Demolishing a 27-story building presents huge challenges, but when you consider tearing down a structure in downtown Chicago it can create even more difficulties. Brandenburg Industrial Service Co. was hired as a subcontractor by Power/Jacobs, a construction manager, to do just that: remove the 85-plus-year-old Galter Carriage House on the downtown campus of Northwestern Memorial Hospital to make way for future development.
Brandenburg is no stranger to working in the congested downtown area, as the well-known demolition company was responsible for the destruction of the Chicago Sun-Times building in 2005 to make way for the 92-story Trump International Hotel & Tower.
According to Kelly Sullivan, director of media relations at Northwestern Memorial Hospital, the Galter Carriage House was built in 1926 as a five-story parking garage situated along E. Chicago Avenue in downtown Chicago. In 1960, additional floors were added to create a 27-story high-rise building that would eventually be used in part by Northwestern Memorial Hospital to house employees and patients. Lower levels of the Galter Carriage House were also used for retail and commercial purposes. Eli's Place For Steak, which had occupied space in the building since 1966, closed in the summer of 2005 in preparation for the demolition. It has been a popular spot for celebrities to visit on their way through the Windy City.
John O'Keefe, marketing manager at Brandenburg, says the $3.5-million project involves the asbestos abatement and demolition of the Galter Carriage House with more than 430,000 square feet of space spread out across 27 floors. Brandenburg crews started their work in September 2005, with an estimated finish date of June 2006.
"One of the keys (in demolition) is protection, especially in a downtown urban area," O'Keefe says. "For the Northwestern Memorial Hospital, in the area that is facing the street, we had the area set up with scaffolding so any debris that accidentally fell outside the building wouldn't hit a pedestrian or traffic. You need to set up all of your protective barrier structures before you begin your demolition."
There is always something you have to protect on these downtown urban projects," O'Keefe explains. "That is what makes them hard. You don't have a lot of room to work and it makes it difficult. It is much different from an industrial site where you typically have a large, open area around the building to work with."
Before any demolition was started on-site, Brandenburg crews were required to remove asbestos that was present in the structure. Crews found the hazardous material in floor tile, insulation surrounding pipes, and in some of the building's doors. O'Keefe says this material was sorted and removed separately from the general garbage and demolition debris.
After the environmental portion of the project was completed, crews made sure the electricity to the building was cut off or isolated, as well as the sewer and water service. Some electrical service was left in the building for lighting to do the demolition work and some water for fire prevention.
"These are isolated because one of the most dangerous things in demolition is cutting into utilities that are live; you want to stay away from that," O'Keefe explains.
With little room to work on-site, the equipment needed to carry out a project of this magnitude needs to be compact and versatile. Brandenburg has utilized a small fleet of Bobcat skid-steer loaders and attachments to assist with the demolition of the Galter Carriage House, according to O'Keefe. He says the company typically uses machines like Bobcat loaders, starting at the top of the structure as operators demolish the floors and eventually work their way down.
"On every demolition project, we have had at least one Bobcat loader," O'Keefe says. "The Bobcat loader is probably the most versatile machine we have."
But how do these compact loaders access the top of a 27-story downtown building? There are a couple of ways to transport these machines and attachments. O'Keefe says one way is to simply lift the machines to the top of the building with a crane.
"We lift them up to the top and we drop them off one-by-one," O'Keefe says. In some cases, there might be a freight elevator still working, or construction managers may build a freight elevator on the side of the building to carry the machines to the top."
According to O'Keefe, before the Bobcat loaders are used on any floor, a structural engineer uses a survey to determine if the floor structures are strong enough to hold the 8,400-pound machines. Once deemed workable, the Bobcat loaders travel across these floors and use hydraulic breaker attachments to tear apart the concrete, drywall and studs. All of the Brandenburg Bobcat loaders are configured with the optional high flow auxiliary hydraulics for enhanced attachment performance.
O'Keefe says the hydraulic breaker attachments are more precise than many of the other attachments available for their demolition applications.
"You can go around an area, break out the floor between the columns, and drop it," he explains, when using a Bobcat hydraulic breaker attachment and loader. "We want to open up the floor completely. The only thing remaining would be the columns supporting the structure. The columns are the last portion of the structure removed on each floor so that you can support your machines until you get down to the next floor."
Working from the top, inch by inch, these loaders break down the structure until they are ready to go to the next floor.
"Once the machines are up there, we typically use ramps to drive them from one floor down to the next," O'Keefe says. "We'll wreck the building down until we get to the little area we have left. You're basically going to demolish the building from the top down until you can reach it — down to a few floors — with the rest of your larger equipment, like excavators. Once the building can be reached with excavators, the skid-steer loaders are removed from the structure and utilized on the ground to assist with the clean-up and sorting debris."
All along the way, the Brandenburg S300 loaders, equipped with solid rubber tires, are loading and pushing the demolition debris with bucket attachments to side chutes on the sides of the building or elevator shafts where the material falls to a lower level. Then, skid-steer loaders located at the base of the structure sift through the debris with industrial grapple attachments to sort it, and then help wheel loaders carry some of the garbage to nearby dumpsters where it is taken to a landfill or a recycling center.
Most of the sorting is done by the Bobcat loaders and excavators, but in some situations it requires manual labor.
"Most of our machines are very precise on what they can grab," O'Keefe says. "Our large excavators, with a shear, can pick up a pop can. ... The machines have come a long way with hydraulics and rotation. They can do a lot of the sorting for us."
Brandenburg estimators calculated the demolition debris and garbage produced during this project. Estimates include 3,400 tons of garbage, 8,600 tons of brick, 1,600 tons of steel, and 32,000 tons of concrete will be taken from the concrete reinforced structure. The brick and concrete will be used as fill material or sent elsewhere and utilized by someone else to recycle, for uses such as road-base.
With little room on-site to process the steel, it was set aside, and eventually 1,600 tons were hauled off to a preparation site and cut to a prepared size for melting in steel mills.
Plans have yet to be announced for what will be located on the site. Officials say it will become a parking lot temporarily, but it may eventually be used for hospital expansion.
Located behind the demolition site is a new building — the Prentice Women's Hospital, which is scheduled to open in spring 2007. O'Keefe says Brandenburg was involved with the excavation of the site in preparation for a 937,000-square-foot hospital building. Northwestern Memorial Hospital records indicate the new women's hospital will consist of diagnostic and treatment space, patient care area and medical office spaces.