SCARP 2 winter mods photos
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Ryan Jordan
(ryan) - BPL Staff - MLife

Locale: Greater Yellowstone
Re: Re: Scarp Mods on 12/03/2013 22:31:43 MST Print View

I certainly don't have the tent design experience that you have, Henry. Thank you for your humble reminder ;)

I really like the Scarp. I just really want it to be a 4-season tent that can handle snow loading without the unsupported fabric between the sticks sagging.

Also -- I'm sorry for the patent-stick jab. It was meant in good fun and not a sincere criticism. It's clear the sticks add a lot to your designs.

--

Also re: end hoops, noted about the tight radius...

All this is motivated by my current immersion in a winter tent testing project and general frustration by people calling tents 4-season tents but with unsupportive fabric panels that sag a lot under even low (a few inches) snow loads.

Tent designer I'm not, so I'll stand down on my grand ideas for redesigning TarpTents!

Winter tent user I am, so I'll try to keep to keep the ego billowed small enough so that it remains contained in the vestibule!

Samuel C. Farrington
(scfhome) - M

Locale: Chocorua NH, USA
Scarp and Winter on 12/04/2013 21:13:39 MST Print View

As a publicist, or whatever Ryan calls his work, he has to try to please all of the people all of the time. A hopeless task, of course. I used to have to do that also, but not anymore. Ain't it great!

Franco Darioli
(Franco) - M

Locale: Melbourne
SCARP 2 winter mods photos on 12/04/2013 22:39:10 MST Print View

Yes and as tent designer Henry needs to obey the laws of physics.

The "sticks" that form the Pitch Lock corner (plus the two mid ones) of the Scarp are 10x 18" Carbon Fiber tubes weighing a total of 3.5 oz.
Now see if you can make two arch poles that can hold up a foot or two of snow for less than that ,even using pre-bent tubes.
Do keep in mind also the Scarp footprint.

Samuel C. Farrington
(scfhome) - M

Locale: Chocorua NH, USA
physics on 12/05/2013 16:56:43 MST Print View

Franco,
If you mean applying force directly to the end of the carbon strut, and thus along its length as in your photo, OK. Indeed, an acrobat could probably stand balanced on the tops of the struts. But the snow will also land on the fabric spanning between the top tips of the struts.

I understood Ryan's point to be that the small hoop would spread the weight of the snow over the entire hoop, thus keeping the fabric from sinking all along the length of the hoop. Sure, you could not stand on the hoop without breaking it. But the weight of the snow will be spread over a greater length than the width of your foot.

I have break-tested a bunch of carbon struts, and the ones I chose, in conjunction with a prebent Nanolite in the center, would easily hold up under a foot of snow.
The problem would be with the fabric span from the end hoops up to the larger center hoop. The tension on the tent would have to be enormous to hold up the snow where the fabric is unsupported. That's why I don't like hoop tents in the first place.
But they do save pole weight, and perform well in heavy winds and rain.

In addition to the loss of some space, another issue with a hooped end, as opposed to a box-shaped end like the Scarp's, is being able to open the door without loosening the canopy and making the tent vulnerable to nasty weather. The top points of the pitch-locks act as the point of a partial cone, keeping the canopy taut no matter how far the door is opened. It is very difficult to come up with a design to do this between two hoops, rather than a boxed end. That may be another advantage of the Scarp.
Googling the Golite Eden brings up some photos down the page of Ryan's suggested tent:
https://www.google.com/#q=golite+eden+tent

It is difficult to tell from the Eden photos how taut the canopy remains as the door is opened, but I think it can be a problem. Looseness in the canopy can create a lot more havoc than imagined when rain is pouring onto it and the wind is flapping it about. I never saw one of the Eden tents in person, so don't know if Golite addressed the problem. That's the issue I was thinking about avoiding when referring to daydreaming about different ways to use struts to support the ends of an Akto, a tent with an end more boxed like the Scarp's.

Kevin Buggie
(kbuggie) - M

Locale: NW New Mexico
Cloudburst 3 on 12/05/2013 17:59:05 MST Print View

Isn't the TT Cloudburst 3 closer to the tent RJ is imagining? Its got additional guy lines to solve the door-open tension problem mentioned above, and already a tunnel tent.

If the CB3 was smaller in all dimensions, had a true sleeve for the 3rd pole, and a true double-wall interior I bet it would be a popular UL winter tent. Probably at half the ballpark cost of the Caffin tunnels when they're finally available.

@Franco (and HS) why hasn't TT jumped into the 4-season market beyond the Moment DW and Scarp 2 (ie. A true winter tunnel tent)? Seems like you could sell a ton at a higher price point than most of your gear (say $400 ish) and still be a fair bit lighter than the $500-600 tents in that category.

Edited by kbuggie on 12/05/2013 18:12:49 MST.

Franco Darioli
(Franco) - M

Locale: Melbourne
SCARP 2 winter mods photos on 12/05/2013 19:26:40 MST Print View

Kevin, let's keep this between the two of us...

Henry likes to design the sort of shelters he likes to use.

The only exception that I can think of was the SS1/2, that really was done as design challenge and I think he nailed it.

Eric Blumensaadt
(Danepacker) - MLife

Locale: Mojave Desert
Wait! Wait! on 12/05/2013 20:00:41 MST Print View

Please, just one more word from a geezer winter camper on winter tent design:
(Bearing in mind 4 season tents ARE a compromise to fit all seasons, let me just talk WINTER tents here.)

GOALS OF WINTER TENTS:

1.Safety in storms -> i.e strength and reliability
2.Lightest feasable weight-> lighest SAFE materials in poles and fabrics given expected max winds and snow load.

Given these two main goals designers have found that MINIMIZING UNSUPPORTED FABRIC AREAS creates stronger tents for both wind and snow load. Thus the geodesic dome's popularity in high altitude mountainering. Great shape and great strength.

BUT, geodesic domes are weighty due to all the poles and their attatchment points.

THERFORE tunnel tents, the next best winter tent shape (IMHO), reduce weight but increaase unsupported area, losing some strength.

Hilleberg has designed UNEQUAL HEIGHT tunnel tent hoops to help gain strength and aerodynamics at the cost of some interior head room. Probably the best we can hope for in design compromise. They also use one or two CROSSING POLES to give strength in some tents. Agin, a compromise, adding weight for additional safety.

As Eric Chan quoted, "There's no such thing as a free lunch."

The reason I like the Scarp design is that it IS a compromise but one that has flexibility of design with the option of crossing poles for bad weather. It works fine either way, depending on weather.

Tent design advances have utilized new fabrics (Cuben and silnylon, for ex.) and new pole technology (DAC and CF poles and aluminum and polymer pole connectors and attatchment points). Perhaps better lightweight waterproofing is on the way. Perhaps better closures than the current nylon zippers are coming too.
With these advances in lower weight materials, clever pole configuration and out-of-the-box shapes we are far ahead of the EUREKA! Timberline wedge tent of the '70s.

Ain't tent design FUN?!