How to attach tarp to ridgeline using Prusik knot

[Seamus1885]

Hello again,

As I mentioned before, I like to camp.  I often find myself putting up a tarp at camp and I have found that the tarp tends to sag in the middle because the attachment loops at the peak of the tarp fail to remain taut across the ridgeline.  After some research, I found that many people solve this problem by attaching the end attachment loop to the ridgeline using a Prusik knot.  They do this to A.  Prevent the loops from slipping toward the middle and, B.  Allow us to tighten the peak of the tarp by sliding the Prusik knots outwards.

So, my question is this, assuming I have a short length of 550 cord, how can I use this cord and the Prusik knot (and no caribiners) to attach the loop at the peak of the tarp to the ridgeline made of 550 cord that is suspended between two trees?

I guess what I'm trying to figure out is how to create the loop (since the Prusik itself does not knot two ends of cord together) that the Prusik needs in order to work.

I have attached a picture to help illustrate what I'm trying to accomplish.

[roo]

Hello again,

As I mentioned before, I like to camp.  I often find myself putting up a tarp at camp and I have found that the tarp tends to sag in the middle because the attachment loops at the peak of the tarp fail to remain taut across the ridgeline.  After some research, I found that many people solve this problem by attaching the end attachment loop to the ridgeline using a Prusik knot.  They do this to A.  Prevent the loops from slipping toward the middle and, B.  Allow us to tighten the peak of the tarp by sliding the Prusik knots outwards.

So, my question is this, assuming I have a short length of 550 cord, how can I use this cord and the Prusik knot (and no caribiners) to attach the loop at the peak of the tarp to the ridgeline made of 550 cord that is suspended between two trees?

I guess what I'm trying to figure out is how to create the loop (since the Prusik itself does not knot two ends of cord together) that the Prusik needs in order to work.

You can just bend the end of the cord together with the bend of your choice.  Maybe:

http://notableknotindex.webs.com/Zeppelin.html

You don't have to use a Prusik knot.   Other ascender-type knots can work:

http://notableknotindex.webs.com/sailorhitches.html
http://notableknotindex.webs.com/blakeshitch.html

And with only one line required, things are less bulky and you can use a simple hitch or loop to tie off to the tarp.  For example:

http://notableknotindex.webs.com/gnathitch.html
http://notableknotindex.webs.com/bowline.html

I think a tensioner like a Versatackle will probably hold up better than to motion and wind than ascender-type knots:

http://notableknotindex.webs.com/Versatackle.html

[Seamus1885]

Thanks a lot Roo.  That Zeppelin bend looks the be the most simple and effective.  I think I might try that one first.  If that leaves me wanting something else, I'll try your other suggestions.  Thanks again.

[Dan_Lehman]

Why would one not simply lay the tarp over the ridgeline rope?

As for the ridgeline ends of the tarp, possibly one could be secured
with the ridgeline rope (I'm unsure of relative sized of rope & clew),
and the other would need only some short line to secure it.  Rather
than the Prusik hitch, a simple rolling h. maybe guarded by a
half-hitch will be easier to put in.


--dl*
====

[Hrungnir]

I do a lot of hiking myself, and I would recommend to make the system as simple as possible. The reason why is you will be cold, have frozen hands, hungry, tired (sleepy, exhausted, no energy) when you are going to make camp. It also might be dark, cold and windy.

You also want a rope efficient system. You want to carry as little weight as possible when you might walk 10-30km a day for a week or a weekend. Up and downhill, through difficult terrain and weather. Some people break the handle off their toothbrush, just to save a couple of grams more. Or dry their toothpaste and calculate how much they're gonna use during the trip. You can get a lot of toothpaste for 1-2 meters of rope.

When tying up your tarp I would use only two knots. Two half hitches to attach the ridgeline to the tree. Instead of using a prusik (too difficult and slow to tie), I would use either a tautline hitch or a adjustable grip hitch to make the rope taut. I would use the same system to tie the guy lines. Two half hitches to one end and tautline hitch on the other to make the rope taut.

The (roundturn and) two half hitches is very fast, easy and rope efficient to tie. You can also tie it on the bight if you have too much rope. Tie it with a slip if it's cold, wet and windy, then your knot won't be too difficult to untie in the morning. If wanted, you can add one or two roundturns to make the hitch grip the tree better.

The tautline hitch and adjustable grip hitch don't add as much "grip strength" as the prusik, and you can't get the rope as taut as with the versatackle. But they are much simpler knots, you can tie them much faster and much easier to get right the first time. They make the rope taut enough (you don't need the tremendous strength of the versatackle for this purpose) and by adding more turns you can get more "grip strength".

Roundturn and two half hitches: http://notableknotindex.webs.com/roundturntwohalfhitches.html
Tautline hitch: http://www.netknots.com/rope_knots/tautline-hitch/ Or adjustable grip hitch: http://www.hawaiilibrary.net/article/whebn0001464710/adjustable%20grip%20hitch

[Dan_Lehman]

I do a lot of hiking myself, and I would recommend to make the system as simple as possible.
The reason why is you will be cold, have frozen hands, hungry, tired (sleepy, exhausted, no energy)
when you are going to make camp.  It also might be dark, cold and windy.

Knots in the Wild, not in the Armchair !!   

(As one who has had his hassles with too-clever-by-half
fiddlings in times of need, I heartily concur in Hungrir's
sage advice!)


--dl*
====

[Seamus1885]

Why would one not simply lay the tarp over the ridgeline rope?

As for the ridgeline ends of the tarp, possibly one could be secured
with the ridgeline rope (I'm unsure of relative sized of rope & clew),
and the other would need only some short line to secure it.  Rather
than the Prusik hitch, a simple rolling h. maybe guarded by a
half-hitch will be easier to put in.


--dl*
====

Good question Dan.  Using the attachment loops on a tarp extends the life of the tarp considerably.  The constant rubbing of the tarp against the cord cuts down on the life tremendously.  It also helps keep the ridge of the tarp taut along the ridgeline because the attachment loops give the user something to tie to the ridgeline to keep the tarp from sagging toward the middle.

Thanks a lot for your alternative knot suggestion.  I'll look into it.

[Seamus1885]

I do a lot of hiking myself, and I would recommend to make the system as simple as possible. The reason why is you will be cold, have frozen hands, hungry, tired (sleepy, exhausted, no energy) when you are going to make camp. It also might be dark, cold and windy.

You also want a rope efficient system. You want to carry as little weight as possible when you might walk 10-30km a day for a week or a weekend. Up and downhill, through difficult terrain and weather. Some people break the handle off their toothbrush, just to save a couple of grams more. Or dry their toothpaste and calculate how much they're gonna use during the trip. You can get a lot of toothpaste for 1-2 meters of rope.

When tying up your tarp I would use only two knots. Two half hitches to attach the ridgeline to the tree. Instead of using a prusik (too difficult and slow to tie), I would use either a tautline hitch or a adjustable grip hitch to make the rope taut. I would use the same system to tie the guy lines. Two half hitches to one end and tautline hitch on the other to make the rope taut.

The (roundturn and) two half hitches is very fast, easy and rope efficient to tie. You can also tie it on the bight if you have too much rope. Tie it with a slip if it's cold, wet and windy, then your knot won't be too difficult to untie in the morning. If wanted, you can add one or two roundturns to make the hitch grip the tree better.

The tautline hitch and adjustable grip hitch don't add as much "grip strength" as the prusik, and you can't get the rope as taut as with the versatackle. But they are much simpler knots, you can tie them much faster and much easier to get right the first time. They make the rope taut enough (you don't need the tremendous strength of the versatackle for this purpose) and by adding more turns you can get more "grip strength".

Roundturn and two half hitches: http://notableknotindex.webs.com/roundturntwohalfhitches.html
Tautline hitch: http://www.netknots.com/rope_knots/tautline-hitch/ Or adjustable grip hitch: http://www.hawaiilibrary.net/article/whebn0001464710/adjustable%20grip%20hitch

I'll only need to tie the Prusik knot once as it stays tied for transportation.

[Fairlead]

I am going to be daubed a "philistine" for this but take a look at it Seamus 1885.
http://theultimatehang.com/2012/04/rubber-band-tarp-line-tensioners/
I am also tempted to get you to investigate the use of the so-called "Whoopie Sling" and "Soft Shackles"
- both of which can be made using 550 with the cores removed -
to get you interested in "Hollow Braid Splicing" (there are plenty of You-Tube videos on the subject).

Gordon

[Sweeney]

I am going to be daubed a "philistine" for this but take a look at it Seamus 1885.

Not by me Gordon! This is a neat idea for maintaining tension - which could be useful in a few applications. I have been wondering what to do with a roll of bungee cord..........

Barry