Dunn Deal

As Oldcastle Inc. turned 30, the latest in a long string of investments validating a successful business model honed in Ireland was rising on a Dunn,

Don Marsh

As Oldcastle Inc. turned 30, the latest in a long string of investments validating a successful business model honed in Ireland was rising on a Dunn, N.C., greenfield.

The centerpiece of Oldcastle Architectural’s current capital program is a twin-machine block & paver plant with prodigious raw material transfer and storage. Soon to become a workhorse of the Adams Products Co., the Dunn plant is built on a 42-acre site in Edgerton Industrial Park, just over a mile from an interchange with (Maine-to-Florida) Interstate 95. The facility embodies the strategic location and output muscle Oldcastle Architectural has instilled in the past decade’s greenfield investments. It also extends best practices-applied to greenfield and existing plant overhauls-with new safety provisions and energy efficiency.

We have five goals in plant design and operation: Safety and quality, one and two, followed by productivity, housekeeping and preventive maintenance, says Oldcastle Architectural CEO Keith Haas. At Adams Products-Dunn, we started with the safeguards and operating procedures that have brought our rate of lost-time category accidents to one of the lowest in the manufactured concrete industry.

This is our first plant to meet ANSI Category 3 safety protocol for electrical equipment, he adds. There is double redundancy in automatic shutdown mechanisms that must be activated to access all gated production, curing and product handling areas.

Redundancy is achieved with trapped key technology, geared for routine access but not as a lockout/tagout substitute. Keys unlocking bolts to gated areas are trapped and released in a sequence determined by isolating power and control; a gate key, for example, can only be used after the local power source is disabled. Breaches spur full production line shutdown.

Investment in the trapped key technology is an acknowledgement of plant automation: The ability of a production line like Adams Products-Dunn to run with a very small staff lessens the safeguard that would typically be realized with clusters of employees, who in product machinery and handling areas could quickly respond to a coworker whose safety is compromised.

ENERGY CRUNCHING

Oldcastle Architectural will target ANSI Category 3 protocol for future greenfield plants, and apply it to the gradual upgrade of existing block & paver lines. Another standard at Adams Products that will carry to future plant design is the use of premium efficient frequency drive motors in lieu of AC induction models. Conveyors and machinery at Dunn run Super-E motors, which Baldor Electric has designed to comply with efficiency mandates the Energy Independence and Security Act of 2007 (EISA) calls for by December 2010.

The design phases of Adams Products-Dunn coincided with Oldcastle Architectural’s launch of the Energy Management Program. We have been studying energy consumption, electricity rates and billing across the company for more than two years, says Oldcastle APG South President Tim Ortman, whose region encompasses the Carolinas, Georgia, Alabama, Louisiana, Tennessee and Florida. All plants have been surveyed to identify measures to lessen peak loads and total amount of power required.

The Energy Management Program has seen a representative from the Oldcastle Architectural corporate office in Atlanta meet with local utility officials to identify peak load reduction and secure appropriate electricity rate plans. Corporate staff has worked with designated Utility Specialists at each plant to monitor consumption and identify ongoing power savings opportunities. Energy efficiency measures, including those tied to EISA-compliant motor specs for Adams Products and future capital projects, account for about 20 percent of $2.5 million in savings Oldcastle Architectural reports through Energy Management.

The program has so far been used for internal purposes. Nevertheless, it stands to bolster the environmental proposition Adams Products has made in the era of Leadership in Energy & Environmental Design rating points for building projects. As LEED guidelines evolve, building design professionals will look closer at the embodied energy of a finished product-along with recycled content. For now, Adams Products has developed The Greenline Recycling Program and Greenline 31 Concrete Masonry Units, for LEED-centered projects.

Under normal economic conditions, Adams Products has no shortage of customers and prospects assessing LEED rating points or life cycle cost, a concept that has always favored masonry methods. Dunn is strategic to the Raleigh-Durham market and Research Triangle Park, which offer a strong mix of university and commercial building prospects, and military work-fueled Fayetteville, home to Ft. Bragg. Universities have been at the forefront of adopting various levels of U.S. Green Building Council LEED certification.

On the residential building side, the Carolinas offer a full-line producer like Oldcastle Architectural-with clay brick, innovative concrete veneers and a stable of structural masonry products -a market whose per capita use of brick and block is among the country’s highest.

With a full-line of traditional masonry products complimented by new innovative concrete veneers like the Suretouch system, Adams is well-positioned to give our customers a competitive advantage in the marketplace, says Adams Products President Colin Clampett.

The Dunn plant consolidates building and hardscape unit capacity from Adams Products’ Wilson and Fayetteville, N.C., facilities, which are running equipment that is mostly a decade or older. With the benefit of skilled labor from the two decommissioned plants, the Dunn startup went extremely well and both machines are now ramping up to full capacity, notes Clampett. Adams Products spans nine block & paver plants in the Carolinas and Tennessee, with sales and distribution in 15 centers or yards in those states, plus Virginia, he adds.

MATERIAL MAGNITUDE

Impressive raw material transfer and storage at Dunn begin with a 1,500-ft. arcing rail spur to receive lightweight aggregate from an Alabama plant of Big River Industries, a sister Oldcastle Architectural business. The spur traverses a main grizzly and can stage up to 10 cars for storage. An adjacent drive-over grizzly receives sand from a local mine. By way of a radial stacker/incline conveyor, the rail and dump hoppers feed two shuttle conveyors serving two rows of eight silo-shaped bins, totaling nearly 2,200 tons of capacity. The radial stacker allows for additional material stockpiling.

Aggregate batching consists of four weigh belts mounted below the bins, which through incline conveyors feed material holding hoppers serving twin Haarup 3750 mixers, mounted on a common platform. The bin and conveyor arrangement is designed to allow both mixers to be served by any of the 16 aggregate vessels. Each mixer receives cement from weigh batchers, which are fed by screw conveyors serving one 110-ton and two 190-ton silos. Both mixers have a central dust-collection system equipped with auto-recycling to return material to one silo. Water is metered into the mixers.

One mixer serves a Besser Superpac machine, the other a Tiger TG4S. Each has four discharge gates, three for material blending and feeding a scale-mounted mix hopper with variable-speed driven feed conveyor, which in turn charges the machine feed conveyor belt.

The arrangement allows up to three-color blending in any combination or design to either machine line. A fourth discharge gate on each mixer is used for clean out, or for bad-batch disposal without disrupting the color blending cycle.