Just realized my load chart was off by 300 lbs on a job last month

Ngl I was looking over an old job in Detroit where we were lifting a 4 ton HVAC unit onto a roof. Turns out I was reading the chart for the wrong boom angle and nearly exceeded the safe limit by 300 pounds. I found the mistake when I double checked the manufacturer's manual from 2022, not the worn out one in the cab. Has anyone else caught a chart error that could've been bad?

3 comments

3 Comments

wright.lisa23d ago

Wait hold on, a 2022 manual? Those load charts are usually stamped right on the crane or in the cab for the specific serial number. Using a general manufacturer manual from a different year could have different revision numbers or corrections that don't match your exact crane model. Been there before. Check the actual sticker on the boom itself if it's still readable, sometimes those get painted over or faded. Also worth verifying if the 2022 manual supersedes the one in the cab, sometimes the cab chart is the correct one if it was updated after a recall or re-test.

briancarter23d ago

Respectfully @wright.lisa, I gotta disagree a bit here. Most OEMs put the actual serial number specific chart in the cab and the general manual covers a range of models, so the cab sticker is king for that exact machine. But if someone has a 2022 manual that covers their specific serial number range, the manufacturer probably put that revision out for a reason like a corrected capacity or a new test. I've seen too many old stickers get painted over or swapped wrong to trust them completely without cross checking the latest revision.

morgan.logan23d ago

Funny thing, I once spent an hour arguing with a foreman over a load chart only to realize I was reading the one for the wrong boom extension the whole time. Cab sticker turned out to be right, but my eyes were definitely not. Pretty sure my embarrassment is still on a safety board somewhere.