Under control: excavators replace wrecking balls as controlled demolition becomes more popular on job sites.
Loosely defined, controlled demolition is taking down a building in a safe manner that allows the debris generated to be under the control of the demolition contractor as much as possible and not bouncing around the site. And perhaps the best way to do that is to use modern demolition equipment--a high-powered excavator with a specialized attachment.
IN WITH THE NEW
In the days when the wrecking ball and crane ruled the demolition site, other machines took a backseat. "It used to be that excavators and loaders were only used to sort and load out materials," says William Gumbiner of Demolition Industry Consultants, Noblesville, Ind. "Now, with all the attachments, excavators are on the front line of the demolition job."
These machines are taking the place of the long-time industry stalwart, the crane equipped with a wrecking ball. Excavators fitted with various attachments excel at taking a structure down piece by piece. Discussions with some demolition contractors across the country reveal that cranes are still out there and still being used, but not as much as they used to be for a variety of reasons.
First and foremost seems to be a dearth of skilled operators. There are few replacements for the large number of older operators retiring. "Everyone used to have a lot of crane operators," says Gumbiner. "They are just not around any more."
A good operator is important for a couple of reasons. The first is safety.
Berger Jostad of Viking Demolition, Glendale, Calif., is an industry veteran who says he "never did like that thing wobbling on the end of a string. It didn't seem to matter how experienced the operator is, he couldn't always control the ball."
Because of safety concerns, many local governments seem to be supportive of the trend, some contractors say. Jostad says he sees very few buildings being balled down anymore, not the least of which is because "cities won't let you swing the ball any more, it is a violation of permit." When it is used, it is usually just to drop it to break up concrete floors.
Drew Lammers of King Wrecking in Cincinnati uses an example of a 15-story building being demolished while flanked by 10-story buildings to show the importance of the control a demolition contractor must have in most situations. And in tightly-packed metropolitan settings, control becomes all the more important.
"It takes much more experience to control the wrecking using a crane and ball." Indeed, Lammers is of the opinion that the ball and crane are being phased out, and may even be banned altogether one day.
Another reason the wrecking ball is not being used as much may be simple economics. Lammers says the cheapest way to demolish a smaller building is with an excavator with an attachment. Gumbiner says that in the past cranes were needed to get taller buildings down. "You can still do it that way," he says, "if you can find the operators."
But a structure's size doesn't neccessarily have to be a limiting factor when it comes to choosing between controlled demolition and its traditional counterpart. With today's high-reach excavator equipment, a more than 90-foot reach is possible. Even a regular excavator, working on a couple of stories' worth of material piled up, has a high-reach capability. And while commercial work can often be taller than that, almost all industrial work is shorter than that, making the excavators an ideal choice.
Economics also favor modern excavator equipment because of labor savings. Gumbiner recalls the days when some jobs would require nearly 80 burners to complement the crane and wrecking ball just to get the building down. "Now you might only see 10 on the job, so the excavator makes it safer," he says.
In fact, many demolition contractors say that the projects where the ball is appropriate are dwindling, and that is why there are fewer cranes and operators are difficult to find. However, Dennis Wager of Impact Demolition, Vancouver, B.C., Canada, says that having cranes and operators make sense "if you can keep them busy."
Some speculate that rising insurance costs are another prohibitive factor when it comes to the old fashioned crane and wrecking ball approach to demolition. Robert Elster Jr. of Apollo General Insurance Agency, Sonoma, Calif., says that a lot of insurers won't insure the wrecking ball jobs anymore. "It is a perception from the old days," he says, "when everybody seemed to have a claim. But if we have a good contractor with an experienced operator, we don't have a problem getting him insured."
But Elster wonders why someone would want to use the crane "with all that great equipment we have out there to do the job." This new equipment, especially the excavators and their attachments, has helped reduce the number of claims and improve the demolition industry's safety record.
Even as excavators fixed with an arsenal of attachments become more prominent on demolition jobsites, some say that more traditional demo practices will never completely go out of style. Gumbiner says he thinks that there always will be a place for the wrecking ball and crane in the marketplace. "Cranes will never go away," he says. "You still have buildings that are heavily concrete, very tall and can't be shot. For those, the best option could be the wrecking ball."
RELATED ARTICLE: Demo association outlines plans.
Saying it was "time for demolition contractors to take their rightful place in the construction industry," Michael Taylor, executive director of the National Demolition Association, outlined a plan of action the association would take in coming years. He made his remarks at the association's recent Annual Convention in Las Vegas.
Chief among those moves is to expand the association's membership to include all companies involved in the demolition process. He specifically named architects, general contractors, and CSD recyclers as targets.
Architects are important, Taylor said, because of their role in the design process of buildings. General contractors do about 20 percent of all demolition work now, especially interior renovation, and "we have to show them we can do it better and faster," he says. Finally, C&D recyclers handle the material the demolition industry generates.
Taylor also described how the association's recent name and logo changes fit into this plan. Dropping the word "contractor" from the name, while painful for some members, was necessary because the name was exclusionary. "To expand in the 21st century, we had to lose that word," he says. The new logo, with its swoosh design to denote progress, also has the association's tagline, which describes it all: "Preserving the past, preparing the future."
He also talked about the opportunities the industry faces, such as brownfields work and becoming certified to be first and second responders to natural and man-made disasters. Finally, Taylor outlined an aggressive marketing campaign to construction magazines to promote the industry's services.
Other action taken by the board was a discussion on being first responders to disaster sites. Not every demolition contractor is qualified to handle this usually dangerous and sometimes controversial duty, and one possible goal is to have certified disaster site workers.
Another discussion centered on the demolition education program being developed at Purdue University in concert with the association and creating a textbook for demolition.
RELATED ARTICLE: Controlled demo at work in the windy city.
When Donald Trump comes to town, people notice. And when he came to Chicago to build one of the biggest buildings in the city along the Chicago River, people really noticed, including Mayor Richard Daley.
On top of that, Trump wanted the building on the site of a venerable local landmark, the Chicago Sun-Times Building, which meant even more scrutiny. It didn't help that in the middle of the wrecking, "The Donald" and "Da Mayor" got in a public spat over the design and height of the new building.
That was the microscope Brandenburg Industrial Service Co. was working under when it began demolishing the long-time headquarters of one of Chicago's two daily newspapers.
It could not be a more urban job: On one side was the Wrigley Building, on another the IBM Building, on the third a luxury high-rise mostly residential building. The Chicago River made up the fourth side. And the 1950s-era Sun-Times Building was bigger than it looked, according to William Moore of Brandenburg. Its 55,000 square feet and nine stories were L-shaped, which meant some of the structure wasn't easily seen from the street.
It was also sturdier than most believed, Moore adds. While most people thought it to be concrete framed, it turned out that concrete only sheathed a steel frame. In addition, as the building is right on the river, there was concern about debris falling into the water. Brandenburg tied up two barges right next to the building to catch any falling debris, purely as a safety measure. No material was loaded on the barges.
The barges allowed for no scaffolding to be used, a much more expensive alternative. At the start, skid-steer loaders with hammer attachments were lowered onto the building roof to help gut the building and get the concrete off the steel. All the material was sent down a chute in the middle of the building for load out.
About 62,850 tons of material was generated by the project, reports Moore. About 2,800 tons was waste, "about the only thing that couldn't be recycled," he says. Of the rest, 55,000 tons of it was concrete, 4,900 tons was steel and another 150 tons was nonferrous metals. All of it was recycled, including the concrete.
"Why wouldn't we recycle it?" says Moore. "We would have to pay $400 to $500 per load to dump it at a transfer station, as opposed to $10 to $50 per load at the recycling plants. And they are all closer than the transfer stations."
Brandenburg's part of the job was finished by the start of April 2005, but even before that, end caisson drillers were working on one side of the property while the demolition company finished on the other.
The author is associate publisher of C&DR and executive director of the Construction Materials Recycling Association. He can be reached at firstname.lastname@example.org.
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|Title Annotation:||Controlled Demo|
|Publication:||Construction & Demolition Recycling|
|Date:||May 1, 2005|
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