Breakaway lanyards

Tom Dunlap

Tom Dunlap

Here from the beginning
Administrator
Location
Retired in Minneapolis
Lanyards keep things from getting away. But sometimes we want them to get away so a fuse is built in.

I think these are the lanyards I use:

PPE work positioning and sometimes short, second rope
Handsaw
SAKA
Neck lanyard to raise the Uni as my chest component
Chainsaw
Knife and scissors
Allen wrench for saddle shackles

Some are homemade others commercially made.

If you choose a break away lanyard where do you put the fuse?

At the tool
At the saddle
 
Tom Dunlap said:
Lanyards keep things from getting away. But sometimes we want them to get away so a fuse is built in.

I think these are the lanyards I use:

PPE work positioning and sometimes short, second rope
Handsaw
SAKA
Neck lanyard to raise the Uni as my chest component
Chainsaw
Knife and scissors
Allen wrench for saddle shackles

Some are homemade others commercially made.

If you choose a break away lanyard where do you put the fuse?

At the tool
At the saddle
Click to expand...
Weak carabiner on opposite d ring from lanyard adjuster, for convenience. I sometimes kill power, rack, then unclip (all with my right hand so I don't get mixed up. My breakaway biner is on the left d) so that I can depend on the breakaway breaking away only if the piece comes off early. If the piece comes off on time/late my breakaway can be off and I can move on my climbing line if necessary. There are obvious drawbacks to making a quick decision to unclip, but also advantages. I do what I feel is best in each circumstance.

My Echo 2511t has a breakaway wire that clips to my lanyard biner. It's one of those features that makes Echo seem cheap, but actually works really well. Their gas and oil caps with the new sock pack plastic I thingies are the other - they look so weak, have lasted so long, and are so easy to use.

I want a locking dmm xsre for my ms661. At 900 lbs., the breakaway would hurt. I wish it was a 2 or 3 kn biner. The problem is that they break easily under side loading, so a 2-3kn biner might break at more like .5 kn. Might be better if it was more circular to mitigate side loading...
 
Steve Connally said:
Rated zip ties have a very predictable breaking point! Generally at the tool
Click to expand...
Going up a tree which is clear of stubs or limbs up to a high first limb, and that limb maybe not as big as I would like, I use Richard Mumford's suggestion for newbies (in a video) of keeping two wraps of my lanyard around the tree while going up on the rope. But his, and my, fingers were holding it open to keep it moving up, so that they could get really pinched, possibly permanently damaged or even lost, if we suddenly dropped and closed that loop around the tree. And hanging there, it could be impossible to free either hand if our full weight was hanging on that lanyard pinching them. A person would be f*ked, basically, not much chance of self rescue. Using zip ties keeps the lanyard open, are quick to apply and cut away later, and break instantly if I drop. And no fingers inside the loop if it happens. I consider zip ties one of our great modern inventions, like velcro, the internet, and air conditioning.
 
Steve Connally said:
Rated zip ties have a very predictable breaking point! Generally at the tool
Click to expand...
This. Between soft and hard links (i.e. between the lanyard and the snap at the end) so if it breaks away any heavy metal bits stay captured on your harness and just the rope good flying through the air.

Also in the event it does break away, a spliced eye is way less likely to catch on something than a carabiner or snap
 
How strong is it?

I'm going to put some zip ties on my gear loops to attach rigging lines, which are, IMO, more likely to get chipped. A climb line can be bagged on a harness, or kept out of the work area, more easily.
 
It's stamped "SWL 225" whatever that means. We pulled on one with a 5:1 expecting it to take a bunch of weight but it probably didn't take 50lbs of input pull to break it and honestly for that purpose that's still more than I'd like.
 
Cereal_Killer said:
It's stamped "SWL 225" whatever that means. We pulled on one with a 5:1 expecting it to take a bunch of weight but it probably didn't take 50lbs of input pull to break it and honestly for that purpose that's still more than I'd like.
Click to expand...
“SWL” means Safe Working Load, so theoretically it’s rated to a working load of up to 225 lbs.
 
Yeah I got what it stood for, just suggesting that anything a keychain / toy says should be suspect...
I was putting under 50lbs on the pull rope, considering losses no way the keychain carabiner was even seeing 225lbs and it severely deformed.
Thats what I meant when I said "whatever that means".

I was willing to use it in that application cause I knew it'd either straighten or break completely by ~250,
 
Break-Away Chainsaw Lanyard Joint
Chainsaw Lanyard, Weaver 2 ring not breakaway, treestuff 33590 08
Join lanyard O-ring to another O-ring with upholstery thread. Attach to saddle with carabiner.
Upholstery thread will break at load.
Break away load adjustable by number of thread strands in wrap (2 strands / wrap).

Coats and Clark Upholstery thread, ARTS964 AO 900, CA00011, 100% Nylon

Thread Strength test:
1 strand 6.5 – 7.0 LB break strength
4 strand 22.0 – 23.0 LB break strength

Lanyard Load:
Echo 14" chainsaw CS3000 with Lanyard and chain guard weight: 10.0 LB

Joint Drop Test:
Wrap upholstery thread around 3/16 S Hook and ¼ inch shackle hanging from rigid garage door track. Attach Weaver lanyard with 10 LB weight and Free fall 5 feet (length of lanyard) and see if thread joint breaks
14 strand (84 LB break strength) Fail
20 strand (120 LB break strength) Fail
30 strand (180 LB break strength) 1 Pass / 1 Fail
40 strand (240 LB break strength) Pass 2 drops

Joint Design
Elected to use 30 strand joint as shock load is significantly less on body harness vs. rigid test mount.
 
Got to be careful about taking into account load equalization between the thread strands. If a loops configuration is used one more-loaded strand breaking first starts a cascade failure of the rest of the loops as well as un-anchoring the rest of the loops. Load equalization is a standard conundrum in parallel loading. Lubrication and settling in are one solution.

I once worked on 1000 lb operating kevlar/spectra/vectran "tendons" built in loop style. They really went bang on failure in the cycle jig!

IMO pull testing gives clearer results than drop testing (trying to duplicate the transient peak physically is difficult). Also hard to create a particular peak size. Also issues with rate of energy absorption in a hard stop/rigid anchor. Also have to consider the statistical variation by mfr in rating their thread.

Good on you for your efforts!
 
Bart_ said:
Got to be careful about taking into account . . . . .
Click to expand...
All good points Bart.

I do not feel comfortable with the ready made break-away lanyards being rated at 500 Lbs. I could not imagine my skeleton withstanding such a high load.

What I wanted was for my saw to go with whatever it was caught on. Up to now I have not used a chainsaw lanyard and I have had two incidents where my saw went down in a pinch. I recognize however that it would be handy if the saw was attached to myself for a number of reasons. So I want a break-away joint that I feel comfortable with, and know how it was tested.

Witnessing the 10 LB drop test, I can say that is about all I ever want on my bones. I am thinking of the hip ball and socket joint as the weak link. The rigid mount used in the drop test is a worst case impact scenario as a climbing saddle is considerably softer to absorb impact. If no impact then the break-away joint will bear the full 180 lb. load (for a 30 strand joint) for a sustained period of time before it breaks, and may not break at all if at a slightly lesser load. So now the question is do I want to be on my spurs with one leg bearing all the weight and a 180 lbs. load pulling me down from the back of my saddle?? How would I get out of that situation?

A limiting factor maybe the strength of my arms to lift the dangling weight to free the chainsaw or undo the attaching carabiner on the back of my saddle. It may also be the limiting strength of one arm to hold the weight while the other arm detaches the carabiner. I would guess that to be 60 lbs. and so a breakaway joint of 10 strands would be appropriate. However, such a joint would have very little freefall impact resistance.

I am thinking now that the best carabiner attachment point is at the chainsaw for emergency detachment. I also would like to do some drop tests with a saddle attachment to get a feel for what is practicable.
 
One consideration should be where the connection to the saddle is made. A soft gear loop or a carabiner through the main load bearing webbing. Anything that can get a significant snag I tend to clip to a soft gear loop, and that was one of the bonuses with the red loops on the og tree motion.
The bitter end of my saw lanyard has a pair of split rings and then is connected to a soft loop. Short hauled to a RE transporter through the main webbing when the say is stowed.
 
The only time I got a serious pinch.
Husky 288 on a big oak branch caught the saw, after a short period of time (split second) the saw freed itself, bent guide bar, sore hip but ok.
My take, don’t have a breakaway, saw will free itself.
 
I was once forcing my way up through conifer branches and my 200T got taken out of a small petzl caritool. It twisted/side loaded the gate open. Would you care to drop test 10 lbs onto a caritool? I suggest a jigged webbing on board simulated saddle/hip mount and lift/drop 1 ft, 2 ft working up to 5 ft. By the way, caritool is plastic probably with breakaway intention besides cheap

On a saw only lanyard I would estimate 3G's so 6 lb saw needs 18lb strength, 10 lb saw needs 30 lbs strength etc you get the idea. This brings down the risk to your hip/body/arm strength limits. Saws can be repaired easier than you.


In my absent mindedness I correlated 180 lbs with a normal buckstrap breakaway lanyard!

A trick you can incorporate is a force spike absorber even though the saddle attachment already functions as one. Drop the peak force drop the strength requirement. That applies to oops dropped the saw. Captured saw falling with log/leader its going to pop at ultimate max breakaway. hint picture a balloon inside a hollow braid you get the concept - elastomer sponge
 
The break away joint should be designed for static load as there are possible scenarios where the saw can be pinched and the lanyard drawn tight without impact. An elastomer like bungie cord can be added to the design to handle impact loads like "oops dropped the saw". So a low strength static break away of say 60 lbs. combined with bungie may be sufficient to handle a 10 lb. 5 ft. drop.

Caritools, wire ties, belt loops all good ideas for breakaways but need testing.
 
You must log in or register to reply here.

New threads New posts

Kask Stihl NORTHEASTERN Arborists Wesspur TreeStuff.com Teufelberger Westminster X-Rigging Teufelberger
Back
Top Bottom