The Beta

Discussing the technical background and innovation of SlingFin.

Bombproofing Your Tent Pt1: Windproofing - Wind and Wind Resistance

Bombproofing Your Tent Pt1: Windproofing - Wind and Wind Resistance
Al Tabor - Sunday, November 11, 2018

Windproofing:  How to Secure Your Tent in High Winds - Techniques and Principles.

Worried your tent might collapse in a high wind? Tired of having the top try to flap you to death? Considering extending your range above the tree line and don’t want to buy a whole new shelter?

Here are techniques you can use to harden your tent against high winds (and considerations if you do have to purchase a new tent and want to make sure it can be made resistant to high winds.)

I live in the San Francisco Bay Area...earthquake country!...and have done DIY home retrofitting twice. There’s lots of structural engineering studies on houses. Not so much for tents but, to me, the parallels are obvious and instructive. 

There are two clear first steps to harden your typical California house: anchoring and shear walls. I’m going to look at each of those and translate them into things you can do to harden your tent against the wind. 

Here’s the house version at a glance along with the solutions.


Anchoring

Problem:

If your house isn’t bolted to its foundation, it could just bounce off. If you’ve ever had a free standing tent go free floating, the parallel should be obvious.

Solution:

Stake out your tent with something as tough as the situation. Besides the stakes shown there are specialized cloth snow anchors and sand anchors.

 

Shearing

Problem:

High winds cause the tent structure to distort. This results can be unpleasant as the tent flexes and bobs in the wind or dangerous if the poles break or fabric tears.

(Shearing is the lateral impact of the wind against the resistance of the staked out tent. Now that the tent is solidly anchored, the structure needs to be reinforced against the wind in a way that distributes the stress throughout the structure so as not to lead to points of failure with a tent pole break or fabric tears.)

Solution:

Guy lines!

External guying is a great start. This adds significant stability with little effort. Most quality backpacking tents have external guy loops on the fly to allow you to attach cord and create additional stake out points.

Internal guy lines can take it up to a whole different level. Many mountaineering tents have internal guy points as well. They are rarer in backpacking tents but they’re equivalent of the shear walls pictured in the house above.

 

The stress dynamic might be easier to visual in our (SlingFin’s) instructional video on internal guy lines.

.There’s a critical detail at 1:18 in this video. Note that stress is widely distributed by connecting the internal guy lines to the structure of the tent (both poles and fabric seams are core components of tent resilience) and then connecting that to the external guy lines and ultimately to the anchoring points.


Wind resistance is the result of a system that includes tent architecture, materials, fabrication (in particular the placement of seams), and guy points. Our company, SlingFin, routinely provides internal guying points in all our backpacking tents. Even if you have a tent that lacks them, though, we hope that this explanation of the underlying dynamic of stress resistance can help you find a solution appropriate to your starting point, intended tent usage, and pocket book. If I was trying to jury rig an existing tent, I think I’d start by seeing if I could attach shearing support directly to the poles without having lines touch the tent body (and, hence, provide a path for moisture to wick back into the tent.)

Finally, don't ignore the obvious of location, etc. There's a discussion of those here and here. (I particularly like Ellie Henke's point 5 in the 2nd article.) You can, also, find a detailed discussion of choosing and windproofing a tent on Stack Exchange's Outdoor forum.

Additional elements and who is SlingFin

SlingFin is an employee owned company.

Our ownership structure allows us to maintain our dedication to creating great gear and only bringing it to market if it makes a real contribution.

We love tents. We love challenging design problems.

We began our exploration of tents in high winds a couple of decades ago on Mt Washington (then as employees of Sierra Designs). We set up the tents that could actually be erected in 80+ mph winds (some failed in the starting gate), attached stress gauges, and watched them blow apart. Then we returned and did it again until we had a product that could survive. 

 

Our run as SlingFin took that starting point and began with mountaineering tents and gear for guides. It has now extended down mountain to backpacking tents. Our goal is to have the strongest tent in each weight category. Both our 2Lite and CrossBow (as well as the Portal coming in 2019) have internal guy points. Also, if you use trekking poles, both have a version that allows you to add trekking poles for additional super beefy support.

 

A strong enough wind will, of course, blow down anything...but our mountaineering tents withstand winds that would take apart most houses. We pride ourselves on being the last tent standing!


Copyright SlingFin 2018 under Creative Commons License: okay to use with attribution. Please link to this article if quoting or reusing.