How hard is it to make a tunnel tent like the one in the photo.

It ain't easy.

Cheers

msr

I converted the link to a tiny url. Let’s see if it works.

The foam pieces were attached to the tent fabric and kept the fly from touching the tent fabric. They maintained an air gap between tent and fly of about an inch if I recall correctly. A box construction sleeping bag baffle technique could do the same thing in theory I guess but I think it would be a challenge to get everything to hang right, especially if you wanted to maintain a uniform 1″ gap between tent and fly. I envision the tent and fly fabric tending to stick together when wet and creating condensation spots. Perhaps a bigger distance between tent and fly fabric would make it easier to create?

I watched this tent evolve at MSR in Seattle in the 70s. I agree with Roger…..not easy. Also, it was very heavy by today’s standards so you’d have to rethink every aspect of it to keep it light.

To advertise the wind worthiness of this tent Larry Penberthy (father of MSR) fastened it to the top of a truck and drove it down Seattle’s newly opened I-5 Freeway.

What are the advantages of such construction?

The big advantage overall with this tent was wind resistance and sturdiness.

Linking the tent and fly fabrics made for a simple-to-erect, one piece, bomb proof shelter.

The foam spacers probably helped with tent/fly condensation problems that were common at the time when the two fabrics would stretch and touch during wet weather.

It evidently didn't sell well, however, so the advantageous didn't outweigh the disadvantages. Larry Penberthy was a pioneer in the field and didn't mind developing things even if he didn't make money. He told me one time he wasn't making any money on the ice axe he developed and sold, for example. He wanted to get people to use them instead of the unpredictable wooden shafted ones to save lives.

Fast forward to present time. Roger is probably one of, if not thee, world expert on tunnel tents so don't pay too much attention to my blathering.

Wasn't this fairly revolutionary leading to a bunch of other tunnel/tube tent designs? So, this is more of an evolutionary step than a useful product for today. This is more rugged than most people need, so over weight.

The outer fly occasionally touching the inner isn't that big a deal so you don't really need the styrofoam spacers.

I have one of those Larry Penberthy ice axes. I thought it worked quite well, but haven't used it for years. I should get rid of it : )

A good example of tunnel tent design was called the Omnipotent by the old Early Winters company. I slept in one in 1979, and it seemed heavy but bombproof.

–B.G.–

> This is more rugged than most people need, so over weight.
That says more about where YOU camp in wintertime and the prevailing weather there than anything else. Yeah, deep in the sheltered pine forests you could probably tarp a lot of the time.

Cheers

I look at weather reports and go when the weather is better

If the weather is worse, I use the "hike high, camp low" prinicipal and camp in sheltered location

Still, the weather reports are only so good and it's hard to get a stretch of several days in a row, so camping in somewhat bad weather is sometimes unavoidable.

If I was climbing Mt Rainier in the winter, as an extreme example, then I'de want the most robust tent possible even if it weighed 5 pounds. That MSR tent would be good.

I can find 5 or 6 days in a row, even in the winter in Oregon, Washington and Northern California that aren't too bad. My sub 1 pound mid is perfect.

What's funny is someone will take a tent for climbing McKinley or Everest, and then advertise that if the tent can withstand this, it should be good for you. No, it's overly built and overweight for moderate conditions…

Like Roger says, making a good tunnel tent ain't easy (and he ought to know, as tunnel tents are the core of his oeuvre).
As to the spacer idea and its validity, I have my doubts. Better, methinks, to simply have a little larger space between inner and outer (and a good tight pitch on the outer) to ensure non-contact. That has the side benefit of better ventilation as well.
As an original subscriber to Backpacker magazine I remember those early review articles. Vastly different from the regurgitated manufacturer's drivel that BP now calls reviews.
And BTW, the Omnipotent that Bob mentions is also reviewed in the same article.

Thanks to Daryl and Daryl for posting the tiny url. A picture is worth a thousand words. The MSR was a fascinating design because if you look at Roger's tunnel tent and back at the photo of the MSR you have distinct similar designs except Roger's looks a little taller to sit up in. Later on the MSR was reviewed again when they tweaked the design and put Goretex for the vestibule ends. It decreased the rating because the Gore Tex would ice up in the cold and the frost would drop into the tent and melt all over the tent floor. I am glad someone mentioned the Omnipotent because it was a double wall using a mesh baffle if I remember to keep separation for the two walls. The other unique tent not mentioned here, but mentioned in the Backpacker Magazine article,and it was not a tunnel tent, was the Rivendell Bombshelter, which lived up to its name when on a high mountain it survived a severe blizzard where the Omnipotent pitched with it was shredded. The Rivendell was an A frame with ridge pole.

I love threads like these. They intoduce history and open paths of research and reading I otherwise would not have known to pursue.

Thanks.

PS: Curious if Roger has ever incorporated a lightweight ridge pole into a tunnel as these old A frames seemed to like to do to eliminate end guy lines and stakes. … and what is a "cooking hole"?

The cook hole was a half moon shaped zippered panel in the floor you could zip out and put a stove inside the tent (highly dangerous)by the way, they often leaked water through the zip and most high altitude mountaineers said they used them as "relief holes" where they could go #1 and #2 if they dug out enough snow so they didn't have to do it outside. Sort of an indoor privy you could say. The cook hole idea was eliminated because using a white gas stove inside a tent without proper ventilation and the way they had the habit of uncontrollable flame when first lit, it was a real gamble not to burn down the tent or if it was not properly ventilated you could die from carbon monoxide poisoning I have a North Face St. Elias with cook hole, snow tunnel door, and of course the cotton frost liner that attached with velcro. The St. Elias has snow flaps also which I have not seen on modern tents that I recall. It is a double A-Frame tent and it is also listed in the same article with the MSR. The old MSR tent in this thread had snow flaps that you can see in the photo.

cookholes also went away because while handy in the snow they leaked like crazy if used in the rain and you got rain running under your floor. So okay on a dedicated snow tent but bad otherwise. Also, vestibules came into use and a vestibule is a far better place to cook.

> Curious if Roger has ever incorporated a lightweight ridge pole into a tunnel
No, because it is pretty much useless. You need the lengthwise tension in the fabric to make the tent perform to its max. The idea of eliminating the end stakes and guys is just stupid in a storm.

Spacing between inner and outer: yes, that's important. I used 50 mm at first but the inner could stick (freeze) to the outer. I now use 70 mm, and that works just fine.

Vestibules are FAR better than 'cooking holes': room for gear, packs, shoes, even indoor toilets (in the snow) in extreme conditions.

Headroom: it matters when you are out for a week. And you CAN have enough headroom and still have the tent take 100 kph winds – proof by example.

Cheers

>A good example of tunnel tent design was called the Omnipotent by the old Early Winters >company. I slept in one in 1979, and it seemed heavy but bombproof.

I owned one. I was bombproof (field tested more than once!) As for heavy, by today's standards yes, based on what else was available, really not to bad. A lot of equivalent (in terms of weather performance) tents were far heavier, and not a lot that was significantly lighter at the time, especially mountaineering tents. The tent served me well for many years of skiing, climbing, backpacking and cycle touring.

I hate to think what it would cost to produce one today, it was not an easy tent to manufacture.

OP – Thanks for posting BP issue #9. Kemsley's soft cover gear guide was good, but not so much as the original reviews in the issues of BP. (Thanks for the history, Daryl.)

Assuming your QN is not just rhetorical and for fun, here's some info:
1. In the past, Roger was willing to provide plans for his tunnels for personal use only. Maybe still?
2. Roger's seam design for the outer pole sleeves is on BPL.
3. http://bushwalkingnsw.org.au/clubsites/FAQ/DIY_RNCTents.htm
is the longer version of Roger's "It ain't easy."
4. A La our Sec of State, I was going to try a tunnel this winter before I decided not to. During that belated thought process, the idea came to build the inner tent as follows:
a. Build the outer first with small lace loops under the pole sleeves where you want to connect the inner.
b. Pitch the outer taut, and hang mitten hooks or the connector of your choice from each loop. (Nite-Ize now makes some plastic mini double biners that are pretty light)
c. Run light cord through the small loop end of the mitten hooks both lengthwise and crosswise, and tighten to create the shape of the inner under the outer. Take the dimensions of the inner from the cord, subtracting a little so the inner will be taut, as the loop connecting the mitten hook to the inner will add some slack.)
d. To insure a taut inner, maybe instead of hook, some small half inch buckle and tape connections at the base of each pole to tighten the inner.
5. That should provide the dimensions to make the pieces for a taut inner tent.
6. Re: The Dreaded Sag – For the outer – See recent MYOG thread about coated 1.1 oz polyester from Ripstop by the Roll, which one poster actually weighed at around 1.2 oz/sq/yd – pretty light. Of if you doubt the WP of the light silcoat, as I did, get ahold of some of the polyester Epic Malibu that was used on the Black Diamond tents. OWF has it off and on, but it is heavier – around 1.8-1.9 oz/sq/yd. But it is pretty durable and was popular with mountaineers. Snow Peak makes coated light polyester for flies used in its products in Japan – so it is out there.
7. For the inner – Lots of choices, and there was a recent post about a good fabric from Extrem Textil for this.
8. For hooped carbon poles, I've blabbed on so many posts on that I don't want to draw slung tomatoes.
Just some thoughts if you are really going to go for it!

Well as Roger says, "It ain't easy" Reading the posts have made me realize that it is too difficult a task. The final nail in the coffin was reading Byron Shutz Jr., who was the founder of Garuda Tents, and his story of how tough it is to manufacture tents and sell them. I purchased his Pai-Mihr tent and have it to this day, but reading about his challenges at this link
http://www.byronshutzjr.org/garuda.html
Took the wind out of my sails, so it is back to the wearable sleeping bag idea because you don't have to pay someone to manufacture poles like on a tent.