Oplux / rescue tech | Custom length 7mm vt prusik from Bluewater ropes.

[raisins]

Hi all,
Just stumbled unto this thread as I was searching for dimensional standards for Prusiks. I have a 11.4mm Samson Predator Lineman and Tether based on the info above, 11.4mm - 40% = 6.84mm thickness is probably a fair middle of the road thickness I would want for a prusik? or do I have this backwards? Also in reading this thread, I'm wondering if 24" isn't kinda long. I've seen sewn 19" prusik (continuous loop) and something else called a 13.5" Auto Block Cord (continuous loop).

I would consider that on the thin side. Wesspur has a sewn eye prusik cord that is made to pair with Predator. It's a good bit thicker. Aero Hunter used to sell it as a kit. I just measured mine and it was 9.21 mm in diameter and grabs well. I would try 7, 8, and 9 mm. I bet you'll end up with 8 or 9 mm. With the thicker arborist ropes, it seems that 10 mm is most common.

Predator 11.4mm Climbing Rope

Camoflauged double-braid climbing line at 11.4mm from Samson. This is an excellent climbing line that will work with your favorite hitch cords and climbing hardware, but allows you to keep a low profile in the tree. Perfect for rec climbs, saddle hunting, canopy research, and any other climbing...

www.wesspur.com

 

[IslandStorm62]

Thanks. Well, I jumped and got a 19" sewn Sterling 7mm prusik w/ 3800 MBS...guess I'll be about 1600 lbs below some arborist regulation. I realize that they had some genius figure out what is required regarding safety. I' just have to figure 170 lbs dropping 2 - 3 feet would hopefully not generate 3800 lbs of pressure. I suppose I feel okay about that. I am now more concerned if the different diameters will cause the prusik to not hold.

 

[raisins]

Thanks. Well, I jumped and got a 19" sewn Sterling 7mm prusik w/ 3800 MBS...guess I'll be about 1600 lbs below some arborist regulation. I realize that they had some genius figure out what is required regarding safety. I' just have to figure 170 lbs dropping 2 - 3 feet would hopefully not generate 3800 lbs of pressure. I suppose I feel okay about that. I am now more concerned if the different diameters will cause the prusik to not hold.

I believe if you have two points of attachment, that each end only see half the weight it would if it were one loop, given that it is a friction hitch on the top side which disrupts the loop weakness on that side. But an arborist/climber will hopefully chime in. I use 6 mm TRC with two scaffold knots to replace the eyes, and I don't feel unsafe (3484 lbs strength).

 

[sojourner]

Hi all,
Just stumbled unto this thread as I was searching for dimensional standards for Prusiks. I have a 11.4mm Samson Predator Lineman and Tether based on the info above, 11.4mm - 40% = 6.84mm thickness is probably a fair middle of the road thickness I would want for a prusik? or do I have this backwards? Also in reading this thread, I'm wondering if 24" isn't kinda long. I've seen sewn 19" prusik (continuous loop) and something else called a 13.5" Auto Block Cord (continuous loop).

I have Sampson predator. The best friction hitch cordage I found for that is armor-prus 8mm sewn eye to eye. Using a distel hitch and a DanO hitch tender, 28” worked out as the perfect length for me. Armor-prus is strong, grips quick, releases easily and is no fiddly needing constant attention to how it is “dressed” around the Predator.

Back to oplux or rescue tech, that is 8mm rope. I was looking for the best, aka highest breaking strength friction hitch cordage to work with that. That led to Bluewater vt-prusik cordage and getting a custom length.




.

 

[IslandStorm62]

I have Sampson predator. The best friction hitch cordage I found for that is armor-prus 8mm sewn eye to eye. Using a distel hitch and a DanO hitch tender, 28” worked out as the perfect length for me. Armor-prus is strong, grips quick, releases easily and is no fiddly needing constant attention to how it is “dressed” around the Predator.

Back to oplux or rescue tech, that is 8mm rope. I was looking for the best, aka highest breaking strength friction hitch cordage to work with that. That led to Bluewater vt-prusik cordage and getting a custom length.

Thanks. Great picture. That 28" friction hitch length looks like it was just barely enough to get your distel wrapped on. I might have to reconsider the length of the friction hitch rope; Unless using the sewn eye to eye "distel" needs more length than a continuous loop "prusik". I just don't want an extra 3 or 4 inches of loop dangling above the carabiner.

But as far a the diameter of the friction rope goes, I found this tidbit out at the RNR Site...short story - the (11.4mm or 7/16 inch) predator can use a 7mm prusik (friction cord).

 

[phatkaw]

I have 4 different hitches coming in the mail...
I'm short ( 5' 7" ) so I NEED to shorten pretty much everything that I have now.
I spent most of the day today tying different hitches and adding wraps at the top or bottom. I did this mostly on my LB and testing on a tree in my yard with my spurs. The 'true' Swabisch works the best for me but 28" is just too damn long...
If I add any wraps the hitch won't break for me after having weight on it.


^^^ 12.5mm rope and an a 28" 8mm eye to eye.

 

[IslandStorm62]

Thanks...your 28" looks longer than the photo before yours. Yeah I'm not wanting that extra 3 -4 inch loop. my rope is 11.4mm and I am thinking I'll stick with the 7mm though I suppose 8mm won't make much more of a difference...just get me closer to the arborist regulations, I guess. BTW very good pix, I can read the friction hitch label. Thanks again.

 

[Fl Canopy Stalker]

Hi all,
Just stumbled unto this thread as I was searching for dimensional standards for Prusiks. I have a 11.4mm Samson Predator Lineman and Tether based on the info above, 11.4mm - 40% = 6.84mm thickness is probably a fair middle of the road thickness I would want for a prusik? or do I have this backwards? Also in reading this thread, I'm wondering if 24" isn't kinda long. I've seen sewn 19" prusik (continuous loop) and something else called a 13.5" Auto Block Cord (continuous loop).

For your Sampson predator a prusik around 8mm to 9mm would be ideal

 

[Fl Canopy Stalker]

Thanks. Great picture. That 28" friction hitch length looks like it was just barely enough to get your distel wrapped on. I might have to reconsider the length of the friction hitch rope; Unless using the sewn eye to eye "distel" needs more length than a continuous loop "prusik". I just don't want an extra 3 or 4 inches of loop dangling above the carabiner.

But as far a the diameter of the friction rope goes, I found this tidbit out at the RNR Site...short story - the (11.4mm or 7/16 inch) predator can use a 7mm prusik (friction cord).

Yes but the 7mm will bite down insanely hard and be hard to move when you unweight it. A good rule of thumb is 60-80% or your rope size with 70-75% being ideal . 8mm is just under 71% of 11.4 rope so 8 mm would be perfect. There are companies such as Rock N Rescue also GM climbing makes a nice 8mm prusik rated to over 4250 lbs straight pull and over 5000 in loop. They are fairly cheap if you do not mind buying Chinese. (Keep in mind most stuff from metolius and black diamond are now made in China. Again it depends on your personal preferences

 

[phatkaw]

There are companies such as Rock N Rescue also GM climbing makes a nice 8mm prusik rated to over 4250 lbs straight pull and over 5000 in loop. They are fairly cheap if you do not mind buying Chinese. (Keep in mind most stuff from metolius and black diamond are now made in China. Again it depends on your personal preferences

I shopped my butt off last night... I found each hitch I wanted at different places. That sucked because of the shipping prices I would've had to pay. The one I found was just what I wanted for my bridge but they wanted like 22 bucks to ship it.
I had to compromise a little But I'm excited to try 'em out when they all get here.

 

[raisins]

I have 4 different hitches coming in the mail...
I'm short ( 5' 7" ) so I NEED to shorten pretty much everything that I have now.
I spent most of the day today tying different hitches and adding wraps at the top or bottom. I did this mostly on my LB and testing on a tree in my yard with my spurs. The 'true' Swabisch works the best for me but 28" is just too damn long...
If I add any wraps the hitch won't break for me after having weight on it.

View attachment 46317
^^^ 12.5mm rope and an a 28" 8mm eye to eye.

what cord is that hitch? sorry if you've already mentioned it upstream.

 

[Brocky]

Sterling Flex

 

[phatkaw]

What he said ^^^.

It's nice but pretty dang long...

 

[Brocky]

One option for that long sewn cord, if it’s long enough, the eye works nice for a tender.
The other is just a piece of cord, the stopper knot in back tends the hitch.

 

[tmattson]

Great idea. Is that knott in the top pic just a double back through?

 

[sojourner]

Thanks. Great picture. That 28" friction hitch length looks like it was just barely enough to get your distel wrapped on. I might have to reconsider the length of the friction hitch rope; Unless using the sewn eye to eye "distel" needs more length than a continuous loop "prusik". I just don't want an extra 3 or 4 inches of loop dangling above the carabiner.

But as far a the diameter of the friction rope goes, I found this tidbit out at the RNR Site...short story - the (11.4mm or 7/16 inch) predator can use a 7mm prusik (friction cord).

Continuous loop will have rope overlap where it is sewn and added to length from biner to where the hitch wraps around the rope. For eye to eye the area sewn and covered in plastic, same thing.

I ordered from Wesspur and specified the length. I took into account the length of the plastic to get the shortest tail ends on the distel. And fortunately, the DanO tender’s length matched that length perfectly.

If you go no sewn ends (and a poachers or scaffold knot to connect to the biner), it will not be as long as the plastic on the sewn ends. It’ll be “fatter”, but not longer. Also, sewn ends retain more strength that using a scaffold or poachers knot.

My last input for you, prusik is just one type of friction hitch. It catches in both directions. And after weighted, it can be difficult to move.

Distel, klemheist, schwabisch hitches catch in one direction (we only need catching in one direction for our applications), are easier to move after being weighted especially with the use of a hitch tender.

I speculate that if you initially start with a prusik friction hitch, you will experience the pain of “tending” your LB and tether. You will take either one route (asymmetric friction hitch, e.g., distel, and tender) OR another route (ropeman or kong duck).

Happy hunting and stay safe.

 

[sojourner]

Thanks. Great picture. That 28" friction hitch length looks like it was just barely enough to get your distel wrapped on. I might have to reconsider the length of the friction hitch rope; Unless using the sewn eye to eye "distel" needs more length than a continuous loop "prusik". I just don't want an extra 3 or 4 inches of loop dangling above the carabiner.

But as far a the diameter of the friction rope goes, I found this tidbit out at the RNR Site...short story - the (11.4mm or 7/16 inch) predator can use a 7mm prusik (friction cord).

Continuous loop will have rope overlap where it is sewn and added to length from biner to where the hitch wraps around the rope. For eye to eye the area sewn and covered in plastic, same thing.

I ordered from Wesspur and specified the length. I took into account the length of the plastic to get the shortest tail ends on the distel. And fortunately, the DanO tender’s length matched that length perfectly.

If you go no sewn ends (and a poachers or scaffold knot to connect to the biner), it will not be as long as the plastic on the sewn ends. It’ll be “fatter”, but not longer. Also, sewn ends retain more strength that using a scaffold or poachers knot.

My last input for you, prusik is just one type of friction hitch. It catches in both directions. And after weighted, it can be difficult to move.

Distel, klemheist, schwabisch hitches catch in one direction (we only need catching in one direction for our applications), are easier to move after being weighted especially with the use of a hitch tender.

I speculate that if you initially start with a prusik friction hitch, you will experience the pain of “tending” your LB and tether. You will take either one route (asymmetric friction hitch, e.g., distel, and tender) OR another route (ropeman or kong duck).

Happy hunting and stay safe.

 

[Brocky]

Great idea. Is that knott in the top pic just a double back through?

I was able to get a scaffold knot with a little difficulty, a single wrap, overhand knot would also work. With the rope through the eye it can’t come untied.

 

[wingnut]

One option for that long sewn cord, if it’s long enough, the eye works nice for a tender.
The other is just a piece of cord, the stopper knot in back tends the hitch.
View attachment 46334

That looks like a great way to get double use from a longer sewn cord. What length cord did you use?

 

[Brocky]

The sewn cord is the standard one of 32”, the Flex is 54”, and they’re on 10.5mm rope.