Cave Ins

[Pole Cat]

This is a question for some of the more experienced , or not so experienced , privy diggers out there. As a Lineman for the county , so to speak , I am often trenching in new service cable for electrical services . The Industry being what it is today , I am often taking courses on safe trenching which includes learning about soil types . compaction , and when it is safe to go into a trench as the forces and weight can kill a man quite easily in the right conditions . I have had no experience digging privies so I do not know whether they were shored up regularly or not. Have there been privies which you have walked away from due to instability? How would you shore one up if it needed to be shored up ? At work , if its over 3' deep we have to use a trench cage or open it up by 45 degrees so that the straight depth is back down to 3'. Just curious as most of the digs I have watched on you tube looked quite deep and confining.I look forward to your comments.Thx

 

[appliedlips]

Good questions, privy digging is dangerous and care should be taken while digging them. I personally hqve walked away from several holes and have taken the time to shore others. Soil types and the construction of the walls are both important in determining safety of a hole. For example I feel very safe digging a round brick or stone lined hole dug in undisturbed clay. The round shape locks walls in place and makes for a very strong structure. On the other hand a woodliner in sandy or gravely soil can be very risky. From my understanding even a lined hole that is oval or a trench like rectangle is more susceptible to cave in. The longer the straight walls are the more dangerous. Holes that have been disturbed by later construction work can also be unstable. I think the most common cave ins occur from diggers tunneling or not cleaning the fill above them,wall to wall as they dig. I have even been guilty of this,but try to be more.safety minded these days.

 

[cadburys]

...not much more to add other than what appliedlips has already said. When it comes to privy digging there are no courses to go on which teach us about compaction and soil types. That being said, the experience we have gleaned over many years of digging tends to be our educator and tutor.

In my experience (which is about 80 pits) instability has only occurred when you get into the use layer and you start digging that all too familiar bell shape to get to the bottles around the perimeter, It is not the soil, but rather the fill which is prone to collapse.

Hopefully common sense prevails over excitement when we get down on our knees when 6ft down in a hole!

Ant

 

[RICKJJ59W]

That is it in a nut shell. The fill in the privy must be dug out evenly as you go down. Do not leave a mass of fill ash,dirt,brick,etc on the walls,we call that cheating. Soon that mass will be over you and can come down at anytime. I have never had a "natural clay" wall,brick liner or stone liner cave in,but I have had a close call with "cheating" Its the fill that will kill ya as Doug said. Dig it all out.

 

[nhpharm]

Down here most everything is wood-lined and the early ones are "Barrel Privies". Tops usually about 5' below ground, bottoms 9-10' down...sometimes more than one barrel stacked. These barrels can be very bad...they almost always collapse inward while you are digging them and the soil outside them is rarely self-supporting.

 

[Pole Cat]

I will soon be looking at my first privy dig. I recently obtained permission to look and dig out any privies I might find in the oldest bar in my area which places it around the early 1900's. Not the 1800's stuff I see some of you guys digging but hey , you work with what you got. This is in Canada too so another thing to watch out for is what the frost heaves have done over the years and most privies that I have seen are wood lined. Thx for the great advice all. I do have a two piece culvert made out of thick galvanized steel . It is about 6' long with about a 4-5' diameter.I might have to lower that from a tripod setup as the dig continues.Life does seem to get in the way of my digging so who knows when this project will actually get going. This working for a living has got to go.LOL