Sep 25, 2013 at 12:54 pm #1308061
I recently made a tent customized for my own needs, particularly for longer duration hikes in exposed and high wind areas.
The basis of that design was to combine trekking poles with flexible alloy tent poles to work both with and against each other. It seems to work well, so I have taken this principle a stage further and designed another one for more extreme use.
This tent is slightly heavier than the other one, at just over 1 kg, the 2nd pole making the difference. It is slightly smaller inside too, but is going to be used mainly for weekend trips over the winter months.
It is designed again for strong winds, but also with snow loadings in mind. There has been snow on the hills here already this week so hopefully I will get a chance to really test it out soon.
If anyone wants further information feel free to ask.Sep 25, 2013 at 2:08 pm #2028222
Erik GBPL Member
@fox212Locale: THE Bay Area :)
I'm seriously impressed by the design and craftsmanship of this tent and your other, single tent pole design.
Keep up the good work!Sep 25, 2013 at 2:42 pm #2028235
@lunchandynnerLocale: Pacific Northwest
Can't believe how light that tent is considering how burly it looks. Nice work!Sep 25, 2013 at 3:10 pm #2028247
Valerie EBPL Member
@wildtownerLocale: Grand Canyon State
Great idea and beautiful work. An inspiration!Sep 28, 2013 at 3:36 am #2029059
@ant89Locale: North Wales, UK
Looks very good. The colour scheme is very Terra Nova.
Any plans to make these for sale? Or at least drawing up some detailed templates?Sep 28, 2013 at 1:49 pm #2029183
I have had some similar requests, but I want to do more testing on these tents first, especially in winds over 50 mph.
I am still finding improvements that can be made. The 2-pole tent doesn't breathe as well as the single pole tent, for example, and I think it could benefit from a high level vent at the rear of the tent.
I will make up another 2 of these tents in October, which I will give away as samples, as I would like to get other peoples' opinions. If the feedback is positive, I will make these tents available, either through commissioning a short production run, or possibly as a MYOG option.Sep 28, 2013 at 3:07 pm #2029193
Colin KrusorBPL Member
@ckrusorLocale: Northwest US
Marc, as others have said, your designs and fabrication are beautiful. Nice work.Sep 28, 2013 at 5:58 pm #2029218
@fluffinreach-comLocale: no. california
the man asked for opinions .. ohhh kaayyyy ..
i might consider adding a ground-level tape on the door side, so as to take the strain when the door is open and you have everything pulled quite tight.
in that way, the zipper would not be so stressed pulling your act together.
it is indeed, a very nice looking tent.
v.Sep 29, 2013 at 1:15 am #2029274
Bearing in mind that the basic concept of a 'freestanding winter tent' is patently absurd… But this one has guys ropes too.
CheersSep 29, 2013 at 2:29 am #2029278
That is a good idea, thanks.Sep 29, 2013 at 2:36 am #2029279
I agree, I always make use of the guy ropes if I can.
Sometimes I cant though, like the situation in the first photo on the summit. I think I managed to get just 2 stakes a few inches in at the corners of the tent, and with a few rocks 'borrowed' from the summit cairn put on the floor, it was enough to stop it blowing away.Sep 29, 2013 at 9:20 am #2029317
just Justin WhitsonMember
I just want to echo what others already said, nice work, and for a newbie sewer especially–quite impressive. I actually have a hard time believing this was your first sewing project.Sep 29, 2013 at 9:35 am #2029320
Ken T.BPL Member
"Bearing in mind that the basic concept of a 'freestanding winter tent' is patently absurd… But this one has guys ropes too."
Sigh, Roger, what if everyone used self supported instead of freestanding?Sep 29, 2013 at 9:56 am #2029324
To be honest though, I had to do the single pole flysheet twice. On the first attempt, I cut the fabric to follow the arc of the pole, not allowing for the extra stretch that you get when you cut on the fabric bias. I could never get the side panels really taut all over.
Most of the stuff I have learnt about sewing I have got from this forum. Also, some of the things to consider in a design I got from previous articles. My mother taught me how to use a 1956 Singer sewing machine that had an electric motor retro-fitted. It only does 1 stitch, but if you use a crossed box pattern for tie-outs, that seems to be all that is needed.Sep 29, 2013 at 1:48 pm #2029366
> Sigh, Roger, what if everyone used self supported instead of freestanding?
The exact words do not matter. You will notice that Marc wrote 'I agree, I always make use of the guy ropes if I can.' When the wind is strong enough, poles by themselves are just not strong enough.
The term 'free-standing' is a bit of marketing spin. The problem with using such terms is that novices may believe in them, and then find themselves in an unfortunate situation where their gear fails completely, imperilling their lives.
CheersSep 29, 2013 at 3:55 pm #2029390
"Freestanding winter/summit tent" was probably not the best way to describe this tent, I am not trying to suggest that it can be used in the winter or on summits without the guy ropes.
My understanding is that if you have a strong pole structure that is self supporting and the panels are tight, then the guy ropes are really only doing one job, acting against wind loads. Some tents require a high degree of tension in the guy ropes to be pitched right, even before taking wind loads into account, so there may be more strain in their guy ropes/stakes, all other things being equal.
That is the only real advantage I see to the self supporting type, you might be able to get away with less stakes in the ground, or alternatively, the stakes are less likely to get pulled under the same wind loads. Obviously this is a bit of a generalisation, as there are many other factors that determine the loads on the guy ropes/stakes in a design.Sep 29, 2013 at 5:47 pm #2029406
Sam FarringtonBPL Member
@scfhomeLocale: Chocorua NH, USA
The posts on the Gear spot often make me think of lives in peril. There was also an article here – sorry I forget the title – about several days in late autumn with minimal gear. At least the author was honest about some of the guys wet and shivering all night – fortunately they were young enough to survive it.
Many of the posts appear to have a marketing component that raises concerns similar to yours. But marketers are free to post here, and I wouldn't have it any other way. I think we just have to rely on you as editor, and others who are more experienced, to point out some of the more obvious fallacies. To bad it has to happen like Groundhog Day (that's a Hollywood movie about the same day happening over and over again).
And accounts of unexpected extreme conditions, as in your "When Things Go Wrong" article are helpful also. Let some imagine dealing with that in their dream 12 ounce shelter. But I guess you actually have to be there in the soup to get the whole picture.
Terminology aside, I like having some kind of a framework over me when the weather gets really nasty. Now that I've finally found stronger carbon shafts, it seems a framework can be fairly light as well. And if you're going to have a framework, it might as well support the canopy.
Keep tramping.Sep 29, 2013 at 8:35 pm #2029439
Matt DirksenBPL Member
@namelesswayLocale: Mid Atlantic
When the tent has enough inherent (freestanding) structure, then there is a greater potential of lateral forces (wind) to be resisted by compressive forces of the structure, and not just by the tension of the guy lines…
Or at least I think that's what you are trying to achieve, right?
:)Sep 29, 2013 at 10:19 pm #2029461
I've been hammocking for the past several years, and thus haven't been using a tent. I recently moved into the mountains though, and have been hiking above tree-line quite often, so I've decided to switch back to a tent. This looks just like the tent I've been envisioning in my head. Is their any chance you could post the plans or patterns for the community? Thanks,
–Chris S.Sep 29, 2013 at 11:55 pm #2029467
> When the tent has enough inherent (freestanding) structure, then there is a greater
> potential of lateral forces (wind) to be resisted by compressive forces of the
> structure, and not just by the tension of the guy lines…
Forgive me if I disagree for rather basic technical reasons, but the problem lies initially in just one word. That word is however vital. It's 'compressive'.
The only things in a tent which has any compressive strength are the poles (CF or Al). They have way more than enough compressive strength, so that is not an issue.
The poles also have flexure (bending) strength. In general this is not enough to keep the tent up in any decent wind. Why? Because the large sail-like areas of the fly pull on the poles and bend them, to the point where the poles can bend and collapse.
So what keeps the poles in their right shape? Well, with some tents, not very much. Those are the tents which I tend to dismiss as being useless in a wind: I am sure you all know what general classes I mean. Any tent with a throw-over fly falls into this class. Any tent with l-o-n-g unsupported poles does so too.
However, there are tents where the poles are held in shape by two forces. When the pole is short and bent it tends to be a bit stiffer against further deflection than the long ones arching over a pop-up. This is pole strength, albeit not enough in itself. When the pole is sleeved into the fly and the fly is properly guyed, the tensile strength of the fabric of the fly restrains the pole from bending in 'unfortunate' directions. You have to prevent the fly from distorting too much of course, and that is the main purpose of the guy ropes. When the fly is tight and guyed, the poles find it very hard to deflect. So the poles stay up, and so the fly stays up, and so the occupant has a good night.
I apologise if this sounds pedantic. But reread it at 2 am in a howling gale and see what you think.
CheersSep 30, 2013 at 12:26 am #2029469
Ivo VanmontfortBPL Member
What fabric have you used for the sleeve?
It looks different from the flysheet.
Have you used the seam Roger Caffin suggests for tunnel tents (and the tent pole sleeve design connection to the flysheet)?
Most (but not all) of the pictures of the diagrammatic cross-section’s are removed from the web.
Right at this moment I am busy with making a wooden frame for a tent (soulo hilleberg style)
A lot of questions …will make a new topic about tent clips versus tent poles and its implementation
I think it’s almost impossible to give a pattern because not all lines are straight some are curved.
http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=46644Sep 30, 2013 at 4:15 am #2029474
Matt DirksenBPL Member
@namelesswayLocale: Mid Atlantic
Thank you, Roger.
In my architect's imagination, I was seeing numerous poles transferring their "compressive" energy into the ground below them, like lots of little point loads. (Insert architect joke here…)
But I thoroughly understand what you speak of and will gladly enjoy re-reading it the next time I'm out in a gale at 2am. That would be a much better place to be than where I am right now…
:)Sep 30, 2013 at 4:25 am #2029475
"When the tent has enough inherent (freestanding) structure, then there is a greater potential of lateral forces (wind) to be resisted by compressive forces of the structure, and not just by the tension of the guy lines…"
This was not my intention. I would say this is only true when the wind is coming from the rear of the tent, the 2 alloy poles act like compressed springs to resist the wind forces.
My primary aim was to achieve a fairly rigid pole structure that doesn't distort in strong winds and have fabric panels flapping about. I hate that feeling of being stuck in a plastic bag that has been caught in a tree, it doesn't make for a good nights sleep.
A secondary aim was to reduce the reliance on stakes if possible. I often struggle to find a site where I can get 6 or 8 stakes securely in the ground. I don't think lightweight pole structures in themselves are capable of resisting wind forces, it would take quite a lot of poles crossing each other many times and with small fabric panels to achieve this, but then the weight goes up.
What I am finding is that this tent is placing less load on the stakes than previous tents I have used. I don't have scientific data to validate this, but I have never had to get up in the night and re-set a stake with this tent, which was a frequent occurrence with other tents. Wind loads aside, it is not placing any loads on the stakes, unlike for example, a pyramid type tent that needs to be tensioned onto the stakes just to stand.
In this video (http://youtu.be/PHBAtmQyDFo) the tent is being hit by winds in the 30 – 40mph range directly side on from the right. The frame itself doesn't move out of position, but the lower part of the right pole below the cross over point is getting slightly pushed in. Without the guy line there, it might fail at the joint.Sep 30, 2013 at 4:51 am #2029477
I would love to try hammock camping, but the Scottish Highlands just isn't the place for it.
Tent plans here:
Unfortunately, when I made these tents, I didn't make templates. I had no idea if they would even work. I will be making another sample of each tent in October though, incorporating some minor improvements. I will take notes and make templates as I do them.Sep 30, 2013 at 5:16 am #2029479
The sleeves use the same PU coated 40D nylon that I use for the floors. I think they will be less sticky in frosts than silnylon sleeves, but have yet to test this.
I can't seem to find Roger's seam that you referred to. I have used flat felled seams throughout, where the 2 edges overlap each other twice, and have 2 rows of stitching going through 4 layers of fabric. I believe this is the way Hilleberg do them.
For the sleeves, I cut a length of fabric 100mm wide, fold it in half, and run a line of stitches 5mm in from the cut edges. This edge of the sleeve is then inserted 10mm into the top fold of the flat felled seam and pinned. I then sew the seam so that there are 2 rows of stitches going through the panels and the sleeve, so that the stitches are going through 6 layers of fabric.
There may well be better ways of doing this, I have not had any problems with the seams this way though.
I initially used full length sleeves for the poles in this design. I found in strong winds, the sleeves at the top of the tent were catching the wind and putting a strain on the poles at this point, so I changed to the clips, which work far better.
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