tents with catenary ridgeline - WhiteBlaze

markellag · 01-07-2005, 07:37

I think that claiming a tent is a superior design because it has catenary ridgeline is a silly. I think a straight line ridgeline is probably 99% as good as a catenary ridgeline.

Lone Wolf · 01-07-2005, 07:41

Can't find CATENARY in the dictionary. What the hell does it mean?

MOWGLI · 01-07-2005, 07:46

Quote:

Originally Posted by L. Wolf

Can't find CATENARY in the dictionary. What the hell does it mean?

From a Google Search:

The catenary is the shape of a perfectly flexible chain suspended by its ends and acted on by gravity. Its equation was obtained by Leibniz, Huygens and Johann Bernoulli in 1691. They were responding to a challenge put out by Jacob Bernoulli to find the equation of the 'chain-curve'.

Huygens was the first to use the term catenary in a letter to Leibniz in 1690 and David Gregory wrote a treatise on the catenary in 1690. Jungius (1669) disproved Galileo's claim that the curve of a chain hanging under gravity would be a parabola.

The catenary is the locus of the focus of a parabola rolling along a straight line.

The catenary is the evolute of the tractrix. It is the locus of the mid-point of the vertical line segment between the curves ex and e-x.

Euler showed in 1744 that a catenary revolved about its asymptote generates the only minimal surface of revolution.

Ya know, I had no idea that the "The catenary is the locus of the focus of a parabola rolling along a straight line". Did you?

hungryhowie · 01-07-2005, 08:45

Quote:

Originally Posted by MOWGLI16

Ya know, I had no idea that the "The catenary is the locus of the focus of a parabola rolling along a straight line". Did you?

Actually, it's not. I think that's been disproven now.

Catenary curves are used far less frequently than one would think. It is much simpler and less expensive to use arcs. Even suspension bridges, whose cables are initially catenaries, form a parabolic shape after the weight of the bridge is added.

Derived from the Latin word meaning “chain”, a catenary curve is the sag of a cord hung from both endpoints. While, in theory, any free-hanging homogenous cable creates a natural catenary, dense, non-stretchable, and fully flexible cords are best equipped for doing so in practical circumstances. Chains, which meet all of these criteria, are used frequently as an example of a catenary.

It is also interesting to note that unlike other curves, there is only one catenary. While different lengths and drops may at first appear to look different, it is no different than zooming in on a circle, which looks increasingly straighter as you zoom in.

To answer the original question or concern, however, I would argue that catenary designs are worthy of being marketed as superior to those without. While two shelters, identical save catenary design, will keep you just as dry, the one with a catenary cut will sag less, lessening the chances for the fabric to come in contact with your sleeping bag and therefore lessening the chance that your bag will get wet from condensation. Further, the shelter with a catenary cut will flap less in the wind, translating into a quieter shelter, and perhaps better sleep for the occupant(s).

As a manufacturer, would you not market a shelter that boasts the same protection, but with added benefits of less sag and better wind performance as superior? I know I would.

It's tantimount to implying that car manufacturers shouldn't market cars with more advanced safety features as superior to their counterparts without them. Would you rather have a car with ABS or without? Stability control or without? Crumple zones or without?

-howie

chris · 01-07-2005, 08:54

If you want to impress the ladyfolk (trust me, this really works), replace catenary with: "negative curvature". That's right, my tarp tent is an example of a locally embedded negatively curved manifold. Women swoon when they hear what a wonderful thing I have in my sack. How could that possibly be silly?

MOWGLI · 01-07-2005, 08:59

Quote:

Originally Posted by hungryhowie

Stability control or without? Crumple zones or without?

-howie

Now if we could only design hikers with greater stability control and crumple zones, it'll really help with hiking those slick trails in northern New England.

"Hey, that looked like a bad fall!"

"Not to worry, I fell on my crumple zone. My stability control system must have suffered a suboptimization".

Youngblood · 01-07-2005, 10:02

A catenary curve is often used to achieve maximum structural stength and is used with some tents to achieve maximum wind loading as a structure. It is common in arches used to support heavy loads (bridges, overpasses and such), cable supports on suspension bridges and such. It is also the curve that you see on power lines hanging between two poles because of the effect of gravity. It is real and it is in structural designs that us city folks use every day... and for good reason.

I use it on my homemade tarps that I always pitch in an A-frame with my hammocks and the catenary curves work very well at helping me get a taut pitch.

Youngblood

fullofadventure · 01-07-2005, 20:03

http://www.tarptent.com/catenary.html

brian · 01-07-2005, 20:21

WHile the tarptent site may be true, a catenary cut ridgeline is sometimes not needed. If the tarp is pulled taught while it is setup, the resulting bend in the ridgeline gives the same qualities of a catenary cut tarp, while still allowing tarp setups which may be more difficult with a cat ridgeline.

For a hammock, it also depends on whether you tie your tarp to the hammock itself, or to the tree. Tying to the hammock may not provide enough elevation for a hammock tarp to fully take advantage of the possible curve.

Brian

SiuWonfung · 01-07-2005, 20:22

If you thought a catenary ridgeline tent was something, you should check out craviculary cantancerous cultivated clapulcalated interrogated lithium-battery-powered tents. to the best of my knowledge, they're the best in terms of weight-to-colour ratio.
but, if you're looking for something with a better weight-to-zipper area ratio, then i think that a catenary ridgeline tent is your best bet.

Percival · 01-07-2005, 20:30

If Siuwonfong is really in Portugal, by my reckoning it's about 2:00 A.M. there and he's really tanked up on Spanish wine.

TDale · 01-07-2005, 20:35

Quote:

Originally Posted by MOWGLI16

The catenary is the locus of the focus of a parabola rolling along a straight line.

They actually have math for that? Huh!

markellag · 01-07-2005, 21:25

SiuWonfung is a head hunter.
I thought head hunters where not allowed access to this web site.

Quote:

Originally Posted by SiuWonfung

If you thought a catenary ridgeline tent was something, you should check out craviculary cantancerous cultivated clapulcalated interrogated lithium-battery-powered tents. to the best of my knowledge, they're the best in terms of weight-to-colour ratio.
but, if you're looking for something with a better weight-to-zipper area ratio, then i think that a catenary ridgeline tent is your best bet.

01-07-2005, 07:37	#1
markellag hansome,intelligent,rich, zealot,cancer survivor Join Date: 07-29-2004 Location: Huntsville, Alabama Age: 63 Posts: 43	tents with catenary ridgeline I think that claiming a tent is a superior design because it has catenary ridgeline is a silly. I think a straight line ridgeline is probably 99% as good as a catenary ridgeline.

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01-07-2005, 07:41	#2
Lone Wolf Registered User Join Date: 11-20-2002 Location: Damascus, Virginia Age: 51 Posts: 24,097	Can't find CATENARY in the dictionary. What the hell does it mean?

01-07-2005, 08:54	#5
chris Registered User Join Date: 09-05-2002 Location: Lakewood, WA View my gallery 118 Age: 36 Posts: 1,971 Images: 118	If you want to impress the ladyfolk (trust me, this really works), replace catenary with: "negative curvature". That's right, my tarp tent is an example of a locally embedded negatively curved manifold. Women swoon when they hear what a wonderful thing I have in my sack. How could that possibly be silly?

01-07-2005, 10:02	#7
Youngblood GAME 2000 Join Date: 09-12-2002 Location: Doraville, Georgia View my gallery 155 Age: 61 Posts: 1,563 Images: 155	A catenary curve is often used to achieve maximum structural stength and is used with some tents to achieve maximum wind loading as a structure. It is common in arches used to support heavy loads (bridges, overpasses and such), cable supports on suspension bridges and such. It is also the curve that you see on power lines hanging between two poles because of the effect of gravity. It is real and it is in structural designs that us city folks use every day... and for good reason. I use it on my homemade tarps that I always pitch in an A-frame with my hammocks and the catenary curves work very well at helping me get a taut pitch. Youngblood

01-07-2005, 20:03	#8
fullofadventure Registered User Join Date: 06-07-2004 Location: Langley, B.C., Canada Age: 34 Posts: 44	http://www.tarptent.com/catenary.html

01-07-2005, 20:21	#9
brian GA to ME someday... Join Date: 02-17-2003 Location: West Point NY View my gallery 8 Age: 22 Posts: 278 Images: 8	WHile the tarptent site may be true, a catenary cut ridgeline is sometimes not needed. If the tarp is pulled taught while it is setup, the resulting bend in the ridgeline gives the same qualities of a catenary cut tarp, while still allowing tarp setups which may be more difficult with a cat ridgeline. For a hammock, it also depends on whether you tie your tarp to the hammock itself, or to the tree. Tying to the hammock may not provide enough elevation for a hammock tarp to fully take advantage of the possible curve. Brian

01-07-2005, 20:22	#10
SiuWonfung Marcus Join Date: 01-01-2005 Location: Oberosterreich, Austria View my gallery 1 Age: 61 Posts: 49 Images: 1	If you thought a catenary ridgeline tent was something, you should check out craviculary cantancerous cultivated clapulcalated interrogated lithium-battery-powered tents. to the best of my knowledge, they're the best in terms of weight-to-colour ratio. but, if you're looking for something with a better weight-to-zipper area ratio, then i think that a catenary ridgeline tent is your best bet.

01-07-2005, 20:30	#11
Percival Registered User Join Date: 10-05-2003 Location: Richmond, VA Posts: 137	If Siuwonfong is really in Portugal, by my reckoning it's about 2:00 A.M. there and he's really tanked up on Spanish wine.