Trick for Tying Down Onto Concrete-embedded Anchors

It is a luxury for me to fly into an airport, proceed to a place to tie down and find permanent tie down anchors embedded into the concrete. That is the positive part of those anchors, but the negative part is that the wells into which the tie down bar is located is often submerged in water (after a rain), filled with dirt/gravel, or full of ice (in winter). Up until I came upon a method I’ll show you I would chip out ice (winter), or dig out the dirt until I could pass the end of my tie down rope through the opening. If submerged, it seems like there is always some stagnant, green, slimy gunk in the hole, making it less than desirable to stick my finger into the depths to see if I can pass a rope.

I recently visited a local REI store (always dangerous) and was walking by the rock climbing displays and saw something that has turned out to work really well…Stoppers. Stoppers are used for placement into cracks/crevices so that they can be wedged to support a great deal of weight. They come in a variety of sizes/ratings, with different shaped aluminum cams/nuts. The stoppers are rated according to the amount of force that would be needed to achieve “failure”. They are rated in kilonewtons, with 1 kN=224 lbs.

The idea is based upon the ease with which one end of the stopper cable can easily be threaded under the tie down bar, minimizing the need to dig deep into the well, and the stopper cable can be flexed so as to slip under the bar permitting the protruding end to be grasped without entering the muck. Slick.

I purchased a 10 kN (2240 lbs) stopper for each of the wing tie downs, and a 7 kN (1574 lbs) stopper for the tail.


I chose to slip a carabiner through both ends and to tie the rope onto the carabiner. With this configuration I keep one end of the tie down rope affixed to the carabiner, tied with a loop knotted with a good old bowline knot.

I simply slide one end of the stopper under the bar, retrieve the end and enter it into the carabiner, as shown. Why the carabiner? I am afraid that the stainless steel cable that comprises the stopper might cut through the rope, and the smooth carabiner pretty much eliminates this possibility.

The carabiner is also rated in kN, with a wide variety of forces available.


Julie likes this arrangement, in that it keeps her fingers less dirty and eliminates the need for her to tie a bowline knot (I tie it up and have no one except myself to blame if it comes loose!).

Here is how it looks complete with my tie down rope:


I inquired of the REI staff as to any concern regarding the direction of forces weakening the cable, due to being wrapped around the permanent tie down bar, and they thought it to be negligible. I chose the 10 kN and 7 kN size because of their length and size of the nut, in addition to their force rating.

I’m not sure about you, but the tie down ropes that are often supplied by the airport are often substandard, and I like to use my own ropes/straps. I think you might like the arrangement I’ve described, and would appreciate any feedback/mods that you might be willing to share.

Randy

Just put the rope loop through the metal tie down and thread the rest of the rope through it.

keeps me out of REI.

Wouldn't a wide gate carabiner have fitted directly onto the tie-down bar? Rather than buy a "stopper" that you aren't actually using why not simply twist a bit of stiff wire on the end of the tie down rope. Use the wire to thread the rope then remove the wire and tie a bowline. Else a home made wire strop would probably be less expensive that REI climbing gear.

It may actually be worth the effort to dig them clear or dry them out. Some of the ones I was tempted to use were almost rusted through. It's always interesting to see these concrete tie downs after they have been pulled out of the ground. Some are not nearly as impressive underground as they appear to be on the surface.

(I had never heard of these being called stoppers before so I had to research the term. They were called "nuts", larger ones were "chock stones", when I was climbing many years ago. )

md11freighter said:

Just put the rope loop through the metal tie down and thread the rest of the rope through it.

keeps me out of REI.

Click to expand...

Sure, but that gets me back to digging the (sometimes really hard packed) stuff out of the tie down. Ice is really a hassle in winter.

frequent_flyer said:

Wouldn't a wide gate carabiner have fitted directly onto the tie-down bar? Rather than buy a "stopper" that you aren't actually using why not simply twist a bit of stiff wire on the end of the tie down rope. Use the wire to thread the rope then remove the wire and tie a bowline. Else a home made wire strop would probably be less expensive that REI climbing gear.

It may actually be worth the effort to dig them clear or dry them out. Some of the ones I was tempted to use were almost rusted through. It's always interesting to see these concrete tie downs after they have been pulled out of the ground. Some are not nearly as impressive underground as they appear to be on the surface.

(I had never heard of these being called stoppers before so I had to research the term. They were called "nuts", larger ones were "chock stones", when I was climbing many years ago. )

Click to expand...

It seems most airports I fly in to have the hard pack problem, and I tried the wide gate carabiner approach, but again the degree of difficulty in getting the carabiner around the tie down bar was more problematic than the small space needed to push the stopper through. For simply submerged wells the carabiner alone works just fine, as you pointed out. Using a wire as a “needle” hasn’t worked well for me, happy to hear it works for you, though.

Thanks!

Randy

I carry a long handled screw driver and a hammer in the winter to deal with ice

Last time I was doing some training in southern Arizona, I reached down into the recessed tie down, and my flight instructor nearly fainted. He pointed out that rattlesnakes, scorpions, and other nasty critters live in those holes. He then demonstrated the wood handled hook that each plane was equipped with….

MTV

Drop the sumped fuel into the holes to discourage occupancy

Gary

It is good to see advice from someone that cuts holes into people. You really have to be ready for what ever happens!!! I would have said just use the carabiner, but I have also had to deal with tight, frozen stuff and a simple wire loop is GREAT! I have sent 1/2 hour trying to find and chip out tie downs at Palmer when I could not get home. A six pack could get most any IA to make up a few of them and if you had a 32 case of MGD you could get your friends in on it too.
DENNY

BC12D-4-85 said:

Drop the sumped fuel into the holes to discourage occupancy

Gary

Click to expand...

Along with a lighted match to ensure the unconvinced critter really leaves.

mvivion said:

Last time I was doing some training in southern Arizona, I reached down into the recessed tie down, and my flight instructor nearly fainted. He pointed out that rattlesnakes, scorpions, and other nasty critters live in those holes. He then demonstrated the wood handled hook that each plane was equipped with….

MTV

Click to expand...

Are you talking about the tie downs where the whole length of chain is down in the hole? I think they have those at Yakima but don't remember seeing them anywhere in Arizona.

frequent_flyer said:

Are you talking about the tie downs where the whole length of chain is down in the hole? I think they have those at Yakima but don't remember seeing them anywhere in Arizona.

Click to expand...

Yes, at the old Williams AFB, now Williams Gateway....former military bases have them.

MTV

Randy,

Thanks for sharing!

At the recommendation some other SC.org members, I added a metal spork to my tie down kit for digging out packed tie downs. This doesn’t help with ice but seemed like an upgrade from using the tie down kit spike or hammer. Plus I got the titanium one because it sounded cooler. Haven’t had a chance to try it yet because all of the tie down rings I’ve used have been clear lately but the theory seems sound!

—Amy


Sent from my iPhone using Tapatalk

mvivion said:

Yes, at the old Williams AFB, now Williams Gateway....former military bases have them.

MTV

Click to expand...

Ok, thanks. Not been to Willie recently and never tied down there.

I carry a garden weed-fork thingy for digging out tie-down holes and have some sewn nylon straps I can use to connect to really bad places. For the tie-downs themselves I only use quality marine dock lines (if you buy good ones 1/2' dia. is more than appropriate and easier to tie a hay-hitch knot in plus they take less of a hole to fish it through) with a spliced loop and synch it around the tie-down bar or loop straps and you're golden. Oh and don't get white tie-down lines, those get really ugly quick. The nylon loops work really well to keep your nice ropes away from tail-wheel grease and are long enough to go around the spring or stinger.

Worst problem I ever had was when looping my good lines to the tie-downs and with the ground water in the recesses on the ramp froze solid on a cold night and all I could find was a coffee cup to carry hot water from the FBO to the far end of the ramp a 1/4 mile a away to thaw them out.

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DENNY, I like your idea of rewarding an interprising A&P for fabricating stainless steel cables for our tie down purposes. I assume some sort of swedging would work well…but you don’t want the thing to ever come loose. While I paid more for the stoppers than I would for materials and reward for the IA, I also have some comfort in the fact that the people who make those stoppers understand that someone’s life is hanging from it…

One of the things I didn’t care for with the stopper is the moveable aluminum thingy (using Kirby’s verbiage here) that sort of gets in the way. I look at it differently now, in that by holding the middle of the cable close together it facilitates threading the loop under the tie down bar.

Randy