Saw this huge drill outside the office this week. I know this construction effort involves an underground passageway from our building complex to the subway station, but I can't quite figure out why they're drilling such deep holes. Anyway, it is a cool machine to watch in action. And MUCH quieter than the pile driver I once had outside my condo window in Hawaii.
It wasn't actually running in this photo, but I've seen it in operation earlier. It was interesting to see the dirt riding up the drill bit and falling out to the ground. In the photo below, there's a closeup showing where the dirt falls down a chute.
This is just like a hand drill, but on a much larger scale. And for whatever reason they're drilling, they're making several holes. They are moving this drill around the site and preparing lots of holes. I'll just have to wait and see what develops.