These are small tractors with sealed video camera w/lamp that are placed
into 4" - 6" sewer pipes for the purpose of locating breaks or cracks.
They are put into the pipe at a manhole and can run as far as 600' to
the next manhole. As the cable pays out, it locates the distance from
the manhole. When the break is seen by the operator, the type of break
and location is noted so a crew can later dig down to the pipe to patch
it. What are they looking for? breaks, because the sewage leaks out? no,
because the sewage is thick, it rarely leaks much; but groundwater
getting INTO the sewerline causes a dramatic increase in the burden of
the treatment plant downstream.

Interesting? yes, but very dirty work. The chemicals in sewer pipes are
not only nauseating, they are also capable of dissolving steel and/or
plastics easily. Most robots have a stainless steel case, but even that
can eventually corrode through.

But it's also very lucrative. Operator-owners get as much as
$10USD/running meter for a well-documented videotape of sewer line
breaks. I have met several gentlemen who are millionaires several times
over that have done that for ten years. And don't count the number of
operators in gold country that find gold flakes accumulating at the pipe
crack, or find diamond rings flushed down the toilet and trapped in the
pipe... Those diamonds sparkle like the sun when the light shines on it,
saw a videotape of a find once...

--Bob
--

Replier: Most attachments rejected
       --------------
         Bob Axtell
PIC Hardware & Firmware Dev
   http://beam.to/baxtell
       1-520-219-2363

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu