Can You Point to It?
Critical thinking skills are essential for safety management. The question being posed in this article involves critical thinking skills, asking, “Can you explain how you arrived at a particular conclusion?”
Let’s look at a few common misconceptions that can easily be cleared up by putting this into practice.
Misconception #1: All previously disturbed soils are to be classified as Type C according to Appendix A in Subpart P.
The response: Nowhere in Appendix A can someone point to any place where it says previously disturbed soils are to be classified as Type C. It does say that previously disturbed soils cannot be Type A. But the words “previously disturbed” are not found in the definition of Type C soil.
Additionally, in the federal register where the topic is explaining the definition of Type B soils, it specifically states that most disturbed soils are Type B.
So, there is no place where someone could point to and say, “It states here that previously disturbed soils are Type C”. There is no basis for that conclusion.
Misconception #2: “We consider everything as Type C soils, so we bench all of our excavations.”
The response: When using Appendix B of the OSHA Excavation Standard, there is no allowance for benching Type C soil. The worse soil that can be benched according to Appendix B is a cohesive Type B soil.
Misconception #3: “Type A is good soil. Type A will not cave in”.
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The response: First of all, Type A is a very good soil, but that doesn’t mean it’s safe. It just means that it is easier to make a Type A soil safe than Type B or Type C.
In OSHA’s Appendix B for sloping and benching, there are sloping and benching options for Type A soil. If Type A won’t cave in, there wouldn’t be any of these options.
In OSHA’s Appendix C for timber shoring, there are two charts devoted to options for Type A soil. If Type A won’t cave in, there wouldn’t be a need for these charts.
In OSHA’s Appendix D for aluminum hydraulic shoring, there are charts devoted to shoring options for Type A soil. If Type A won’t cave in, there wouldn’t be a need for these options.
In most tabulated data for shoring and shields, there are specifications devoted to dealing with Type A soil. If Type A won’t cave in, there wouldn’t be any of these options.
I could go on, but I’ll close with this one. In OSHA’s Appendix F’s flow chart for protective system, the only soil type listed that won’t cave in is stable rock. If Type A won’t cave in, it would be included in the chart alongside stable rock.
The overall point of this brief discussion is, can you point to the standard, tabulated data, or the federal register to support your position on any given excavation safety topic? If not, some research should be in your future.
For more information on principles of Excavation Safety we invite you to visit www.trenchandexcavationsafety.com
Branch Manager at Trench Safety Rentals - A division of Sunstate Equipment. (Formerly Trench Shore Rentals)
4 个月Thank you for this! In our region of the southwest Myth #2 is the most common. A popular misconceptions about “C” soil and the ability to bench “C” soils as a safety measure. A contradiction of sorts that is commonly accepted.