Hello, All, Can anyone point me to specific OSHA standards that outline crane operation near excavations? I am trying to come up with a company standard on distance from outrigging to excavations and trenches. Thanks for the help!
There is no such specifiec standard in OSHA. OSHA does not get to specific about hardly anything. They only say that it's your responsibility to insure that the footing you are on is adequate to support the machine and load. It would be impossible for them to be specific on your question. On hard rock you could be completely solid right at the edge of the hole. In loose soil like a peat based product you could be on mats 50 ft from the excavation, and the whole works could slide. A registered soils engineer is truely the only one who can tell you what is safe for any given weight.
Thanks for the response, old-iron-habit! Yes, looking through OSHA it does appear as it is in place to provide more general guidelines. I did find a resource out of Queensland, Australia which provides certain rule-of-thumb guidelines for crane operation near excavations: http://www.deir.qld.gov.au/workplace/resources/pdfs/mobile-crane-cop-2006.pdf Also, a good reference book that includes a discussion of cranes near excavations is the following: Shapiro, L. K., & Shapiro, J. P. (2011). Cranes and derricks (4th ed.). New York: McGraw-Hill.
The problem with rule of thumb is that when the rule doesn't work someone gets killed or at the least damage is done. There is a fair amount of chatter on this site about when safety officials try to neatly package up rules on things they are not experienced in, then expect a expert in the field to follow them. No offense meant but I hope you are not one of them.
Correct. I understand that a rule-of-thumb doesn't always apply, but for standard lifts on highly compacted and well drained soil it seems like these rules-of-thumb are appropriate. In any case, you are right, a certified expert in the field's input is certainly important and shouldn't be over-ruled. My goal isn't to throw away the knowledge of experienced field engineers, but to provide a preliminary guideline for standard lift plans.
Might look at the Angle Of Repose of the given soil type of ground the crane is setting up on . http://en.wikipedia.org/wiki/Angle_of_repose In my area on stable clay soil we set up behind the 45 degree mark . If the excavation is 4 foot deep the outrigger cribbing is set up behind 4 foot line from the edge of the excavation . As old-iron-habit said ... Pretty hard to set a standard for every situation . Oh yeah .. Amount of cribbing also comes in to the equation .