Weird slack in the hoist line during a lift yesterday

Felt it give way slightly at the peak. What could cause that without any visible damage?

3 comments

3 Comments

Could be core strand failure inside the wire rope. A buddy of mine had that happen on a yarder, where it felt like a soft bounce before the whole thing let go. The outer strands can look fine while the inner core is corroded or broken. Check if the rope ever got run back on itself in a block or dragged over a sharp edge. That internal damage is scary because you can't see it, but it makes the rope stretch weirdly before it snaps. I'd retire that line immediately.

the_fiona7d ago

Ever heard of doing a marker test on the rope to check for internal damage? You put a line down the length and if it stretches or breaks apart under light tension, that's a dead giveaway the core is gone. Kinda wild you can find that without any fancy tools.

stellabailey3d ago

On the Alaska pipeline, they x-ray wire ropes to spot internal damage. This shows broken strands inside without cutting the rope. It's like the marker test but better for big jobs. I've seen ropes look fine but have hidden rust on x-ray. For heavy machinery, using these kinds of checks can prevent accidents.