16-man Tipi and Line-Loc Failure

[parshal]

I've been using line-loks on all my floorless shelters to get more airflow. I've had them on my SO 16-man for the last few trips without any issues. I had it out this weekend and we had a good burst of wind for about 90 seconds. It could not have been over 30 mph and was probably closer to 25 mph. I use a Kestrel often and also have a Davis weather station at my house and really pay attention to wind.

Anyway, over goes the tipi in the middle of the burst. Three of the line-loks failed. I figure they failed first which then left the tipi without enough stakes. I had about half the ground stakes in use which is still a lot of stakes. When they failed, it bent two of the nail stakes and down it went.

I'm now pretty convinced the line-locs probably aren't a good idea on a shelter as large and tall as a 16 man. I may just have to tie the cordage to the loops and leave the line-locs for the upper guyouts if I ever end up using those.

You can see in the pic that one loc broke in half. The center holding the cordage failed on the other two.

I'm incredibly impressed that the tipi suffered no damage. The fail was strong enough to bend one of those stakes quite a bit. I wouldn't have been surprised to see some tearing around the stakeout loops where they're sewn on the tent. Impressive durability.

 

[Kevin_t]

That was a real wind load . Line locs break at about 110 lbs of force. Of course being pitched up a bit adds a bit more stress vs to the ground.


Thanks
Kevin

 

[parshal]

That's pretty much what I figured. I'd run line-locs on smaller tipis without issue. I know my 12-man had been in similar winds but there were some low trees nearby so it's probable they didn't get the full wind effect like this time.

From your response, I'm guessing line-locs on a shelter this large might be a bad idea. That's my conclusion and will be abandoning them for the ground stakeouts.

 

[Kevin_t]

That's pretty much what I figured. I'd run line-locs on smaller tipis without issue. I know my 12-man had been in similar winds but there were some low trees nearby so it's probable they didn't get the full wind effect like this time.

From your response, I'm guessing line-locs on a shelter this large might be a bad idea. That's my conclusion and will be abandoning them for the ground stakeouts.

Well ... There are things that can be done
1. You could use a slightly smaller cordage that will slip before the line loc
2. You can just tie a loop and taught line hitch and forgo the line loc


However, as you see raising the edges of a 16 man .. a bit of wind and it's a pretty hard core load. Way different than a small trekking pole tent for sure. I would not recommend raising it in any sort of long term wind and as your pretty hard core stakes showed .. there was a lot fo stress there. A better approach may some selective raising of a stake point or two (you can actually tie a stake point up the guy out if desired).

Kevin

 

[parshal]

That wind came out of nowhere. It was dead calm both before and after it.

I'm very impressed that the steel stake bent before any stitching on the tent failed!

 

[Kevin Dill]

I found...through experience...that heavy wind getting under an edge and inside any type of tipi will add enormously to the loads at stake points. Think of the wind getting under an umbrella and you've got it. When gusts hit and fabric is shaking or flapping, the line-locs are being asked to hold up under shock loads which can be quite a bit more than their static load rating.

In any type of hunting setting I always utilize every stake-down point and don't skip any. I use line-locs for auxiliary guy-out cord tensioning only. If I was going with any type of elevated pitch for ventilation I would not trust line-locs. I would eliminate that variable and go with securely tied loop extensions.

 

[MontanaMarine]

I've always just used some 550 cord. I'll cut about 14" or so and tie the ends together forming a loop. Then feed it through a stake loop securing it slip-knot fashion. This gives about 6" of extension.

The other end of the loop goes to the stake. I make at least one full dally around the stake to ensure it doesn't come off. Tension can be added by making a few extra dally's around the top of the stake.

The truckers hitch is another simple method that is pretty stout for longer extensions.

 

[RockChucker30]

LL 3's will break at either the cordage crossbar or the webbing crossbar at between 110 to 120 lbs or so. As Kevin said, moving to a 2mm to 2.5 or 2.75 mm cordage can add some slip, but most of those will slip in the 30-70 lb range, which will save your linelocs but be annoying in wind.

On my 8 I made stake loop extensions that have an overhand loop for the stake, then the cordage runs through the stake loop and finishes with a taut line hitch. Adjustable and strong, but I'm cautious about pitching the whole thing up if I expect much wind.

 

[piercej]

What about some Lawson Bar Tensioners? Made of 6061 T-6 Al so they should be much stronger than the LL3.

 

[parshal]

Those would definitely be strong. Weight wouldn't matter too much, for me, on my 16-man since I'm not packing it.

 

[Dirtydan]

I would caution against using anything with a really high tensile strength like aluminum. You have to remember that our shelters are made of nylon and stitching and in serious exposure something's gotta give. Even 3mm glow wire has a 550lb breaking strength. I'd rather replace a couple dollar piece of hardware than have to deal with a ripped seam or worse a torn shelter panel.

 

[piercej]

I would caution against using anything with a really high tensile strength like aluminum. You have to remember that our shelters are made of nylon and stitching and in serious exposure something's gotta give. Even 3mm glow wire has a 550lb breaking strength. I'd rather replace a couple dollar piece of hardware than have to deal with a ripped seam or worse a torn shelter panel.

How would using those be any different than using a knot?

 

[parshal]

That's what I was thinking, too. However, you'd have the same 'problem' if it's directly staked to the ground. Something has to give somewhere and we don't want it to be the stitching or fabric.

I guess the bigger question is how much 'more load' is taken when a large shelter is pitched higher vs staked directly.

 

[Beendare]

My take on this whole thing....and yeah, I've had my share of heavy winds- had 90 mph gusts snap poles on a Cabalas Guide tent on Kodiak.

My guess is that the shape of your tipi didn't hold. These Tipis shed wind about as good as anything....but the shape must be maintained to do so.

They shrink when it's cold...and then will get concaved from the wind- similar to a sail....my guess is this was your downfall. Of course its going to be worse with a huge tipi like that 16 man.

The fabric and seams can take a lot of tension- get them taught....you have to adjust these regularly

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