Do ridgeline add strength in small solo tarp? (A-frame style)
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Timo Anttalainen
(timoa) - M

Locale: Finland, Espoo
Do ridgeline add strength in small solo tarp? (A-frame style) on 01/16/2010 09:09:16 MST Print View

Small solo tarp. Should i make it with two piece or just one? One piece tarp is easy to make, but there is limited width.

With two pieces i could make it little wider so ridgeline is center of tarp.
Or if i make tarp with three pieces and use it like A frame.

Reason to that is simple. Normally foot end is 59" (150 cm) and it's ok, but head end is too tight especially when corners are in ground. So if i add to normal flat 59"x110" (150x280 cm) tarp two triangle shaped silnylon pieces which are 10" (25 cm) wide in head end and foot end is zero.

5 yards to super ultralight tarp is good option. I make it to two persons and i going to make another and smaller solo version. I have 120" ( 3m) green silnylon and 120" (3m) grey silnylon so i can not make another tarp same way (or it would be very strange looking) .

Sorry my bad english.. I can draw picture if that help?

Nia Schmald
(nschmald) - MLife
Re: Do ridgeline add strength in small solo tarp? (A-frame style) on 01/16/2010 09:58:24 MST Print View

Certainly I'm not an expert, and the engineers can chime in. But I think the best you can do for a seam is the strength of the fabric itself, so no seam at the ridge line should be just as strong or stronger as the best seam. No?

I can think of 2 other reasons to sew a ridge line rather than the design you suggest.

1) Only 1 seam vs. 2 means one less failure point for tearing/leaking.

2) A ridg line allows you to do a catenary curve for a tighter pitch than can be easily done with a flat ridge line when pitched in an A-frame. Other pitches are harder with a catenary curve.

Neither of these points mean your design won't work and it will save fabric.

Edited by nschmald on 01/16/2010 10:17:29 MST.

Vick Hines
(vickrhines) - F

Locale: Central Texas
Re: Do ridgeline add strength in small solo tarp? (A-frame style) on 01/16/2010 15:16:54 MST Print View

Your idea for the 3 piece tarp will work just fine, especially if you put some curve in the hems all around to pull out the wrinkles. On the other hand, there is nothing wrong with putting two pieces together and using the triangles you remove to achieve the taper to make beaks at the front and rear. Either way will make a servicable tarp.

My last 2 tarps have not had a seam along the ridgeline. No problem.

Edited by vickrhines on 01/16/2010 15:28:43 MST.