Call hot line or utilities to avoid lines.
-
the power auger , if they get stuck, will whip around and break your ribs.

either a nozzle on a garden hose, or a high-pressure sprayer.

might end up with a half made hole filled with water for a week or two

When I was a kid, my Dad leased land all over the county to raise his cattle on. Every one of those pastures needed to be refenced.
Guess who was tasked with that little operation? I must have run a 100 miles of barbed wire and thousands of posts while I was in Junior High and High School. When I was 15 I swore I would never buy a posthole digger. I'm 66 now and the only reason I have one is my brother wouldn't take it when Dad died.

1) If you're putting in metal posts, consider using a Post Driver. No need to dig.

2) You may find a Boston Digger a better tool for removing the dirt after using the digging bar.

One tool you could use if you don't mind forking out some money at a hire shop is one of those 2-stroke post hole borers.I've used one before doing a retaining wall and it made the job some much quicker and some versions can used by one person.

As someone said earlier, if you hit hard spots you could lose control and it could hit you pretty hard. I had a similar experience on a much smaller scale with a drill with auger bit … I needed to punch a small hole into my clay soil to stick a ruler for measuring snow. Wow. The force of hitting something hard can be quite violent, even for a drill. For a borer, it would be really scary.

It works good in decent soil. In dry red clay, or red clay just damp enough to stick together good, it's useless.

One dry year we needed to run a new fence line so we took the tractor out with the borer on it. Generally I drove the tractor while my husband guided me and monitored the auger. The first hole, I dropped the auger, revved up the tractor and tried to bore out the hole. All it did was make a polished divot in the bone dry clay.

So my husband decided it needed some extra weight to bite in and he climbed on top of the auger. Now, he weighed about 250 so we both expected it to make a difference. The divot got shinier. I set the brakes on the tractor and climbed up on the auger, too - I won't discuss my weight but it added to the pressure. Nothing, but a really shiny divot in the clay.

We gave up and dragged a soaker hose along the line for the new fence and left it going for two weeks. That and a couple of showers moistened the ground enough we could get the holes dug, but it was still a battle.

From watching videos of how to use it, it appears that you have to thrust it into the ground with some force and aim it just right. I have clay soil with rocks in it, and I don't have a lot of muscle strength so I'm a bit intimidated by those clam shell post hole diggers.

I bought a slightly different type of post hole digger that is a bit easier to use. I dug a shallow hole, about 1 foot, for a plant support pole, and liked it. It's got a twisted auger-like shape that cuts through the ground. I've not tried it yet for digging deeper holes.

http://www.amazon.com/dp/B00002N8OK/ref=pe_385040_30332190_TE_M3T1_ST1_dp_1

Our property was filled with construction debris which we did not discover until attempting to plant trees and shrubs. I have dislodged large chunks of asphalt, concrete, rebar, animal bones and enough rocks large and small to build a second house (if I were inclined to). My digging bar has the chisel end and a pointed end. I've dug up the root balls of numerous small trees, shrubs and grape vines.

That said, the backyard fence is in bad need of replacement and we are very likely going to let the pros take care of the job.

and get rid of all sorts of problems that would stop the project.

They can also be used as a very strong lever for other jobs. A great tool for just $35. Now that I have one, I'll find many uses for it, over time, I'm sure.

rocks mixed in. Not so well at all.

This is really a hard job and I wish you the best of luck. I have worked digging holes by hand with such tools before and man it is tiring. Coming upon a rock is extremely difficult sometimes, but a bar is the only way to get it out. I usually start digging the hole, only a couple of inches and add water. I then go to the next hole and do the same. After some while I come back to the first hole and the soil is very easy to take out. Sometimes the mud in my soil just comes out like water and other times it does stick to my hole digger, but it is not hard to get off either You do get all dirty and muddy, but you will certainly not have to use as much strength .. Again good luck on your hole digging.


Regards
Rod
North Carolina Septic Systems