Trenches can be very dangerous - dirt weighs over 100 lbs per cubic
foot, so a cave-in in even a shallow trench can be deadly. If you
are over your head in a hole that isn't properly prepared/shored you
are taking your life in hand. The links below provide some insights
on this. If you're going to do nothing else to protect yourself, you
should never put loose dirt near the edge of your hole, as indicated
below it can flow back in.
We're doing a large expansion at work with a 20' deep hole, the
excavating contractor spent as much time preparing the side walls
(3:1 setbacks, compacting soil, etc) for safety in the hole as they
did removing the dirt. Even with this preparation, we selectively
shore areas during some work activities to further protect the workers.
http://www.trenchsafety.org/trench/sample/buriedalive.html
http://ohioline.osu.edu/aex-fact/0391.html
Gregg
KI3G
At 02:51 PM 12/3/2007, Roger (K8RI) wrote:
>Many years ago we needed to cleanout the weep tile around the basement.
>Those who've seen my tower construction project photos know this area is
>heavy clay.
>
>The crew dug out a strip all the way across the back of the house down to
>the bottom of the foundation. (That's deep). They came inside to tell me the
>work was finished and would I like to take a look at it. When we went out
>there as a trench about 5' wide and about 2' deep. They had not dug out all
>the back fill which was sand. Fortunately no one was in the trench when it
>let go, but there were some long faces thinking about having to did all that
>out again. The next time they dug it all the way out to the clay. BTW they
>never did seem to realize what could have happened had they still been down
>there and not in a hurry to show me the progress.
>
>Recently we added a egress window and were redoing the basement walls which
>had some bad cracks. This time I had a contractor come in and they dug
>around the entire basement using heavy equipment much to the dismay of my
>yard...and wife. It's an old basement so they straightened the walls and
>reinforced them by putting in rerod and pouring the blocks full every few
>feet.
>
>I took this opportunity to move the conduit bringing the coax into the
>basement from going through the basement wall to going into a NEMA 4
>enclosure. From there it comes straight through the end plate. It's more
>convenient to work on and would be much easier to cover up some day. The
>trench is shown in the last photo on
>http://www.rogerhalstead.com/ham_files/cablebox.htm . One of the
>construction crew is coating the basemnt wall after they had put in new weep
>tile. He was a big man so it gives a good reference as to the size of the
>trench. This page has a number of photos so it might take a while to load.
>
>73
>
>Roger (K8RI)
>
> >
> > Can confirm that. Just last week the local news focussed on a rescue of
> > a worker, from what appeared to be about a 5 ft hole, whose walls
> > collapsed on the worker standing inside. The on scene camera showed the
> > extraction, and the report said that the victim became unconscious.
> > This, even though the cave in only packed him in up to about his
> > waist. He survived, but it was obvious from the pictures that it
> > took a lot of rescue expertise and equipment, Jacks, wall support
> > boards, power digging gear, and significant time to make the rescue.
> >
> > All the Best, 73,
> > Pat Barthelow aa6eg@hotmail.com
> > http://www.jamesburgdish.org
> > Subscribe: http://bambi.net/jamesburg.html
> > Jamesburg Earth Station Moon Bounce Team
> >
> >> Date: Sun, 2 Dec 2007 20:52:51 -0800
> >> From: pyoung47@yahoo.com
> >> To: TowerTalk@contesting.com
> >> Subject: [TowerTalk] Be Careful
> >>
> >>
> > One needs to use some caution working in holes of the depth for the
> > crank up towers. Cave-ins can be dangerous even for depths like that.
> > If you happen to be bending over and the dude comes in you may have
> > literally dug your own grave.
> >
> >
> > All the Best, 73,
> > Pat Barthelow aa6eg@hotmail.com
> > http://www.jamesburgdish.org
> > Subscribe: http://bambi.net/jamesburg.html
> > Jamesburg Earth Station Moon Bounce Team
> >
><snip>
>
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