MSR has a new tunnel tent – the TindHeim

[Jeff McWilliams]

Sierra Designs also did some wind tunnel tests of some of their tents back around 2015/2016.

[Jerry Adams]

“In my experience, most owners of tunnel tents do not pitch their tents with even 10% of the required tension. This leaves the fabric slack at times…Could the fabric ‘burst’ at these high tensions? Not a chance: it was nowhere near its tear strength.”

Someone posted a link to a website where they claimed a cupped side has bigger aerodynamic drag so it has more wind resistance.

If a tent flaps, then at some moments there’s less tension on the guylines, and other moments more.  Those moments it’s more, the tension will be higher than if it had constant tension all the time.

If there’s a situation where conflicting ideas are opined – tent has to be taut or flexing is better, for example, then that’s when you can really understand the problem.  And, deciding which is “true” isn’t what’s important, it’s the arguments supporting each side.  And then devising experiments to figure it out.

The only failure I can think of was when the center pole on my mid started flexing.  I was using an undersized pole (0.44″) which weighs less and is fine when it’s not very windy.  So, the effective length of the pole was reduced so the sides flapped a lot.  Then (fortunately?) the stakes started pulling out.  I found a pole and re-set up the tent and it was okay after that.  Conclusion – you want the sides to be taut.

[Jerry Adams]

That tent atop the VW on the picture I posted of MSR testing looks a lot like Roger’s tunnel tents

It has three poles

There are guylines at the front and rear to put tension along the length of the tent

Lots of guylines on the sides

But, it’s poles aren’t semicircles, but have straight parts and curved parts

[Jon Solomon]

Is there a debate about whether taut or flexing is better? I don’t think so.

For my part at least, I’ll readily concede that the taut option (small diameter pre-bent carbon poles spaced tightly across the length of the tunnel) is better than the flex option (larger diameter alloy poles spaced wide). Hands down.

But if the taut option has never been brought to market despite the best attempts to do so, there is a reason for that. Hence, the debate is moot.

The point is that the flex option is  feasible in the factory, marketable in the store, and viable in the field. Which the taut option is, alas, not.

But that doesn’t mean the flex option sucks. I wouldn’t hesitate to recommend a Nammatj to anybody willing to carry it, while pointing out that double poling is always an option.

That MSR tunnel is very different from Roger’s tunnel design, starting with the lack of gothic arches. The colorway is pretty funky, too. ;-)

BTW, what would happen if the tent, or more likely parts of it, blew off the back of the truck into somebody’s windshield causing an accident?

[Jon Solomon]

its poles aren’t semicircles, but have straight parts and curved parts

I must be missing that. But they aren’t shaped into a gothic arch.

Edit: yeah, I see what you mean, Jerry.

[Jerry Adams]

“BTW, what would happen if the tent, or more likely parts of it, blew off the back of the truck into somebody’s windshield causing an accident?”

ahhh… the good old days when people didn’t worry about liability law suits : )

I don’t really care if someone states something authoritatively, even if it’s false

I’m more into the ideas expressed and what I can use to do experiments to figure things out

and I’m not into negative energy posts attacking someone else on the web.  Like Elon Musk on Twitter.  Boring.  This site isn’t too bad that way.  I’m sure some of my posts can be taken that way.  (And over-all, I have a positive opinion about Elon.  Very interesting for sure.)

[Jon Solomon]

ahhh… the good old days when people didn’t worry about liability law suits : )

I was thinkin’ the same thing!

[Daryl and Daryl]

Jerry,

Thanks for the photo of the old MSR tent.  A blast from the past for me.

It had an interesting feature.  Marsh mellow sized foam pieces were attached to the inner tent to keep it from touching the fly.

They drove it on the freeway so I assume it was wind resistant to around 70 MPH.

[Jon Solomon]

 Marsh mellow sized foam pieces were attached to the inner tent to keep it from touching the fly.

That was common to other manufacturers, too.

I had a tent that was like that. A Marmot tent, I think.

[Roger Caffin]

But if the taut option has never been brought to market despite the best attempts to do so, there is a reason for that.
Oh, but it has! But not in America. You find them in Australia, New Zealand, and parts of Europe.

But there is a problem with the economics. Every mfr wants to focus on the high-volume and most profitable part of the market. The ‘extremes’ of the market have lower sales and require more attention to keep the products up to quality. Too much like hard work. So in America the mfrs can make good money by focusing on the mass-market side of the game, and the tunnel is not well known. You do see the occasional foray into the extreme end of the market, but it is hard work and the salesmen can’t be bothered.

So why do mfrs in Oz and NZ make tunnels? Because there is market pull: we have some extremes of weather which are not that common in USA. The same for some Euro mfrs, but to some extent the pressure is not as high there. Why so? Because in the Euro Alps they have Refuges all over the mountains providing both accommodation and food. People with tents are rare.

I mentioned the Fliegfix videos. There are here:
https://www.youtube.com/@FliegfixOutdoor/videos
You have to go down a bit, past the canoes, to find them. Some of them are a bit hilarious.

Cheers

[Bruce Tolley]

Hey Roger, Thanks for the link.  The Hilleberg Soulo seems to have survived until the end of the video.  Due to (relative) rigidity, yes? Until the guylines pull the stakes out…

But back to the thread. Occasionally I buy gear from the UK web seller UltraLight Outdoor Gear. They have 77 2 person tents on their web site.  4 or 5 of them are 2 pole tunnels, and the 3 tunnel 2 persons cost more.

Over the years I have seen every now and then an MSR tunnel tent appear which never shows up in the USA. Perhaps to fill a hole in their UK product line since they seems to get customer  traction with their 3 season pop up wedge designs.

When I got a girlfriend who likes backpacking in the mid 1970s, instead of sleeping under the stars I would rented every now and then a tent from the original NorthFace or Sierra Designs stores in Berkeley, Calif. My recollection is that those tents were all some sort of tunnel design.  I am not sure why the North American manufacturers moved away from tunnels. Perhaps California backpackers were not happy managing the condensation. Or maybe, as you posited, the trend toward lower cost designs.

Cheers!

[Nick Gatel]

When I got a girlfriend who likes backpacking in the mid 1970s, instead of sleeping under the stars I would rented every now and then a tent from the original NorthFace or Sierra Designs stores in Berkeley, Calif. My recollection is that those tents were all some sort of tunnel design.  I am not sure why the North American manufacturers moved away from tunnels. Perhaps California backpackers were not happy managing the condensation. Or maybe, as you posited, the trend toward lower cost designs.

Probably due to consumer demand. People want light, easy to set up shelters and the demand probably includes a lot of inexperienced backpackers.

In the ’80s Sierra Designs sold the Super Flash (I still have mine), which is a kind of modified tunnel. The fly kept the poles in place. Weight is 6.2 lb. and requires 20 stakes for extreme weather. Back in the day it was one of the US Antarctic Program’s standard issue tents, along with the North Face VE-25.

Note the Clips to secure the poles to the inner. These were later incorporated into the two-pole Flashlight, renamed, the Clip Flashlight.

 

 

 

I still have my ’70s Sierra Designs Flashlight, and two pole set up, with the poles going through seams in the inner. New models used the clips like the Super Flash. It is 3.5 lb. It work well in light snow. On one trip in blizzard condition I had to get up hourly to knock off the snow accumulation in the area between the two poles, it was too long a span. It is fairly good in moderate winds, but can’t hold a candle to the Super Flash.

 

 

 

[Roger Caffin]

Those high arches do constrain the poles a lot, but the tent design can still be a pig to erect in high winds.
Agree about snow accumulating, especially on flat tops. That is one reason my designs have peaks. Another is (of course) the peaks are good at shedding heavy rain.

Or maybe, as you posited, the trend toward lower cost designs.
People want light, easy to set up shelters and the demand probably includes a lot of inexperienced backpackers.
Yup.
Fair enough: you have to start somewhere. (Me, at age 14 in the Scouts.)

Cheers

[Nick Gatel]

I bought this used REI tent at age 16.

 

 

[jscott]

“people want light, easy to set up tents…” and this is a bad thing? Paging Dan Durston…

No one really wants to go back to those wonderful tents from the past.

I grew up across the lake in Seattle. Kirkland. I got my first tent from the REI store in Seattle in 1972. I had a job doing trail work for a collective that made bids with the Forest Service. That tent kept my dry over a week of ceaseless rains in the Hoh rain forest and elsewhere. It was a cheap model that my mother could afford. I’m sure she was glad to see me out of the house.

I have no idea as to its specs. But for sure, it didn’t weigh six pounds, or four. Well, probably between three and four pounds.

later on, I used to ponder the Flashlight as a possible solo tent, but always ended up with various iterations of the North Face Tadpole, etc.

Middle agers are welcome to read this post to put themselves to sleep.

Anyway, I don’t go out in extreme conditions. Why? I don’t want  to carry the gawdawful weight of a tunnel tent to keep safe.

 

[Roger Caffin]

I don’t want to carry the gawdawful weight of a tunnel tent to keep safe.
Blue 2-man (me and Sue) 3-pole single-skin tunnel tent: 1,342 g, or 671 g per person.
Red 2-man 4-pole double-skin winter tunnel: 2,200 g with serious snow pegs, or 1,100 g/person

Gawdawful?

I dunno , but Sue finds it very satisfactory. (Snow storm outside.)

Cheers

[Jon Solomon]

But if the taut option has never been brought to market despite the best attempts to do so, there is a reason for that.
Oh, but it has! But not in America. You find them in Australia, New Zealand, and parts of Europe.

Whoa, hang on a second there.

The terms “taut” and “flex” were introduced by Jerry as shorthand.

“Taut” in this context refers to Roger’s tent that uses very thin diameter carbon fiber poles pre-bent into a gothic arch and spaced close together and which, when pitched, does not flex in very strong winds. In fact, it couldn’t flex. The CF poles wouldn’t handle it.

“Flex” in this context refers to tunnel tents that use alloy poles in a hoop shape spaced more widely apart and which when pitched in a very strong wind flex quite a bit.

Remember, spacing was a key criteria set by Roger

A span of more than 1,000 mm between poles on the ground is too long. Most of those 2-pole tents have a span of close to 2,000 mm between poles.

The Tindheim is exceptionally large and probably does have such large spacing. Hilleberg 2 pole tunnel tents like the Nammatj and Kaitum, mentioned earlier in this thread, however do not. In fact, there are very few 2 pole tunnel tents with spacing close to 2 meters between the poles. Among the top makers, such as Hilleberg, Nordisk, Fjallraven, Terra Nova, Wilderness Equipment, The Theory Works, Lightwave, Vango, Vaude, Helsport, etc., one would not find such a large spacing.

Of course, both “taut” and “flex” styles are pitched taut, so the terminology is confusing if one doesn’t read closely. The essential point is that the terminological distinction doesn’t have to do with the pitch but with the behavior of the poles in very strong wind.

A tunnel tent that behaves “taut,” i.e., doesn’t flex, in very high winds like Roger’s is not available anywhere, on any continent. All of the ones that are commercially available, such as the Nammatj and the Kaitum, will exhibit enormous flex in very strong wind — even when they are pitched properly taut. This flex, which is part of the design, is what prevents them from catastrophic failure.

 

 

 

[Roger Caffin]

Hi Jon

All of the ones that are commercially available, such as the Nammatj and the Kaitum,
I did mention Australia and New Zealand, didn’t I? The commercially available tunnels in ANZ do use Al poles, are pitched taut, don’t flex, and survive very well. The ones you cite seem to be designed for lower altitudes and forest cover.

This is the granddaddy of them all: the Macpac Olympus. In this case, with a snow loading.
In this case, without the snow.
(Both of these are I think from Macpac staff. My thanks to them.)

And in this case, very high in our Alps and still not flexing. My photo.
The clear area around the tent was partly due to wind in the night, scouring the snow away. Yeah, lots of wind. We slept well. The funny colours are partly due to printing from film, and partly due to the flash.

I will indulge in a small soapbox here. Any tunnel tent which flexes in a storm is either very poorly made OR very poorly pitched. The former is seldom. The latter is, sadly, common – and usually the owners do not even realise their mistake.

Time and again I have emphasised that you MUST put a fair bit of lengthwise tension to a pitching to get optimal performance. If you don’t, you reap the consequences: flapping and possible damage. I have never seen a nylon tunnel tent with fabric damaged by tension.

Cheers

[Nick Gatel]

“people want light, easy to set up tents…” and this is a bad thing? Paging Dan Durston…

No one really wants to go back to those wonderful tents from the past.

Light and easy to set up needs to come after and give priority to staying warm, dry and safe.

Unfortunately in bad weather, structure integrity must take priority, which usually means heavier and more difficult to set up than an UL shelter.

On most trips, unlike many, I don’t use a shelter, so that is zero weight and really easy. I may have a tarp or small mid (less than 12 ounces) in my pack, just in case — usually on longer trips where weather reports can’t be reliable.

Most of the time I’m not going to stay home because of weather. I’ll bring the appropriate shelter for the expected conditions. No, I’m not taking a 6 lb. tent these days either.

 

[Jon Solomon]

I did mention Australia and New Zealand, didn’t I? The commercially available tunnels in ANZ do use Al poles, are pitched taut, don’t flex, and survive very well. The ones you cite seem to be designed for lower altitudes and forest cover.

This is the granddaddy of them all: the Macpac Olympus. In this case, with a snow loading.

I mentioned in another thread just a couple weeks ago that the Macpac Olympus is no longer in production.

As I mentioned in yet a different thread from four years ago, the WE First Arrow is one of the only — probably now THE only — commercially available ANZ 2 person tunnels without vestibule that has three poles. Outside of ANZ,  The Quadratic Tunnel from The Theory Works also fits this description; the Helsport Patagonia is a three person tunnel w/o vestibule that has 3 poles.

What other ANZ tunnel did you have in mind, Roger? You don’t mention any others. Likely cuz there aren’t any others. But if I’ve missed something, please provide a link.

I’d really like to see BPL invite a response from major expedition tunnel tent manufacturers like Hilleberg to Roger’s characterization of them as “designed for lower altitudes and forest cover” and to address the issue about flex in 2-pole tunnel tents.

In this video you can see a 2 pole Nallo 2 flexing in 40 – 60 mph winds.

https://www.youtube.com/watch?v=73KKZDhoj_0

The Nallo is definitely designed for less demanding conditions than the Nammatj on which it was based.

Here is a video of the Nammatj in winds measured at 58 mph (although the guy doing the measurements took them at standing height rather than at tent height). From about 4:13 in the video you can see the tent flexing in the wind. It is also clear that the tent has been properly pitched.

https://www.youtube.com/watch?v=kuaIKL7F_bA

[Ken Larson]

MSR made a tunnel tent – MSR Tindheim 2

https://www.youtube.com/watch?v=2UTmaXq91hI

https://www.elitemountainsupplies.co.uk/camping-trekking-c4/tents-bivi-c15/msr-tents-c63/msr-tindheim-2-person-backpacking-tunnel-tent-p1175

[Jon Solomon]

Clarification: The comments above about 2 person 2 pole tunnel tents “w/o vestibule” refer to tents without a poled vestibule (such as the Nammatj 2 GT). The addition of a poled vestibule adds a third pole but extends the length so that the spacing between poles is generally the same.

[Roger Caffin]

Hi Jon and all

OK, very biased Roger opinions follow. I am sure many will not agree.

1st video: the tent is pitched very poorly. There is very little lengthwise tension in the fabric, and so it is flapping and bellying all over the place. This is BAD. The Nallo is capable of behaving better than this, at least within the limits of a 2-pole tent.

The Nammatj has been pitched better, even though it too is a 2-pole tent. If you look at about 1:25 you will see the abrupt change in behaviour when the camper pulls the lee end out and pegs it down. The windward end becomes better behaved. However, the (black) loops at the windward end corners are far too long and they permit the wind to get under the edge of the vestibule. Some flapping and billowing follows. The loops should be short enough that they hold the edge of the fabric down to the ground.

Even so, there is not enough lengthwise tension in the Nammatj pitch, but it may be difficult to get better unless you replace the lee end loops with heavy (say 4 mm ) bungee cord and stretch that out at least 50%. This does mean the pegs at the ends need to be more substantial the the side guys. In the snow I use deadman anchors.

You can improve the performance further by having ‘sod cloths’ or ‘snow flaps’ all round the windward end. This photo shows what they are:

It helps to pile lumps of ice on the flaps, to keep them down. Soft snow will usually be eroded by the wind in a few hours. Hard ice, or even rocks, are better. Alternately, if it is snowing, just keep knocking the snow off the tent, to rest on the snow flaps around the edges.

Of course, in better weather, we have this (still with high tension):

I have seen claims, by a vendor of pop-up style tents, that the tunnel tent can be blown sideways. Poor spin doctors. Look at the guy ropes above: those poles will not deflect under the sideways wind.

In addition, if the weather is serious, I put up the internal guy ropes. These go horizontally from pole to pole at the height of the upper guy rope attachment points. When the internal guy ropes have been tightened you have a FULLY braced structure. The poles cannot move. This does present a certain inconvenience in that free (human) movement within the tent is now a bit limited: you have to dodge the internal guys. But this beats the hell out of having the tent flapping around your ears all night.

That tent sat there on the ridge in a 100 kph snow storm all night, while we slept happily all night. Unlike the video of the Nammatj, the inner tent was quiet.

Cheers

[Jon Solomon]

Roger, have you tried substituting heavier, thicker poles for a production version? Of course it will increase the weight considerably but it would eliminate a potential customer service nightmare that would give any manufacturer pause. I mean, if someone as experienced as Ryan could break the delicate thin diameter carbon poles because of user error during set up, it’s obvious that those poles are a huge risk in the hamfisted hands of the average user from the great unwashed masses. That’s gotta be a significant obstacle to getting them into production. Ryan said the solo version you made for him weighed 2 lbs. Switching poles might add 1 – 1.5 lbs (His solo tent only had three poles as opposed to the five pole 2P tent you’re showing here). Even at 3.5 lbs it would still be quite light for the protection claimed.

[Roger Caffin]

Hi Jon

Ryan wrote: I have legit fears about the carbon poles in the Caffin tent, because I’ve broken them during setup (my fault). They’ve never broken in a storm – just max out the guyline options and be careful.

[edited – MK] In his own words, the breakage was his fault. IIRC, (which is not guaranteed, the breakage was due to not inserting a pole fully into the ferrule. This is a known risk with my CF poles. But you can also do this with aluminium poles! At one stage I collected a big handful of damaged Al poles from a very friendly gear shop, and a lot of those were damaged this way, at the ends. Customer fault.

For the record, I emphatically do NOT agree that these CF poles are ‘fragile’. I have loaded them heavily on the bench, to measure their deflection. They are STRONG. I have put one down on a flat rock surface and put my full weight on it, to see if I could crush it. I could not.

They are not all that thin either. The are a 2-D wrap construction, which is seriously resistant to splitting. However, they are not the cheapest sort of CF tube you can buy. They are made as arrow shafts, and can handle very rough treatment. You pay a premium for that.

Mind you, be very careful what you buy: some so-called CF arrows which look the same are just pultruded glass fibre with a dusting of graphite powder on the surface. Bend them as for a tent pole, and they immediately split full length. (That cost me.) The pultruded design has no strength sideways.

The proof of the porridge is to be seen in the photos of both the blue and red tents. They have had a lot of use (many years for the blue tent) and under very high winds for the red tent, and the poles show no sign of damage. OK: care is needed – but the same could be said for any very high performance gear. If you want gear for novices, go back to steel pipe and canvas.

It has seemed to me in the past that one is always presented with a conflict over getting something into production. You have to be willing to degenerate and corrupt your design to make it easier to manufacture, cheaper to mfr, and to be able to sell it to the great unwashed masses (who won’t look after it) for peanuts. That is not my game.

Cheers
(Please note: the red tent has four (4) poles, not five.)

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