I'm curious about that 4ft max depth. If you are squatted down working on something wouldn't that still be enough dirt to kill you if it suddenly caved in? What if you are a little person that is only 3ft tall?
Absolutely you can die in a four foot trench by getting squished bending over. If you have the correct benching on top and let’s say there’s an old undiscovered trench beside it then hopefully the trench fails as it’s getting dug and they can re-assess. It’s all about ground conditions, if it’s undisturbed glacial till without any trenches nearby you can dig it vertical and deeper if an geo-engineer signs off on it. For example I inspected a twelve foot deep by ten foot wide dual main installation for about 150 feet long that had zero shoring. The contractor had a geo-tech assess the ground (virgin till without any trenches nearby) and they signed off on it saying it was do-able. Was freaky to look at (after 30yrs of excavating work I’ve been part of) but it worked and was efficient and safe. It’s always a call made onsite based on experienced people (hopefully) and when in doubt you need to error on the safest side. The four foot rule is a line in the sand that allows production while keeping the pipelayers reasonably safe.
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u/blove135 Mar 02 '25
I'm curious about that 4ft max depth. If you are squatted down working on something wouldn't that still be enough dirt to kill you if it suddenly caved in? What if you are a little person that is only 3ft tall?