retiredjerry

    Locale: Oregon and Washington

    Yeah, that’s what happens to me, it looks bad until you knock the snow off

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