am I the only one who thinks that using an ultra-lightweight fabric to build an expedition-grade shelter sounds like a recipe for certain disaster.
Martin Zemitis on Tent Design Essentials and Trade-offs
Martin talks about designing tents for the most extreme conditions as Yvette Fernandez works to make him more comfortable in the lime light.
Jack Gilbert: I think you may be doing an interview with the man who was once described by Outside Magazine as a truant on salary, Mr. Martin Zemitis,.. a designer that really did know what he was doing even though did get some time off to test his products.
Martin Zemitis: In tents the weak link is what destroys a tent and so the idea is you have a certain amount of weight and you have a certain amount of resources and what you want to do is you just want to make sure there no weak links.
One of my pet peeves is people using a webbing that has a 1300 pound tear strength and they sew it to a fabric that has a 5 pound tear strength. It just doesn’t make any sense and that’s where you’re using your resources in an inefficient manner because you’ve got this really heavy webbing and you’ve got this light weight fabric. What you need to do is you need to balance that and then use that extra weight, either save it or use it somewhere else to strengthen up another member that’s not quite as strong.
Yvette Fernandez: Talk to me like the techie. In other words, I’ve heard you talk about the specific things; it’s got to be the right thread, it’s got to be the right zipper, the right looping, the right everything, and I’ve heard you say that it’s this much in diameter and et cetera, tell me about those things.
Martin Zemitis: A good example would be having on a tent, for example, where you have a grommet tab where the end of the pole goes into it, a lot of people will put these nice big, thick heavy webbings on there. And it looks good, it looks durable, the problem is that you’re applying this very heavy material against a very lightweight fabric. And what you do is you end up getting hinging, you end up wearing the edges of the fabric and it actually turns out to be a cause of a possible failure point and it’s actually a weakness to the whole structure. Plus you can take the weight that you have in a grommet tab and you can apply it somewhere else to help make the structure stronger. So having something look durable like a big, heavy grommet tab can actually be a point of weakness.
So the idea is to match the different materials so that you don’t have any stress points. And in addition to that you have to sew it properly, you can’t just put a bar tack on the webbing, you have to sew across it on to the fabric and then this way you keep the hinging down and then you end up having less stress on the fabric and.... Little details like that. Or even the type of webbing, a lot of people use the wrong type of webbing when they attach their fly sheet to the tent body, so when the wind, especially a buffering wind, the fly attachment system ends up loosening up because of the wrong webbing and then the whole product fails. So you can have an expedition tent that doesn’t work at all if it’s got the wrong webbing or it’s not sewn right and so you can’t just call it an expedition tent, you actually have to work all these details out and match the pole diameter, the seam construction materials so you don’t have any weak links.
And the idea is that the whole structure fails all at once and then you’ve sort of succeeded in the sense that you’ve made the strongest possible structure. And imagine trying to build a house that weighs 10 pounds that withstand 120 mile winds, it’s pretty difficult to do. Eventually with enough snow and enough wind the product will collapse. But the idea is that by applying the materials properly you’ll have it last as long as possible.
And with the tensile structure it’s all about the details; the tents, the shock cord, the pole diameter, the tube thickness, the alloy, the yield strength, all those things, every one of those details when it’s very windy and the conditions are very serious, all those little details count. And it’s very easy to try and save money or try to use the wrong stitch or use the wrong stitch length or use fabrics that aren’t calendared properly. It’s very enticing to save a little bit of money here and there but if you want to make a product that really lasts and works when you need it the most, you need to go that extra length and worry about those details.
So one of the things I liked about working in the industry for these high-end brands is that they always wanted to do better and they always wanted to make structure that were – each year they wanted to improve and that sort of set the bar higher and higher over the years so tents got lighter and they got stronger and it benefitted everybody. And considering that’s your house in the mountains that’s very important!
I mean, Phil Scott had a great saying, he said, “the heaviest tent in the world is a lightweight tent that failed.”
---- Outtake -----
YF: Talk to me like the techie. In other words, I’ve heard you talk about the specific things; it’s got to be the right thread, it’s got to be the right zipper, the right looping, the right everything. And I’ve heard you say that it’s this much in diameter and et cetera. Tell me about those things.
MZ: I’ve no clue what you’re talking about!
YF: Yes you do!
am I the only one who thinks
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