Yep fair point, but the stress would be minimally different.GU_247 wrote:Brad
The way your shackle is in the recovery point allows the pin to bind. Irrespective of whether the rating of the shackle is well above the requirement you should allow this to happen. I do agree that the majority of people have their recovery points set up this way but we are now talking about a vertical lift. In the case of lifting with 1 recovery point I dont see there would be too much issue, However I would assume that the recoveries will make use of both recovery points on the front or rear of the vehicle causing the chain to triangulate (as per thunders image).
This causes the pin to bind or worse spread the legs of the shackle. The load should be on the pin, not on the legs where the pin passes through. To correctly do a vertical lift with the pin in the recovery point, the axis of the pin needs to run in the direction front to back along the vehicle. but this obviously wouldnt allow a horizontal recovery.
The design of the bow shackle allows the bow end (not the pin end) to to take a load in multiple directions.
I dont proclaim to be a rigger but I design heavy machinery in excess of 10T where lifting points need to be considered.
Whether youre lifting 50kg or 20T the same principles should be applied.
Paul
But it's still going to be pulling on a angle between the two points, only difference is less binding.
I'm not disputing adrenalin's points have slightly less load on them, but more to the point that it is still over engineered.
Having my points welded on would be much stronger again.
In my case my truck weighs a max of 2T
So that's approx 600kg each front point and roughly maybe 400kg each on rear, then it depends if it was stuck in mud or weather it's leaning to one side.
Either way with the pins binding its still overkill and safe.
A 12mm 12.9 grade bolt (that I have used) is rated to around 10T depending on the load being applied.
Brad