This video was recorded at Park Ave. Elementary in Des Moines, IA. Our mission was to get two- six inch geothermal header lines (supply and return) into a utility tunnel beneath the school. The shot wasn’t very long but we had very limited room to work and tight tolerances. We first needed to drill thru a six inch thick concrete footing and then an eight inch thick cinder block wall to get into the utility tunnel. Then, we had to open up the pilot hole to just over eight inches using a reamer. The job specs required that the bore be at least four inches off the floor but safely below the electric conduits that were running about 16 inches above the floor. Our next issue was that the tunnel was 3 inches narrower than we needed to be able to take our drill head off and put on the reamer. So, we decided to drill three inches into the opposite wall to give us enough clearance. As you watch this video, I apologize, the lighting was not very good for the first bore but it was much better for the second. If you’re curious how the pipe got into the tunnel, after we cut the hole bigger we pushed the pipe thru the hole from the outside then the mechanical crew fused the flanges on as soon as the pipe was inside.
Drilling into a Manhole.
This video was recorded on the West side of downtown Des Moines, IA. We needed to bore a two inch conduit into a manhole in the middle of the street. We have drilled into many manholes before, but this particular one was different. The only open spot for us to drill into was a spot roughly five inches in diameter. Since our drill head cuts just over a four inch hole we essentially had to be dead on the first time. To give you some detail, what you will be looking at (from the top down) is the manhole with a cast iron sleeve, a concrete riser ring and the top of the sewer box. I have a white paint mark on the spot where the head needed to come in.