Next generation snatch block

RacerAV

Active member
Thread bump. Anyone else see this video comparing blocks and rings? It seems more rigorously done than the one posted earlier in the thread (this one) and would seem to refute the idea that there’s a meaningful difference between efficiency and friction when comparing blocks and rings.

Wow that was some work!!! Thanks for the solid find!
 

Metcalf

Expedition Leader
Thread bump. Anyone else see this video comparing blocks and rings? It seems more rigorously done than the one posted earlier in the thread (this one) and would seem to refute the idea that there’s a meaningful difference between efficiency and friction when comparing blocks and rings.

I'm sure the people that just don't like the idea will be along to complain about the next 'issue' any minute now.

It is good to see some more good info coming out.

I've been soooooo happy with my snatch ring package for the last few years now.
 

Vinman

Observer
I'm sure the people that just don't like the idea will be along to complain about the next 'issue' any minute now.

It is good to see some more good info coming out.

I've been soooooo happy with my snatch ring package for the last few years now.
Yes, I’m also still happy with the snatch ring and currently looking for a second ring for complicated recoveries.
I saw that latest video last night which kicked off my search for a second ring.
 

roving1

Well-known member
I learned I am just going to use shackles for all my line doubling because I am a cheap bastard. Did I watch the video correctly? LOL. 😉
 

DaveInDenver

Expedition Leader
I learned I am just going to use shackles for all my line doubling because I am a cheap bastard. Did I watch the video correctly? LOL. 😉
Yup, a show of perfect comprehension. It was a good video, thorough and will I think reconfirm each individual's bias. The part that I admit does mine is that his crap block continues to work just fine after years of abuse. There ultimately are trade-offs each person has to consider in performance, cost, weight, longevity, reliability.
 

MartinDWhite

New member
The rope isn't being wrapped around your hawse and being asked to deal with friction indefinitely. The rope isn't the problem, it's the soft shackle IMO. Does it get warm with an extend pull? You have to be concerned with melting synthetic rope and an axle doesn't seem like an ideal application for it. It's why bearings were invented in the first place.

This reminds me of the Petzl Ultralegere. If you're a climber you'll know you always carry one of those on your harness just in case but you wouldn't use it to replace your regular haul bag pulley. Climbing, really PPE in general, is more distinct about where knots are appropriate and where hardware is used.
Look back in this thread and there are some hard numbers about heat and melting sync line. It just CAN'T happen with this type of soft shackle and aluminum block. To damage synthetic line it needs to be too hot to touch.
 

MartinDWhite

New member
I would think the soft shackle or rope used to attach the ring to your anchor would get very warm do to the friction. Would that heat weaken and cause excessive wear on that soft shackle or rope? Wouldn't the knot in the soft shackle or rope also be a weak point?
The knot is the weak point and will break in all 1/2" soft shackles at less than 40,000 lbs. specifically the rope on entry to the knot will break if the knot does not slip undone. I know this because it is the failure mode for every block I have tested.

Again....there is no where near enough heat in this type of system to cause ANY damage to the synthetic rope.
 

DaveInDenver

Expedition Leader
Look back in this thread and there are some hard numbers about heat and melting sync line. It just CAN'T happen with this type of soft shackle and aluminum block. To damage synthetic line it needs to be too hot to touch.
True, you aren't going to melt it and it's unlikely that you'll get it warm enough to reach critical temperature (Dyneema has to be kept below 150°F to avoid damage).

Screen Shot 2021-02-09 at 7.33.32 AM.png

But can't is a strong word since there's obviously some non-zero amount of friction involve. The rule of thumb threshold to sustain a burn is 70°C (~158°F) and indefinite heat tolerance is 45°C (~110°F). So we're sitting right in the region between comfortable and too hot to handle (being immediate pain) for most people.

Do you know for a fact that in use these temperatures are valid? You can't hold your hand on a spinning ring. Has Sampson a technical paper on using low friction thimble rings in this way and whether perhaps sustained lower temperatures are acceptable? I don't remember if anyone's done temperature experiments to know, particularly in the fixed shackle (that's the one that seems vulnerable) and whether the temperatures are uniform through the whole cross section. The skin of the rope might not be the same as the core. If they have and we can say with reasonable certainty then it's a moot point.

Ultimately, the great thing is you're allowed to have your opinion and I mine to what trade-offs and risks we're each willing to accept. If you feel comfortable with rigging this way that's fine. I've never argued it wasn't strictly safe (and if so that was an incorrect assessment, it seems basically safe). I just don't view mass as an absolute penalty when it can be trusted and when its wear and service life is considered.
 

Vinman

Observer
If there is an issue with synthetic line failing when used with the rings l’m sure there would be plenty of people posting there experiences by now.
 

Metcalf

Expedition Leader
Do you know for a fact that in use these temperatures are valid? You can't hold your hand on a spinning ring. Has Sampson a technical paper on using low friction thimble rings in this way and whether perhaps sustained lower temperatures are acceptable? I don't remember if anyone's done temperature experiments to know, particularly in the fixed shackle (that's the one that seems vulnerable) and whether the temperatures are uniform through the whole cross section. The skin of the rope might not be the same as the core. If they have and we can say with reasonable certainty then it's a moot point.
I can say I have done more than one back to back full pulls with 8274 trying to get a ring to even the warm. I couldn't.
Maybe if you are running a super comp PTO dual motor wiz bang comp winch you might be able to go fast enough to warm the ring up. (but probably not)
I think 99.99% of recreational winch users will have zero issues with heat related failures with a soft shackle and ring setup.
I would be WAY more worried about a crappy brake in the winch drum dragging and getting everything hot.

UHMWPE is actually a pretty dang good bearing and abrasion resistant material. It is used that way commercially in a lot of different applications.

The 'heat' issue with UHMWPE would also be two fold. Just getting the rope warm isn't enough to cause damage typically, you need to hold it under a load for a certain time AND get it hot at the same time to have any measurable creep. There are some manufacturers that do this specific process to 'set' the line and make more consistent and 'stronger'.

 

roving1

Well-known member
Yup, a show of perfect comprehension. It was a good video, thorough and will I think reconfirm each individual's bias. The part that I admit does mine is that his crap block continues to work just fine after years of abuse. There ultimately are trade-offs each person has to consider in performance, cost, weight, longevity, reliability.
Yeah in all seriousness most of my earlier doubts were unfounded I think now. I even got hands on with one that was dunked and coated with mud and grit repeatedly and used in the worse situations unlike the near lab conditions in all the vids and it still looked good and the soft shackle still looked decent considering the deliberate contamination it was put through. The only negative thing about these now is the absurd pricing in some cases.

I have one of those crap blocks that keeps on ticking lol. I think I bought it in the 90s and have lost it and found it several times in my gear piles often put away sopping wet.
 

DaveInDenver

Expedition Leader
If there is an issue with synthetic line failing when used with the rings l’m sure there would be plenty of people posting there experiences by now.
Isn't that a false positive anecdotal position? You know we also never heard about all the parachute designs that didn't work either.
 
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