Even in granite-like conditions the new Cat MD5150C top hammer drill is out-performing down-the-hole rigs with its higher productivity and much lower fuel consumption — while achieving comparable hole straightness, according to the manufacturer.

Beyond feet per minute, the cost per foot is a clear winner, too. At Iron Mountain Quarry, St. Louis, Mo., the MD5150C drills 5.5-in. (14 cm) diameter holes to 70 ft. (21.33 m) deep using 68-mm-diameter drill rod, commonly called drill steel. The bit can last 1,100 to 1,200 ft. (335 to 366 m), which is the same consumption rate as the previous down-the-hole drill. Fuel consumption, on the other hand, is much less. Further, the drill steel experiences less wear and long life. Owning and operating cost for the Cat machine is lower with the simple rock drill design, which can be serviced in the field, according to the manufacturer.

Matt Jacobs, Cat Drills commercial manager said, “We saw similar results in an earlier trial at a Tower Rock limestone quarry near St. Genevieve, Missouri. That site has softer rock conditions and the MD5150C dramatically outpaced a DTH drill. Austin Powder conducted a bore tracking test and the results showed a hole deviation rate with the MD5150C top hammer drill that was within the desired range. Tower Rock Quarry was very pleased with its higher production and lower operating cost — all while achieving similar hole straightness.”

For more information, visit www.cat.com.