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Learn about building construction features and hazards in Omaha that pose risks to firefighters. Discover dangerous structures and ways to stay safe in challenging situations.
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What’s In Your Area? Local Omaha Building Construction Features and Hazards to Firefighters
Local Building Construction,WHY? • Since it’s beginning, fifty-five (55) Omaha firefighters have been killed in the line of duty. Twenty-four (24) of them were due to some type of building collapse. That’s 44% of all Omaha firefighter LODD’s! • Building construction, collapse, and associated hazards are the #1 killer of Omaha Firefighters. • Frank Brannigan always said, “The building is your enemy, KNOW YOUR ENEMY”. • A building fire becomes a “structural fire”, once the fire moves from consuming only the contents to attacking the structure itself. • After a fire begins to attack the structural components of the building, it WILL, sooner or later, collapse! The deciding factor will be whether or not we are in them or on top of them when they do collapse.
What’s In Your Area? • The only way to keep the buildings we operate in from killing another Omaha firefighter is to, “KNOW, BEFORE YOU GO” • The following are a series of pictures of buildings taken around the Omaha area. • Along with the pictures, are a few basic hazards that accompany these buildings.
Cantilevered Canopy4230 UNMC Building (42nd St. between Leavenworth & Emile) These stressed steel cables will lose their strength once any part of the cable is heated to 800 deg. F. In addition, the cable supports could fail at the point they are connected to the building. The weakest area of any structural component is it’s connectors. Once the cable supports begin to fail, the canopy becomes an unsupported cantilever, in danger of collapsing onto firefighters operating under it. If the canopy falls, it could also pull the wall down with it.
Additional Roof Loads42nd & Leavenworth The original structural design of this building probably didn’t count on the roof supporting a billboard. The roof structure might not have a problem supporting the additional weight right now, but once it starts to become weakened by fire, the roof may collapse sooner than expected.
Hidden Bowstring Truss Roofs11th and Mason Street Bowstring “curve” Parapet walls From all sides at ground level, the parapet walls of this building conceal the type of roof it has . Only after stepping back a considerable distance and standing on a 4 ft. wall could I see the very top of the “curve” that characterizes the bowstring truss roof.
Hidden Bowstring Truss Roofs11th and Mason Street A view from inside reveals the characteristic bowstring truss with no ceiling. However, heavy interior smoke conditions could conceal the presence of the bowstring to initial arriving firefighters.
Bowstring Truss Roofs • Trusses are made to hold the roof up under normal conditions. Fire attacking any part of the truss is NOT a normal condition. • Once one part of the truss fails, the entire truss will fail quickly. • A truss (any truss, not just a bowstring) will be subject to failure after anywhere from 5-10 min. of exposure to fire. Once you find out that the truss is involved in fire, do not use the time limit, immediately evacuate all firefighters operating under and on top of a truss roof. • If there is a ceiling below the truss, heavy fire conditions can exist, and be attacking the truss, in this concealed space, and not be evident in the space below. • In 1988, five Hackensack, NJ firefighters were killed in a sudden bowstring truss roof collapse. • ALL TRUSSES ARE DANGEROUS, NOT JUST BOWSTRING TRUSSES!
Additional Hazards11th and Mason Street At this building, interior firefighters needing a quick emergency exit due to increasing fire conditions, sudden collapse of the truss roof, or any other emergency situation will be hampered by the fact that all windows are barred by metal security cages. RIT teams on scene can ensure that these windows are opened and accessible in case of a firefighter emergency.
Structural Stability Before the Fire10th Street- Between Pacific and Mason The building may not be in the best of shape even before the fire occurs, thus contributing to early collapse during a fire. The weight of firefighters operating on this balcony, in addition to the fire destroying the building, and the already unstable conditions of the wall could collapse the balcony and the firefighters on it, as well as collapsing portions of the brick veneer wall onto firefighters operating on the ground below. In addition, the balcony rail is not even attached to the building.
Structural Stability Before the Fire1009 William Street This wood frame balcony appears extremely unstable. Weakening by fire, along with the weight of firefighters could probably cause it to easily collapse.
Existing Structural Hazards 1009 William Street These exterior doors apparently once exited out onto balconies that no longer exist. I am not sure how they are secured from the inside or if they even appear as doors on the inside. However, if they are doors from the inside, it might be possible that a firefighter, at night and in zero visibility, could mistakenly try to pass through them or use them as an emergency exit during a MAYDAY situation. This would result in obviously dangerous consequences.
Haunted Houses716 N. 18th Street (Mystery Manor) During the Halloween season, many groups convert old buildings into “Haunted Houses” and charge admission to raise funds. During the rest of the year, these buildings sit closed and idle. The old Mystery Manor house is simply a bad day waiting to happen. Structural stability is probably not at it’s best to begin with. All of the windows and exterior doors are barred and locked, making an emergency exit for interior firefighters extremely difficult. These haunted houses are a different breed of building altogether. The interiors of these buildings have been altered in such a way that hallways, corridors, and rooms are a maze. They are made this way on purpose. It would not be hard for interior firefighters to get hopelessly lost. Unless it is during Halloween, and the building is occupied, an interior attack here would be a loser. Remember: Risk vs. Benefit
“Fake Mansard” Overhangs • In order to “dress up” the appearance of many commercial buildings, “Cornices, fake mansards, overhangs (sometimes called eyebrows), and other projections are being installed on many new buildings and added to old buildings to improve their appearance. They are usually of wood and sometimes poorly attached to the structure. They present a collapse hazard.”* • These “fake mansards” can be found on all types of buildings all over Omaha. • *Brannigan- Building Construction for the Fire Service, Ch. 4, Page 194
14545 Industrial Road These “fake mansards” are usually not a part of the actual roof assembly, rather they are simply attached, or hung, on the exterior wall of the building. If the points where they are attached to the building are weakened by fire, they can present a collapse hazard. This is an additional reason why the front of a building is one of the most dangerous places for firefighters to stand.
Doubletree Guest Suites 7270 Cedar Street These decorative attachments can be found on many different types of occupancies and at many different levels.
602 S. 72nd Street In addition to a collapse hazard, these attachments, which are usually hollow, also present a concealed space that fire can use to spread across the front and sides of the building. Fire which started in one business in a strip mall can spread inside the overhang across the front and re-enter the building in a previously uninvolved business. This building has three different overhangs. One original small overhang which can’t be seen here. A second overhang that was added on top of the first, and two new cornices that were recently built on top of the second overhang.
Phoenix Fire Dept. Motel Fire August 4th, 2006 The next few slides were taken at a motel fire where Phoenix firefighters were caught in the collapse of one of these “fake mansards”.
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