Safer use of D and anchor shackles... (1 Viewer)

[e9999]

I see this pretty often. Folks using anchor shackles that end up cockeyed when under tension, with the hooks, cable, block etc stuck in one corner between the main body and the bolt; and the whole thing at an angle w.r.t. the main tension direction.

IIRC, the strength of the shackle is greatly decreased when it's not aligned properly...

Solution: I carry a bunch of large washers of various sizes on my shackles. (All of $5 at the local hardware store). When I use a shackle I just insert enough washers on the main bolt that whatever it's attached to is forced to stay in the middle of the bolt.

 

[Cruiserdrew]

You're kidding right?


If not, I'll sell you some Anchor Shackle alignment washers for $5 each.
$10 if you want the heat treated ones, and $15 for the chrome ones for Jeeps.

 

[Ian Rogers]

no S***, E9999 what are you talking about. You must be making stuff up

 

[e9999]

it's not that complicated guys:
- you go to the hardware store
- you pick up a bunch of washers in various sizes (3/4" to 1 1/8" ID in my case), about 6 or so per size
- you go to the cash register
- you pay (about $5 as mentioned above)
- you go home
- you put the washers on the shackles as needed
- obviously, you have to put them on both sides of the loop, tie down point etc
- they keep the shackle straight



if it's the drop in strength that has you baffled, think shear vs tensile stress...

 

[Mark W]

Not really a bad idea, but it seems like you're overthinking this to be honest. If you are woking so close to the limit of your rigging gear that misalignment will damage it... Just upgrade to heavier gear. Especially shackles. These are usually far and away the strongest part of the rigging.

In the last 20-25 years I have never damaged a shackle and I have ever seen anyone with me damage one either.

For me anyway, it would not be worth the time/effort to insert the washers on the shackle. Particularly in cold mud or snow or under running water.


Mark...

 

[Cruiserdrew]

Just upgrade to heavier gear. Especially shackles. These are usually far and away the strongest part of the rigging.

In the last 20-25 years I have never damaged a shackle and I have ever seen anyone with me damage one either.

Mark...

Exactly, but even for e9999 this is way "over-thought" I worked as a rigger on a crane back when I was in college. We used shackles every day in every size to do our lifts. We were often using shackles that looked like they were made in the 1930's that were still working fine and as good as new. I have never seen a damaged shackle there, nor have I ever seen one in any 4 wheel drive application. Shackles which are rated are extremely strong, whith breaking strengths above 4 times the rated load.

e9999 is way more likely to blow his 80 series headgasket today, than to damage a shackle in his entire 4 wheeling career.

 

[e9999]

Exactly, but even for e9999 this is way "over-thought" I worked as a rigger on a crane back when I was in college. We used shackles every day in every size to do our lifts. We were often using shackles that looked like they were made in the 1930's that were still working fine and as good as new. I have never seen a damaged shackle there, nor have I ever seen one in any 4 wheel drive application. Shackles which are rated are extremely strong, whith breaking strengths above 4 times the rated load.

e9999 is way more likely to blow his 80 series headgasket today, than to damage a shackle in his entire 4 wheeling career.

Indeed, it is true that shackles are easy to get and inexpensive enough for ratings that may readily exceed other components of the rigging. However, I have also seen guys using marginally strong shackles and improperly at that. Plus, why not take the safer route if all it takes is a few $ and a second to put washers on. There may well be a defect in the shackle for all you know... Ironically also, the bigger the shackle, the more likely it is to get cockeyed when used.

Your typical shackle is 3/4" (I use bigger), that's about 6.5T IIRC. So 13Klbs WLL. Let's say you use it with a M12 double lined, and it's cockeyed at the block. You need at least 24K lbs strength. Breaking strength is something like 39-52K. If the strength is decreased by, say, 1/3 - 1/2 (don't know, but would not be surprised) cuz of the misalignment, say, that would make it close...

 

[Ian Rogers]

24Klbs what are you pulling out a Sherman tank, what are you going to anchor your 80(truck) to.

 

[spressomon]

Oh my!

 

[e9999]

on a related note, it is always bugging me when I see that people are relying on the built-in safety factor to use equipment that has an insufficient WLL... Yea, yea, you can rationalize that WLL is more for dynamic loads, hoisting, not static etc, still it's poor practice IMHO...

 

[fj40charles]

I think it would be better to design the clevis mount so that there is not any slop. I don't like the idea of having to fumble with washers in the rain, mud, or cold.

 

[Brentbba]

....an engineer at his very best!

 

[e9999]

I think it would be better to design the clevis mount so that there is not any slop. I don't like the idea of having to fumble with washers in the rain, mud, or cold.

Interesting idea. I suppose one could also design a shackle bolt with a narrow waist in the middle. Would have be thicker than now on the sides, though. I imagine they sell spools of sorts that would do the centering too, but you still have to thread it on. Easier, though.

 

[cruiser88]

guy got killed at a plant that i worked at for improper use of a shackle.

 

[cruiser88]

I think it would be better to design the clevis mount so that there is not any slop. I don't like the idea of having to fumble with washers in the rain, mud, or cold.

after the accident they starting using clevis more,including giving us a bunch and for the record it was wintertime when the shackle failed

 

[lx450landcruiser]

if your worried about breaking a D ring then id like to see the bumper your mounting the d rings to. Youll break your bumper mounts before you break a shackle

 

[e9999]

....an engineer at his very best!

can't wait to see what a Cruiser would look like if it were designed by a team of accountants and Lawyers....

 

[2badfjs]

why not just put the washers on now and leave it that way?

i understand

 

[Beowulf]

e9999999999,

We need pics.


-B-

 

[GeoRoss]

Maybe a force diagram as well.