Let me start by saying, I'm pro safety. I love oversight. I started a blog on tower crane accidents over a decade ago because I thought people should see the reality of poor decisions and what those decisions were. I was a crane inspector working across the US. I participated in the writing of the codes Washington uses today and myself and a tower crane engineer wrote the test the tower crane inspectors have to pass today in Washington. Most of this work was unpaid. I'm pro safety at that level. But I want to talk about where it can go too far.
OSHA 1926.251 requires everything below the hook
is tagged and rated. Then it goes on to say that "Special Custom Designs" have to be overload tested to 125% of that rating. This applies to one off designs. Designs that are manufactured do not fall under this rule. They should be tested once or as a sample process at the factory. Then you build the same product to the same spec and all should be well. Think of crash tests and cars. We don't crash each car to prove the engineering again. The problem comes in our consensus standard, ASME B30.20. It requires a load test of 125%. This is fraught with hazards and could lead to serious complications.
Most of the European trash bins these days have large capacities. 4 yard bins have 13,230 lb capacities across many manufacturers. What are you putting in there to hit that 125% capacity? How about a concrete bucket. It is designed to take the volume needed and capacities are just above that (not including a significant safety factor). So a two yard bucket with a 8400 lb rating needs to be tested to 10,500 lbs. But you can't fit that much concrete into it, and that's by design. If you go to lead shot, you would be at 28% of the cone filled. So now you have added pressure on the gate that is concentrated. The cone has little to no resistance pushing out or down above the materials. And we are to overload test this to 125%? If it goes wrong, who is responsible here? A person is trying to be in compliance, but they are endangering others with compliance in these scenarios.
OSHA did a Letter of Interpretation on this in 2004 that is clear, but it can easily be misread. The questions involved are with regard to load testing "Special Custom Designed" items and being in compliance.
Question (3)(b): Where manufactured (not custom-designed) I-beams with shackles (lifting beams) are not load marked, are we required to proof-test and mark them?
Answer
No. Section 1926.251(a)(4) applies to "special custom[-]design grabs, hooks, clamps or other lifting accessories." Therefore, it does not require manufactured lifting beams - that is, lifting beams that are not custom-designed - to be proof-tested and/or marked.
It's critically important that we don't seek to change this. You don't want to point load or load an item in a way the manufacturer didn't intend with oddball items. I am of the opinion that this is going too far and should not become a standard practice. It's not that it's impossible or 125% is too much. It's that it's complicated and should be well thought out. This is one of these points where we should be stopping the safety march. Do not adopt ASME B30.20 as a fully required code. Be specific that you don't require load tests when you are in stakeholder meetings. You really don't want this as a field practice. The math to figure out how to match the intentions of the designs are just too complicated to be a safely adopted practice in the field.
For reference: The products I sell are not only engineered by a company that has done it for 119 years, there is a third party (TUV) that reviews the process. The ASME safety factor is significant @ 3:1. The 100% rating is a real challenge to get to on most items. We should be inspecting them, documenting it and putting them into service. More is not always safer.
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