Brian M wrote:Silly question, perhaps, but why are some folks concerned about recovering duckbill-style anchors? I'm fairly new to the backcountry gig, but duckbills are what I carry based on recommendations here and elsewhere. They're not expensive, so leaving them in the ground is mostly a non-issue for me. If they're so effective (which seems to be the case), why go with something that is less effective but maybe just a bit easier to retrieve?

This is my thought also. I leave them and mark them for either my use again. Or for some one else. They can be had pretty cheap on Amazon.

For those of you using duckbills, what size are you using? I'm guessing 68 or 88. How do you mark them when you leave them?

MTV, have you used the EAA anchor and if so how does it compare to FlyTies in your opinion?

Thanks.

Frank

fshaw wrote:For those of you using duckbills, what size are you using? I'm guessing 68 or 88. How do you mark them when you leave them?

MTV, have you used the EAA anchor and if so how does it compare to FlyTies in your opinion?

Thanks.

Frank

I think mine are 68s but I would have to look. I mark mine with either a piece of survey tape or put a circle of rocks around each one.

Leaving the duckbills behind:

At an airstrip that is mowed periodically, you can imagine the frustration the mower operator would have untangling and repairing clutch packs when encountering unseen cables in the grass.

In true back country ops, it probably wouldn't matter.

Brian M wrote:Silly question, perhaps, but why are some folks concerned about recovering duckbill-style anchors? I'm fairly new to the backcountry gig, but duckbills are what I carry based on recommendations here and elsewhere. They're not expensive, so leaving them in the ground is mostly a non-issue for me. If they're so effective (which seems to be the case), why go with something that is less effective but maybe just a bit easier to retrieve?

For me: Because nearly all of the areas I would use them get mowed (either be a conventional mower or a hay cutter or an industrial mower). I don't want to leave behind something that's going to trip up a mower.

I'm also kind of a general fan of not leaving my "garbage" behind.

But I'm also an outlier in this conversation in general. I figure that fly-ties (my tie down of choice) is enough for the vast majority of things and insurance is good for the rest.

Thanks for the responses. I hadn't considered the issue of strips being mowed. All of the instances where I need to install a tie-down are in the backcountry in Alaska where mowing isn't an issue. I've used duckbills left behind and marked by others, and it's certainly appreciated.

soyAnarchisto wrote:A removable duckbill with an amsteel line sounds interesting...

There's also these things. Seems better than plain old steel nails and three of them equalized with a bit of cord could be every bit as strong as flyties kit - and a lot lighter weight.



According to their facebook page, they load tested a large orange screw driven in at 45 degree angle at over 640lbs before pulling out. Like a flyties or claw, three of those per anchor (or more) would be hella-strong to hold a plane down.

Those are kinda cool. They are distinct from the doggy-anchors in that they are a true auger with a lot of flat surface area, and not just a helical wire. I'm thinking that must make a huge difference on direct pullout strength.

Like any tiedowns though, the medium they are being screwed into will be important.

Go to Grainger.com and in the search box enter earth anchors. Depending on soil, these work great. A bit heavy but not too bad. I just bought the 30"x3". We have used the 48 inchers for floatplane tie down in Alaska and Michigan. For portable I use and prefer Fly-Ties, I have had a set from 1994 if memory serves me correctly.

Kurt

I would think that an industrial earth anchor similar to this could be found locally in NZ:

https://americanearthanchors.com/files/ ... lation.pdf

I haven't used one...don't know how easy they are to drive and remove, but if you can source them locally it's got to be cheaper than having an airplane-specific rig sent from the states. And they look stout...

Regarding the orange plastic screws...the problem with using three screws on one anchor is getting the line tension and angles right. If each screw isn't subject to the same force, you really don't have anything more than one screws' holding power. If the cordage angles between the screws and the anchor exceed around 35 degrees then you dramatically increase the torsion on the screw head and neck, which isn't good.

It's certainly possible to string three of them up to one wing, but it would require rigging and knot expertise beyond just running some line back and forth. How well the plastic will hold up is another good question. I've never been that fond of plastic in structural applications.

A single, more massive aluminum anchor seems like a better choice to me.

Equalizing 3 (or more) anchor points is not difficult or hard. And carrying tooling to install 1 massive anchor seems like overkill to me. Seems way easier than rigging 3 wood pickets. But I admit I'm comfortable with the knots.

How to equalize 3 loads with a cordelette:
http://www.chockstone.org/techtips/cordelette.htm

Plastic would wear out over time with dry hardening and UV exposure. Replace every 5 years maybe? I don't know - though they all won't fail at the same time - so having 3 provides a bit of redundancy.

I'm concerned about my abillet aluminum fly-ties. At least every time I use them I inadvertently miss the nail and hit the billet with the hammer. Which I know is VERY bad for aluminum. It does not work harden - microfractures form that you cannot see and they catastrophically break with no warning, unlike steel.

soyAnarchisto wrote:Equalizing 3 (or more) anchor points is not difficult or hard. And carrying tooling to install 1 massive anchor seems like overkill to me. Seems way easier than rigging 3 wood pickets. But I admit I'm comfortable with the knots.

How to equalize 3 loads with a cordelette:
http://www.chockstone.org/techtips/cordelette.htm

Plastic would wear out over time with dry hardening and UV exposure. Replace every 5 years maybe? I don't know - though they all won't fail at the same time - so having 3 provides a bit of redundancy.

I'm concerned about my abillet aluminum fly-ties. At least every time I use them I inadvertently miss the nail and hit the billet with the hammer. Which I know is VERY bad for aluminum. It does not work harden - microfractures form that you cannot see and they catastrophically break with no warning, unlike steel.

Good find on the chockstone page...that's a lot easier than trying to explain it in words. Though that figure-8 knot is going to be arduous to undo if it gets any sort of load. Running a rod through the knot before it gets snugged up can help when it's time to untie. And ya, it's definitely easier than cutting and rigging six pickets, but I rather enjoy that sort of thing, so time and effort aren't part of my personal equation.

The OP mentioned he was dealing with rocky soil, so I don't think plastic would work for him. As for tooling...a socket affixed in the center of a two-foot wooden handle shouldn't weigh much, though it's something you'd have to make yourself. How easy it is to drive a large screw like that without an impact driver, I don't know.

If you replace your aluminum ground anchors, maybe get yourself a good wooden mallet instead of a hammer...I doubt that would cause many micro-fractures. Probably lighter, too.

If you like the orange screws I think you should get a set and try them out! I'd be interested to hear how you like them.

Interesting thread.

Rather than pickets or spikes, why not a 12-18" piece of perforated angle iron? A guy can point the end if desired, but I've never found the need. They hammer in pretty easy and if properly placed they offer good resistance.

mtv wrote:

Easy Riser wrote:I started searching some time ago thinking there had to be something like a duckbill anchor that could be removed fairly easily. This is what I have found and have been using.


The wire is attached to a tang that lines the anchor back up vertically and pulls it back up the hole left by the drive rod. The do work real well. I bought them from the snare shop dot com. They call them bull it point super stakes. These babies hold a lot of pull, I don't have any way of measuring that but I am impressed.
Mike

Good find! Here's a direct link to the page: http://www.snareshop.com/prodinfo.asp?n ... B%20-%20DZ

Have you tried pulling these back out of the ground, and if so, how difficult was it? Duck bills do hold a lot of pull in my experience....I've used them for years as full time outdoor tiedowns.

Thanks,

MTV

MTV,
Yes, I have tried pulling them back out and to be honest it is surprisingly easy. The first time I was all braced up anticipating it being more pressure on my back than I wanted and I nearly fell on my butt they came out so easy. Just last weekend after using them to anchor a large sunshade, I simply put a Phillips screwdriver through the electric fence wire and pulled them right out. The galvanized fence wire is something I just grabbed to give them a try, thinking I might have to use some leverage to pull them and the wire might not do the job, but it was laying around and easy to install. I'm thinking some Hammer custom Amsteel lines might be just what the doctor ordered for retrieval lines but I am still experimenting. Everyone that saw me use these last weekend was asking for the link so they could buy some for themselves. No doubt different conditions are going to change both the holding capacity and the pull needed to retrieve them, so the data continues to be collected.

I apologize for the delayed response, was out all weekend playing like a child. I had to go back to work so I could get rested up!

Zzz wrote:

soyAnarchisto wrote:A removable duckbill with an amsteel line sounds interesting...

There's also these things. Seems better than plain old steel nails and three of them equalized with a bit of cord could be every bit as strong as flyties kit - and a lot lighter weight.



According to their facebook page, they load tested a large orange screw driven in at 45 degree angle at over 640lbs before pulling out. Like a flyties or claw, three of those per anchor (or more) would be hella-strong to hold a plane down.

Those are kinda cool. They are distinct from the doggy-anchors in that they are a true auger with a lot of flat surface area, and not just a helical wire. I'm thinking that must make a huge difference on direct pullout strength.

Like any tiedowns though, the medium they are being screwed into will be important.

I purchased a pair of the Orange Screws this spring, before discovering the removable duckbill type anchors. They are IMHO better than a drive in "nail type anchor" but after trying them in my back yard with my Rans tied down with them, I decided that my trust in them was simply not enough. They work well for tent anchors or something similar that you can keep an eye on but the constant tugging that the gusting winds produce does tend to loosen them up. I pointed these out earlier in one of the tie down threads that Hammer started. There is another company that makes an industrial version of the soil screw type, with models as large is 4 feet long. Not something we could haul with us in our planes though.

Any reason you couldn't use amsteel lines attached to those removable duckbills? Both for the anchor line and the retrieving line would save a lot of weight over swaged steel cable and wire.

How long does that driving rod have to be? Man if you have to carry a 3 foot rod you might as well carry pointed rebar and tie down to that.

soyAnarchisto wrote:Any reason you couldn't use amsteel lines attached to those removable duckbills? Both for the anchor line and the retrieving line would save a lot of weight over swaged steel cable and wire.

How long does that driving rod have to be? Man if you have to carry a 3 foot rod you might as well carry pointed rebar and tie down to that.

I've had problems with amsteel fraying around tight bends with unpolished surfaces.

Perhaps a thimble for the bend then? Or filing/de-burring? A small section of cheap and easily replacable perlon cord (kernmantle) to longer amsteel?

http://www.samsonrope.com/Pages/Thimbles.aspx

soyAnarchisto wrote:How long does that driving rod have to be? Man if you have to carry a 3 foot rod you might as well carry pointed rebar and tie down to that.

Yeah, but you only need to carry ONE duckbill driving rod, versus at least three sections of the pointed rebar, with nine sections providing a lot more tie-down security..

Plus, it sounds like the removable duckbills might be a lot easier to remove than trying to get the rebar back out of the ground... There's a piece of rebar in my yard that I never could get out, so I just dug a hole around it about six inches deep (still couldn't get it out) and drove it as far underground as I could with a small sledge hammer. I suspect I drove it down through a piece of whiterock when I was putting it in the first time... (PS - don't get excited about the holding power - the other three identical pieces came out when my wife pulled them out. She gave me no end of grief about how she got three out, and all I had to do was get one out... Sheesh!)

Battson wrote:Where are guys buying their favourite ground anchors from?

I've been looking around locally, but couldn't find anything at all. I am now planning to buy from the USA.

I want something strong enough to hold down a C180 sized aircraft on a typical dirt / earth surface (i.e. I'm not after ice / snow / gravel anchors - just the normal variety).

Thanks in advance!

Make some! I made 10 sets of these for about 70-80 bucks! Works wonders, just remember to bring a hammer!

http://imgur.com/a/3sitg