Episode 69 | Ultralight Shelters in Inclement Weather

One question I have specifically for everyone: what’s your storm “kit” for stakes and guylines with the shelters you are using? I’m curious to know how much weight you are adding to your shelter package with stakes and guylines. For most of the trekking pole and pyramid shelters I’m using, I’m bringing about +4 oz of stakes & guylines for extreme conditions.

For my kit, about 7.5oz.  8 MSR groundhogs ~4.5oz and 48′ of MSR reflective utility cord ~3oz.

I bought two 50 ft bundles of Paria Dyneema Guyline to replace guylines in my Lanshan 2 Pro tent, so that with longer guylines I have more flexibility. Here you can see how that tent is pitched.

It has 4 corners, plus 2 ground level tie-outs on the two doors, plus 2 additional ground level tie-outs on the head and feet panels, for a total of 8 ground level tie-out points. I would use a length of 5 feet for those points.

There are 4 other cords at the corners, though. Lanshan refer to them  as positioning cords. They are attached to the bathtub (not the flysheet), and their main function seems to help in positioning corner stakes for a standard pitch. So I don’t know whether I should put longer cords there as well, in order to have more flexibility at staking the buthtub corners as well. Is it really needed to stake the bathtub?

Then there are apexes, and I would use 10 feet guylines.

Finally, for the two mid-height tie-outs at the head and feet panels, I would use 7 feet guylines.

Do you think it’s ok? What are your suggestions regarding the 4 guylines at the corners of the bathtub?

Thanks!

Thanks, Ryan, for putting the emphasis on stormworthiness. This is a subject that I feel really passionate about.

If you were to do a follow up or care to weigh in now, I would really love to hear about how shelter shape affects wind resistance. This is an aspect of structure that you didn’t have time for in this podcast. Rectangles, hexagons, octagons… One upright pole, one hooped pole, two upright poles, two hooped poles… Lots of different configurations.

I’d love to see either quantitative or experiential data on how much of a difference shape makes. So far I think that a small octagonal mid is in a different class altogether from any other UL shelter in terms of wind resistance (even more so when used with peak guylines and 1/3 way up guylines and an inverted V poleset) but I don’t have very much data yet to substantiate and quantify that claim much less compare it to shelters of other shapes in the same conditions.

Thanks, Geoff.
The tradoffs list at the end of your post is a very helpful summary, esp in written form.

I myself have personal experience with all of the shelters that you mention: the Akto, the Soulo, the Paratarp, rectangular mids, the Trailstar, and of course a small octagonal mid.
Since I was soliciting the input of others, I didn’t want to put my experience up front.

Personally, I already have an answer to my question and the small octagon is it. Of the three that I currently have, the two made in sil/sil fabrics (one in 30D silpoly, the other in 10D silnylon, both double coated on both sides, no PU) are really easy to set up with a little practice. The elasticity of the fabric helps. The third, in DCF, is a little more finnicky due to the lack of elasticity in the fabric. Color coded webbing on the perimeter helps, too. The only thing that is a little bit fiddly is the inverted V pole but that’s not necessary to pitch it, either. True, 8 perimeter stakes can seem like a lot but in anything up to Beaufort 5 (22 mph) it doesn’t even begin to ask for guylines — which are, I think so far, not needed until winds move upwards of 35 mph, a point at which most rectangular single and dual trekking pole shelters are already flapping around quite a bit even with guylines deployed. As I said above, the wind resistance of these octagonal shelters is in a class of its own for solo-sized UL mids. Given just how well this works, I’m kind of surprised that there aren’t really any options on the UL market except for a custom order from Xavier at Tipik Tentes in France — he and I worked on the design together so he now has the plans all drawn up and buyers would not have to pay the additional fees for custom design work, but even so the price is about double what you’d expect to pay for a rectangular sil mid from a top cottage manufacturer.

In terms of living space, it’s a palace for me at 5’7″ (170cm). I don’t think it would work for people above 180 – 185cm. The ones I use have a long diagonal of 270cm and a height of 135cm (which I usually pitch higher at 140 – 145cm).  The 10D one weighs 373g. The 30D one, which has double doors and perimeter netting, weighs 600g. The version in DCF weighs 410. Sizing it large enough to accommodate a really tall individual would incur a substantial weight penalty. Small octagons are best for shorter people, or, larger ones for groups of three or more.

Ryan would probably love one.

PS – the alternative design concept is the late-lamented Seek Outside Silvertip.

In stable weather you pitch it quickly as a hex.

But there is a clever guying arrangement in the middle of each panel hem that enables you to turn it into a dodecagon – a very wind-shedding shape that’s virtually round. Although there’s no seam for these mid-point pegs, the design ensures high tension.

It also allows the option of a slightly asymmetrical design that gives a bit more room at the head and foot.

How do you think the concept stacks up against the pure octagon?

https://seekoutside.com/blog/the-bt2-and-the-silvertip-explained/

https://bedrockandparadox.com/2015/03/30/the-mid-ive-been-looking-for/

Hello Geoff,

Sounds like we have similar expectations from shelters.

I don’t think that the solo Octagon is a solution to silnylon in your face but entry is far easier than with the TS. Storm resistance is better, too, not just because of the eight sided shape but also because it extends all the way to ground when desired.

I haven’t used a nest (an “inner tent”) with these octagonal mids. Haitao, the originator of the design that I worked with, used to make nests but since he left the building last year there’s no readily available source.

The First Snow, a hexagonal design with two doors and two vents, uses the same clever principle that you describe for the old SO Silvertip. I never tried the Silvertip but I am familiar with the principle.

There are a couple of designs on Aliexpress that use the same idea of mid panel perimeter tieouts to create a geometry with more panels than geometrical sides. For a brief time the Asta Gear First Snow (Xinxue) was manufactured in Korean 30D silnylon, a legendary fabric that is probably the best on the market. When the First Snow was offered in this fabric, I was very interested in getting hold of one but alas I was too late and just missed out. The current version of the First Snow is made with a sil/sil-pu 20D fabric that is too elastic and yet brittle at the same time; it doesn’t excite me but the price is certainly right. Another tent that uses mid panel perimeter tieouts to the same effect is the Aricxi Walker 2. Like the First Snow, it too is currently made in a 20D sil/sil-pu fabric that is very economical but doesn’t really play to the strengths of the design. The First Snow has ten perimeter stake points (the other two are impossible cause of the double doors) and even has vertical seams from each tieout point, including those that are mid-panel. These extra seams increase the weight but effectively create a double panel on each side of the hexagon. If the hexagonal First Snow were available in a top shelf sil/sil fabric, I would be very interested in that. Fabric choice is just as important as geometry. The 30D silpoly from ExtremTextil is a pretty ideal fabric in the sense that it is elastic but not stretchy like silnylon. It has excellent water resistance, very respectable tear strength, and weighs about the same as the 20D silnylon that MLD currently uses. In terms of wind resistance, a First Snow made in that 30D silpoly of in 30D Korean silnylon probably wouldn’t quite be the equal of the true octagon in the same fabric. The regularity of a true seam is an advantage for the even distribution of wind shear and the uniformity of the panel is better for avoiding deformation. But it would still be a heckuva lot more stable than a rectangular mid and the hexagonal geometry is more livable.

I have an asymmetrical ocatgonal mid made by Xavier, the model that he calls the Aston. The asymmetrical shape makes the space inside more livable as you say. The price though is that the asym design cuts into the wind resistance, esp in situations where wind direction is variable.

On the symmetrical octagon that I designed with Xavier, there are four apex tieouts in addition to the regular mid panel tieouts about 1/3 the way up each vertical seam. The addition of these tieouts gives the option of using two guylines on opposite sides of the mid for enhanced stability in really nasty situations. I’ve not had occasion to use these yet. I’ve had the version in 0.8 DCF made by Haitao, which doesn’t have those tieout points on it, and it stood up without budging to some severe hailstorms in the Pyrenees.

No, the perimeter bug netting (made in 0.7 monolite) doesn’t keep all of the flying critters out. Generally speaking, some will always gain access when opening and closing the door. There is enough airflow to keep the silpoly door open, leaving the monolite inner door zipped out, to help make cooking inside more pleasant.

Making the monolite skirt removable would add weight. Using one of the heavier, denser weaves would probably work as a snow skirt, adding weight but removing complexity.

As I mentioned in the other thread, sometimes I use the octamid with a Wind Bivy from Yama Gear. I don’t feel trapped at all inside that bivy. The 3 zip design makes it easy to open up one side so that you can preserve the structure and sit up. The only drawback for me is that, at 213.4 cm, it is just a tad too long for the octagonal geometry. It would fit better if it were 200cm. I don’t need the extra length. The Y zip design of the bug bivy has a vertical-ish wall at the head.

The line and clip on the base of front door is essential to preserve perimeter tension when the door is unzipped. It works surprisingly well. Here are a couple of photos that show it.
As you can see, it is a 2mm cord that feeds an adjustable clip. Easy to deploy, easy to unclip, though there’s really no need to unclip it. You can also see in the second photo a clip at the base of the door. This is necessary. Haitao didn’t use it on his DCF versions and they suffered for it. You can also barely see on the right hand side one of the color coded perimeter webbing tieouts. It is useful to use red to distinguish one of the two rectangles that form the base of the octagon. This speeds setup immensely.

For the poles, I haven’t used Pacer Poles so I don’t have any experience there.
Of course, the mid can be set up using a single pole, but I prefer using two poles in an inverted V for better livability and unbeatable stability. The inverted V allows one to keep the poles out of the sweet spot along the long diagonal of the octagon, leaving that space free for sleeping, which is how it works best.

The two versions that Xavier made for me were sewn with all of the seams against the bias making it as strong as possible but requiring more fabric.

If you haven’t had it in hand yet I think that you will be duly impressed by the 30D silpoly from ET. It’s a beast of a fabric, a totally different animal than most of the 20D silpolys around (excluding the new 20D silpoly used by Tarptent, which I haven’t seen and which is pure sil/sil on both sides with no PU mixed in). A small bonus: The dark green is really an ideal color for most environments in temperate climates.

A 1P A frame is quite good. Small A frames usually have a low profile and a small footprint. I wouldn’t hesitate to feel confident using them above treeline. Let’s see, I’ve used the Stealth 1 in DCF, the original Tarptent in 30D silnylon, the Gossamer Gear Spinnshelter in spinnaker silnylon, and some A frames from the 70s that I don’t remember. The Stealth was the most impressive. Reliable, the small A frames are, however, noisier than Octagonal mids. The Yama Cirraform looks cool. I hope that Gen will be able to initiate production again.

FWIW, a final comment: The octagon is always much easier to pitch, especially in a storm, than the Trailstar but never as much fun or as satisfying to pitch in good weather.

I’d love to see pics of your shelter when finished. Happy Trails!

Jon

I agree that in theory at least a tipi will be quieter than an A-frame. But I don’t think that any of the current commercial options have optimal arrangements for supporting the big side panels.

The possible exception is this rigging on the old Kifaru Paratarp – which may be good enough to do the job. It is certainly lightweight and simple, and you can take if off if it’s not in use.

Alternatively I may go the extra yard and implement the kind of winged panel support we used in the ’60s – but I’ll start with the Kifaru system.

Thanks for the detail on the ET silpoly – I’ve heard good things about it, but it’s good to hear from someone who has actually used it. It really does seem like the best shelter fabric on the MYOG market if you need something low stretch, affordable and reasonably robust.

Hi Roger

I know that you regard A-frames as children’s toys suitable only for the back garden :-)

But the fact is that the Kifaru Paratarp and Supertarp were specifically developed for use as hot tents. They have been used extensively by hunters in the US winter and do just fine.

Their main weakness is that they appear to use a poor-quality silnylon that sags horribly in the cold and damp. I’ll be using a quality silpoly that will hold its shape much better.

Here’s a link to a recent series of impressive blogposts by Geoff Fisher and Helen McKerral, who deal with the subject of “Tents in Strong Winds” in a 3-part series on their blog, Slower Hiking. Part 3 hasn’t been published yet but Parts One and Two provide easy to understand explanations of principles, suggestions for practical techniques, numerous illustrative links, and copious citations from UL shelter designers.

https://slowerhiking.com/shelter/tents-in-strong-wind-what-you-need-to-know

I’m just a little surprised that they don’t mention hexagonal and octagonal mids, but that’s really a trifling detail.

Well, the Macpac model they own is a dome design instead of the famous Olympus tunnel (now out of production). You’re probably right that they haven’t used tunnels much if at all.

To their credit, though, they do make a point of discussing the importance of elements such as site selection, terrain, wind force, shelter construction, and pitching techniques, as well as the interaction among these elements. I think a lot of people could benefit from that discussion. Unfortunately, since the link is buried in this thread, it won’t get the visibility it deserves. BPL could invite them to repost here or make a link to the article. Personally, I feel that wind resistance is THE overlooked element of discussions about storm resistance in general, so it’s very satisfying to see a focus on the issue.

The only thing that really made me shake my head so far was their choice of a Zpacks Duplex. That shelter is the poster child for poor design for DCF. Dan Durston really nailed it. But again, there is at least some mitigating mention of DCF’s ugly secret — its weakness for permanent deformation.