CDB60 Boom and 900 at Luck Stone Quarries
from our March, 2000 Issue

Over a decade ago, Virginia-based Luck Stone Corporation, the twelfth largest crushed stone producer in the U.S., made the decision to install pedestal booms and breakers to remove rock jams in their crushers. In 1997 they purchased their thirteenth such installation, choosing a Tramac 900 breaker mounted on a CDB 60 stationary boom. The commitment for the new equipment was preceded by a successful test period arranged by their dealer, Bill Daly of J.W. Burress in Roanoke.

Safety and Efficiency—Major Concerns
The reasons for installing the first boom/ breaker combination back in the eighties are still the major concerns today. First and foremost is the issue of safety. Prior to the stationary booms, jammed rock had to be cleared from the crusher by workers entering the crusher's pit to maneuver cables around the material so it could either be hoisted out or shifted to undo the jam – a dangerous, time-consuming process that also meant a lot of expensive downtime for men and machines.

What Prompted the Company's Move to Tramac?
Plant Equipment Manager Jim Herber, a 12-year veteran with the company who is responsible for all the company's stationary booms, was specific about what makes this particular Tramac combination right for the job. At the Haw River Plant, he said, "the application is breaking very hard granite. The power of the 900 hammer and the design of the CDB 60 boom make them very appealing."

In the case of the boom, it's the CDB's engineering that attracted his attention. "It's not the standard square boom design," Jim said, explaining the preference for Tramac's heavy-duty, reinforced box-section construction, intended to stand up to the stresses of constant rock application. He went on, "We like the structure and placement of the cylinders, and the more effective productive force." One operator runs both the crusher and the boom/breaker, using the latter only when needed to break up oversize material that can jam the crusher. "The hammer and boom operate between 500 and 600 hours per year, and we've been problem-free."

As for the hammer, it was the 900's power that made up Herber's mind, along with the design of the breaker's hydraulics and the vibration isolation feature (standard in Tramac medium and heavy breakers). "The hydraulic design is superior; the valves are high quality, easier to work on, and more durable. The rubber cushion above the hammer isolates the vibration in the hammer, and absorbs shock that would otherwise travel into the boom, which is important when you're breaking such hard material." Luck Stone has had no difficulty with tool breakage and practically no down time.

Luck Stone uses high production Tramac breakers (V53s and V42s) on their mobile carriers (Komatsu carriers PC300-6) to break up oversized material produced by blasting. The breakers take the large material down to a size that can be handled by the crushers. According to Paul Hayes, who oversees the mobile breaking operations, operating expenses on competing breakers were too high. With the Tramac models, less maintenance is required and they are able to reduce cost further – and increase output – by mounting larger hammers on smaller carriers.

Luck Stone, a family-owned business based in Manakin, Virginia, was founded in 1923 and owns 17 locations in Virginia and North Carolina. This includes 14 quarry sites – mining primarily granite, as well as diabases, limestone, and basalt – and 3 sand and gravel operations. Their crushed stone is used for asphalt, concrete, and road building applications.