BY THOMAS DONNELLY
A wide array of windows are used nationwide in renovations and in new construction at high-rise buildings. Emergencies at such sites may involve dangerous and difficult window removal operations. Many training venues and publications that address high-rise scaffolding emergencies say that you should use window removal only as last resort. However, on any given day, there may be many workers on scaffolding on the outside of these structures who may at some time need rescue. At an emergency for which firefighters must remove a window in a high-rise building, how can they do so safely? Below are outlined some basic steps and tools that help ensure safety when conditions dictate removing a window in a high-rise.
PREPARING THE GLASS
First, place suction cups on the glass to maintain control of the window when cutting the glass or the sealant around it. The window surface must be clean and somewhat dry for the cups to hold. Generally, place two suction cups in a vertical alignment, with the cup handles positioned horizontally, parallel to the window’s bottom ledge. Make sure the suction cups adhere firmly to the glass (photo 1).
 (1) Photos by author. |
Pressure-sensitive tape is standard issue for many fire departments across the United States with high-rise structures within their jurisdictions and is used in window removal. This translucent, tear-resistant tape is highly adhesive and comes in 18-inch-wide rolls that contain about 20 feet of tape, enough to cover about 30 square feet of window glass.
When applying the pressure-sensitive tape, make sure the glass surface is clean and dry. Two firefighters should work together in taping a window: One firefighter keeps the tape roll taut as it is unrolled and the other applies hand pressure to the entire surface so the tape attains maximum adhesion. If air bubbles develop, slash them with a pocket knife and smooth them down. Place tape over and around the suction cups; use a pocketknife to cut away tape to expose the suction cup handles after you apply the sheet. Apply the tape from the top to the bottom of the window in side-by-side strips, overlapping each strip until you have covered the whole window (photos 2, 3).
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At the bottom of the window, use a knife to cut the sheet of tape just applied from the tape roll. Remember that the tape is extremely sticky. Before cutting, apply duct tape to the edge of the roll so it is easy to start the tape when you apply the next sheet to the top of the glass (photo 4). When cutting the tape, maintain a constant tension; do not allow the cut portion on the roll to curl up and stick to itself or to the roll. Repeat the process until you have covered the entire window. Removing a large-square-footage window is very difficult and would require multiple suction cups and several rolls of tape.
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Pressure-sensitive tape generally has only a one-year shelf life, after which it will begin to lose its adhesive quality and may come loose once you start a window removal operation. This is particularly dangerous if you are going to cut the window. Make sure your tape is not more than a year old.
REMOVING THE WINDOW
Only remove glass in a high-rise building on orders from the incident commander. Remove the window either by cutting it entirely from its adhesive sealant or by cutting a section of the glass.
Safety is paramount during a window removal operation; follow basic safety procedures. Before cutting, designate one firefighter to maintain control of the window by holding onto the suction cups while a second firefighter performs the cutting operation. Both members should wear appropriate eye protection and a Class 3 high-angle harness atttached with a static kermantle safety line belayed to a substantial anchor (photo 5).
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Introduced to fire departments nationwide in the mid-1990s, the lightweight electric rotary cutter is the tool to use to cut the adhesive sealant along the window frame so you can remove the window intact (photo 6). Once you have cut the adhesive sealant, pull the window clear of the frame into the building. This tool is especially maneuverable and easy to handle; can go into small areas, corners, and wedges; and has a guard attached to it to maintain a straight cut.
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Remember, however, in this operation, you may have to remove window framing to access the window sealant, which may take more time. Also, this rotary cutter necessitates a nearby electric source or a portable electric generator.
The newest tool for glass-cutting operations is a compact, lightweight, 18-volt, battery-powered, glass-cutting saw that has a tilting base for cutting up to a 45° angle (photos 7, 8). This tool has an adjustable cutting depth and a blade diameter of 33⁄8 inches. This saw uses a blade designed specifically for wet-cutting glass. The blade has a smooth, continuous rim that cuts evenly without chipping or producing glass fragments. As with many of the other 18-volt battery-powered tools, keep two fresh batteries available; depending on the square footage you need to cut, you may need the second battery.
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When using the wet-cutting blade, keep the cutting surface cool, and constantly lubricate it with water; cutting glass generates a fair amount of heat. Keep the cutting surface cool, but do not saturate it; a small spray bottle of water usually suffices to facilitate the cutting.
CUTTING THE GLASS
When cutting the window glass itself, make the cuts in the following sequence. First, make a horizontal cut at the top of the window and a second horizontal cut at the bottom of the window. Then, make two vertical cuts to complete a square. This will allow you to pull out the window in a horizontal or side motion and prevent the glass from binding on itself. It also allows for greater control of the window with the suction cups (photo 9).
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If the window has two separate panes, one on the inside and one on the outside, a common feature in many high-rises today, remove each pane separately. The saw operator must cut only to the depth of the inner pane and not sink the blade all the way through the window, since he does not have control of the outer pane. Once you cut the glass, you can remove the entire window safely in one piece with a minimum of fragments (photo 10). Cutting the glass is quicker than just cutting the adhesive seal, since it does not require removing the window framing and trim to expose the sealant, which saves valuable time in a potentially serious operation.
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The glass-cutting saw is a welcome addition for high-rise glass removal operations. Although cutting glass in a high-rise operation is not an everyday operation, it is one that we should be prepared for, given the number of high-rise buildings that may have workers operating on the outside of them every day. Whether the incident involves a scaffolding collapse or an injured worker on a scaffold, the rescue unit is capable of safely and efficiently conducting this operation, with a definite margin of safety.
TOM DONNELLY is a 24-year fire service veteran and a lieutenant assigned to Fire Department of New York (FDNY) Rescue Company 1. A member of FEMA USAR NY-TF-1, he has served as a firefighter with Rescue Company 2 and Ladder 176. Donnelly is an instructor at the FDNY Technical Rescue School and has been an instructor with the Suffolk County Fire Academy for 16 years. He has a bachelor’s degree from Saint Joseph’s College in Brooklyn, New York.
