Had a close call with two different load charts on a job in Phoenix

We were setting HVAC units on a roof last month, and I had the old paper chart for the crane in my cab. My spotter pulled up the digital chart on the company tablet. The paper one said we were good for 8,500 pounds at that radius, but the digital version, updated after a boom repair, showed 7,200. That's a 1,300 pound difference we almost missed. We went with the digital chart and the pick was smooth, but it was too close. How do you guys make sure your load charts are the right version?

4 comments

4 Comments

taylor.jessica1mo ago

Man, that's scary. A buddy of mine had something similar happen with an old crawler crane. His crew was using a laminated chart from like three mods ago, but the main office had sent an updated PDF after they swapped the hoist line. The weights for a pick at max radius were off by a ton, easy. They only caught it because the new guy called to double check something. Now they have to initial a sheet with the chart revision date before any big lift.

paulnguyen1mo ago

That's a close call, taylor.jessica. A ton off on the chart is no joke. It's wild how something as simple as an old piece of paper in the cab can cause a disaster. Good on that new guy for speaking up, that's the kind of thing that saves lives. Makes you wonder how many sites are running on outdated info right now.

max_schmidt771mo ago

A laminated chart from three mods back? That's insane they were even allowed to keep it on site. How does a main office send a PDF and not make sure the old hard copy gets destroyed? The initialing thing is smart, but it shouldn't take a near miss to get that basic process in place.

noahwood9d ago

Dude that is exactly the kind of thing that keeps me up at night! I had a similar close call back in '21 with a Grove crane, the paper chart in the glovebox said we could reach a 12k pound transformer but the digital one from the rental yard said 9,800. We were one swing away from picking it when my operator buddy checked the serial numbers on the boom and realized the old chart was for a different boom configuration entirely. It's insane how easy it is for those old paper charts to hang around like ghosts in the cab. The rental yards need to get better about collecting those old ones or stamping them VOID the second a repair is done.