Observatory Construction: Excavation
I hired an excavator to both prepare the building site and dig a 400 foot trench so that electrical service could be brought to the building from the utility pole. The latter proved to be quite an adventure because after the first 100 feet, we found that it was impossible to continue digging - despite the power of the excavator's trackhoe - because the solid bedrock underneath the rocky soil was quite shallow and impossible to break apart.
The electrician confirmed that digging only as far as the bedrock would result in insufficient depth to pass inspection. The solution was to blast the trench with dynamite! So, I hired a company to do just that. A giant drilling rig was brought in, and 112 holes of approximately three inches in diameter were drilled deep into the bedrock. This took an entire day.
The next day a crew arrived and 112 charges were set in series. We cleared the area, and when all was set: Boom! (See Quicktime movie on right.)
I was somewhat disheartened at first by the result, as the nice road I had cleared to the building site was now under a large pile of rubble. But the excavator was able to clear the rock and use it to line the driveway, and the conduits were buried according to plan.
Observatory Construction Pages