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Warning: That new synthetic sling on the job in Spokane failed way under its rating.
We were lifting a 12-ton HVAC unit last Tuesday, using a brand new 5-inch synthetic. The tag said 20-ton capacity. It snapped clean at about 8 tons, dropped the load maybe 3 feet. The rigger swears the angle was fine and there were no cuts. I think the cold morning, it was maybe 28 degrees, did something to it. Has anyone else seen synthetics get brittle like that in the cold?
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reed.ray10d ago
Yeah, Simon's totally right about the charts. I mean, that derating can be brutal, like you're only allowed half the load or even less. It's not just about being cold, it's how long it sits in the cold before you use it. A sling that's been in a freezing truck bed all night is way worse off than one you just brought outside. The tag rating is basically useless if you don't know the temp rules.
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simonm6710d ago
Whoa, that's a scary failure. I read an article last year about synthetic slings and temperature ratings. Some of those flat web types lose a HUGE amount of strength when it gets below freezing. The tag might show the warm weather capacity, not the cold one. You gotta check the manufacturer's chart for the derating factor. That morning was definitely cold enough to cause a major problem. Glad nobody was hurt.
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