On Apr 4, 11:31 am, Jim Elbrecht wrote:
RicodJour wrote:

[vacuum excavators]

-snip-



But they are becoming more available at rental yards and they
certainly have a lot of advantages. Some of the machines have a
reverse flow feature where the excavated material can be deposited
elsewhere on the site or in a truck/dumpster so the machine can keep
going.
http://www.constructionequipment.com...occlamp&articl...

Got a video of one in action? I've called a couple rental places &
haven't found one to look at yet. [near Schenectady, NY]

Nope, I don't. Try YouTube or one of the manufacturers' sites.

But this might be the answer to my '10' trencher' question I asked
about on a.h.r a couple weeks ago.

I don't need fast- but I need to dig a 10' long horizontal hole about
4-6" in diameter- then 'elongate' the hole vertically down 7-8 feet.
The soil is hardpan clay.

I'm not sure I understand you. You have to dig a small diameter hole
that extends 10' horizontally then go down 8' starting at the far end
of that hole, or are you saying you have to trench 8' down the whole
10' length? The first one sounds borderline impossible, the second
one _might_ be possible with the vacuum excavator if the soil
conditions are right, but I think that you'd still end up collapsing
the trench as you went due to the vibration.

R