Picked up a trick from an old timer about tensioning boom cables

I was waiting for a load the other day and overheard a guy say you should always tension boom cables when the crane is cold, not after running it for an hour. He said the heat from the hydraulics and sun expands the metal just enough to give you false readings. I tried it myself last Tuesday on a 50 ton Grove and the difference was about 1/4 inch on the slack side. Now I always do my checks first thing in the morning before coffee. Has anyone else found this helps with cable wear over time?

3 comments

3 Comments

coleman.jade7d ago

Read a crane manual that said hydraulics pull heat from the engine block.

wesley_grant3323d ago

Man, that is a solid tip right there. I never thought about how the heat could throw off the reading like that, but it makes perfect sense now that you mention it. That's a bummer about your initial tries though, a quarter inch is a lot of play to miss. I gotta say, I admire you sticking with it and figuring out the right pressure for your setup. Is there a specific cold pressure you aim for, or do you just go by feel until it doesn't sag?

ivanlewis23d ago

Man, you're onto something bigger than just cranes there. I noticed the same thing with my truck's tire pressure. Check it after a long drive and it reads high, but let it sit overnight and it's actually low. Same with how my guitar strings go sharp after playing for a while then settle back down when they cool off. Seems like half the stuff we own is lying to us about its real state until it's been sitting for a few hours. I bet that old timer learned that lesson the hard way too, probably had a cable snap once or twice before he figured it out.