Brandenburg Industrial Service Company was recently contacted to take on a new project, the demolition of a large plant that had been home to 4,000 employees of Armstrong World Industries. A crew of 70 Brandenburg workers was dispatched to the 2.3-million-square-foot facility in Lancaster, Pa., formerly the world's largest floor-tile factory. The site is comprised of approximately 25 buildings that had been constructed side by side at different times during the plant's lifetime, with the oldest structures having origins dating back 100 years.
While the history and character of the complex — including a brief wartime re-allocation of resources to build ammunition cartridge cases and rocket bodies — had grown over the course of a century, the time frame for bringing it all down was far more compressed. Brandenburg hit the job site in September 2006 with a deadline of October 2007 looming just 13 months away.
"The aspects of the job itself are pretty straightforward for us — asbestos abatement, contaminated soil remediation and, of course, demolition," said Moore. "But the magnitude of the project is significant. In terms of the size and amount of material to be demolished on this job, it's among the top 10 percent we've encountered."
With time being a critical factor, Brandenburg responded accordingly by supplying a full complement of equipment to the site, including several excavators equipped with shears, processors, magnets, and grapple attachments. While the attachments were very effective for several breaking and dismantling tasks on the job, some areas of heavy concrete were either inaccessible or too large to be handled by shears and processors. Not only were these concrete sections present, but they also existed in substantial quantity.
"We estimate that the project will generate 200,000 cubic yards of concrete," said Moore. "The plan is to crush the concrete on-site using a large portable crusher and recycle it either as base material or as construction material for basements in the new facilities. But before we can get to that point, obviously the concrete needs to be broken up first. That's where our hydraulic breakers come in."
To tackle the concrete breaking tasks in smaller, tighter areas of the project, Brandenburg brought along four Bobcat skid-steer loaders, each equipped with an SB 450 hydraulic breaker attachment from Atlas Copco Construction Tools LLC. The SB 450 has a service weight of approximately 900 pounds and provides a maximum impact rate of 780 blows per minute. Each breaker attachment has been in Brandenburg's fleet for four years.
Said Moore: "When it comes to concrete demolition, impact energy is definitely the name of the game, but these breakers provide additional advantages. The SB 450 requires less oil from the carrier than other models we've used, the hydraulic return line isn't sensitive to back pressure, and it doesn't require any special plumbing."
Brandenburg's equipment at the job site also included Liebherr excavators carrying two Atlas Copco HB 4200 hydraulic breaker attachments, which like the SB 450 units, had been purchased four years ago. Offering a maximum impact rate of 540 blows per minute and delivering approximately 6,000 foot-pounds of impact energy, the HB 4200 has been an effective solution for breaking up the large concrete slabs, foundations and floors at the plant.
"We've been going from building to building with the larger breakers," said Moore. "The thicknesses of floors and walls in the various structures vary quite a bit, so it's difficult to precisely calculate just how productive these breakers have been. Suffice it to say, we've always been very pleased with their breaking performance."
The HB 4200 utilizes a standard VibroSilenced damping system that greatly reduces the breaker's noise level. The box design of the breaker itself acts as a muffler around the percussion mechanism. The system also includes an arrangement of elastic damping elements that plug maintenance access holes in the box. These plugs further isolate and contain the sound generated when the piston strikes the working tool. Furthermore, polyurethane wear components are used to limit the actual vibrations, which not only reduces noise, but also offers additional internal protection for the breaker.
This attribute has come in handy in Lancaster, with the manufacturing plant located in the middle of a residential neighborhood. "Noise is definitely a concern," said Moore. "It's impossible to eliminate the noise of the breaker's tool steel hitting material, so it's very helpful if the decibel level from the breaker itself can be kept to a minimum."
The durability of the breakers is further enhanced due to DustProtector II, an optional system that Brandenburg purchased for each of its HB 4200 breakers. The dust guard system uses an additional seal to prevent debris from entering the breaker through the lower bushing area. The system also helps keep lubricant in the lower bushing for longer periods of time, thus lessening the chances of wear or other potential damage.
In addition to the approximately 400,000 tons of concrete being demolished and recycled on the job, Brandenburg will be removing asphalt parking lots and roadways, with the materials being sold to local asphalt plants. The company has its own semi-trailers and railroad cars that are expediting the removal of scrap metal from the site. Brandenburg also expects to recycle more than 2 million bricks from various buildings on the project.
Once the old plant has been removed and the site has been cleared, construction will begin on the location's new facilities — an office complex for Lancaster General Hospital and athletic fields for nearby Franklin & Marshall College.