The speed of drilling the two foot wide hole through very hard rock in Chile is due to this drill from Center Rock Inc. of Pennsylvania.
Each of several drill bits clustered in the canister have air hammers behind them. Very fast and powerful. Sizes range from 20” up to 120” in diameter. Company news piece here.
“When we saw that they were talking about Christmas, we immediately started looking at the technology they were using. That technology is fairly antiquated compared to what we had. We got hold of the right sources and contacts. … We felt we could drill it quicker.”
The moment the drill broke through, “I tell you, it was pretty exciting. There were a lot of grown men in tears.” [link]
