Finally figured out why my load was spinning on every pick

Been running a crawler crane on a job in Biloxi for the last 2 months. Every time I lifted steel beams they'd twist like crazy. Tried adjusting my tagline tension and even switched to a spreader bar. Nothing helped until an old operator told me to check my hoist drum. Turned out the cable was spooling slightly off-center from the first layer. Took me 20 minutes to respool it evenly and now every lift is dead steady. Has anyone else had this issue or am I just slow to catch on?

2 comments

2 Comments

paul_thompson6723d ago

Interesting point on the fleet angle thing. Did you actually measure the angle between the boom tip sheave and the drum centerline as a specific number, or just eyeball it until it looked right? Been wondering if there's an accepted tolerance on that for crawlers of different sizes.

smith.jordan23d ago

Hang on a second, I gotta push back a little on that. In my experience, off-center spooling on the drum is just one possible cause, not always the main one. I've seen that happen a lot with new cable too, where it's got a little memory from the spool and it doesn't lay right until you work it a bit. Also, if you're running a crane with a grooved drum and the cable's a couple sizes smaller than the groove, it'll walk all over the place no matter how perfect the first layer is. Your mileage may vary, but I'd say check your fleet angle too. If the sheave in the boom tip and the drum aren't lining up just right, that'll twist the cable and the load before you even start. That's worth looking at next time.