The Professor

BY GLENN P. CORBETT

Photo 1: Some firefighters call the push bar across the center of the door “panic hardware.” It is actually called “fire exit hardware,” since it is used on a rated fire door in this photo. Panic hardware can only be used on nonfire-rated doors. Found in places of public assembly, both types of hardware are very similar in appearance—the only difference typically is the extra vertical rods to latch the fire door at the top and bottom in addition to the latch on the left side of the door frame. Fire exit hardware is also not permitted to be “dogged,” where the push bar is fixed in the “depressed” mode and is not latched.


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Photo 2: This wood-frame structure carries not only its own weight and everything inside but also these two massive billboards. What would be the result of a cockloft fire burning below? What is the combined dead load of these signs?


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Photo 3: The masonry “face” of the American Museum of Natural History in New York City is under repair. While protecting passersby from the resulting dust cloud, the “cloak” hinders access to the building’s windows, making ventilation and potential rescues difficult. The sheeting also hides an enormous amount of scaffolding used for the repair work. Is the sheeting material combustible?


Photo 4:Multistory open parking garages are typically equipped with Class III standpipes (21⁄2-inch hose valve with 11⁄2-inch hose station, as seen here) that are supplied with water by a dry pipe alarm valve, or a completely dry Class I standpipe (21⁄2-inch hose valves only), to which you supply all of the water through a fire department connection. Be aware that getting the air out of the system, particularly the completely dry Class I system, will take time. Vandalism and lack of maintenance on both types of systems are common.


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Photo 5: The 100th anniversary of the Rhoads Opera House fire, which occurred on January 13, 1908, and killed 171 people, was recently commemorated in the small town of Boyertown, Pennsylvania. The fire is believed to have started when a magic lantern stereopticon projector (the forerunner of the old slide projector), which used a hydrogen-oxygen mix to create a bright projection light, leaked flammable hydrogen gas into the room, which subsequently ignited. This month’s “History on Fire” photo reminds of the special construction required for today’s motion picture projection rooms. Rooms must be separated from the theater and be specially ventilated, including individual ventilation for each projector.


Photo 6: Both of these buildings appear to be of ordinary construction. Although that is true for the building on the right, the building on the left is actually a wood balloon-frame building. It was a derelict burnt-out structure that has been completely rehabilitated, including the use of a fake brick veneer face. It still has all of the problems of a balloon frame but now presents a more difficult situation for firefighters who might have to access the stud channels from the exterior to stop upward fire spread.


GLENN P. CORBETT, PE, is an associate professor of fire science at John Jay College of Criminal Justice in New York City, is a technical editor for Fire Engineering, and was an assistant chief of the Waldwick (NJ) Fire Department. He previously held the position of administrator of engineering services with the San Antonio (TX) Fire Department. Corbett has a master of engineering degree in fire protection engineering from Worcester Polytechnic Institute in Massachusetts and is pursuing a Ph.D. in public administration from Rutgers University. He authored two chapters on fire prevention/protection in The Fire Chief`s Handbook, Fifth Edition (Fire Engineering Books, 1995) and is the coauthor of the late Francis L. Brannigan’s Building Construction for the Fire Service, 4th Edition. He is editor of the upcoming Fire Engineering book Firefighter I and II Handbook. Corbett is an FDIC Executive Advisory Board member. He has been in the fire service since 1978.

The Professor

BY GLENN P. CORBETT

Photo 1: Commercial buildings usually come to mind when we think of steel as a structural member. Steel frames have become a staple in the single-family home arena as well. This “Fred Flintstone” home presents an unusual situation for firefighters.


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Photo 2: The 1835 “Great Fire of New York” was Manhattan’s biggest, consuming nearly 700 buildings in the Wall Street area. As this month’s “History on Fire,” this conflagration reminds us of firefighting efforts of the 19th and early 20th centuries. Explosives were used in most conflagrations (including this one) to create fire breaks, very often actually increasing the spread of the fire. Ironically, this issue is still with us today: Most of today’s fire insurance policies specifically exclude payouts to property owners who have had their home destroyed or damaged as the result of an “order of a public authority.”


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Photo 3: Water from sprinkler systems protecting high-rack storage areas must be capable of penetrating through to the burning materials in the lower levels of the rack, hence the need for open metal mesh shelves as seen here. If wood panels (plywood, etc.) or closely spaced boards are used as shelves under the stored commodity—a storage arrangement known as “solid shelving”—“in-rack” sprinklers are then required at each level of the rack under each shelf.


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Photo 4: If you are a pump operator and are in search of a water supply in an old industrial complex, stay away from this type of hydrant! It is a “yard hydrant,” intended to supply directly attached handlines exclusively with its two 2 1/2-inch outlets.


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Photo 5: This is a decorative cover below a roof-mounted smoke and heat vent in a hotel atrium. Smoke approaching this fusible-link-activated vent will be blocked by this cover, negating its effectiveness. Firefighters on the roof should be very careful when approaching these vents, as they are spring-loaded (to throw off a substantial snow load) and will cause severe injury if a body part comes in contact with the rapidly opening panels.


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Photo 6: Slate roofs are often thought to be predominantly in the north, but this one is in the heart of Texas in downtown Houston. When loosened by the collapse of the roof or when struck by an aerial stream, the slate tiles can become “flying razors” and cause severe injuries to firefighters below.


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GLENN P. CORBETT, PE, is an associate professor of fire science at John Jay College of Criminal Justice in New York City, is a technical editor for Fire Engineering, and was an assistant chief of the Waldwick (NJ) Fire Department. He previously held the position of administrator of engineering services with the San Antonio (TX) Fire Department. Corbett has a master of engineering degree in fire protection engineering from Worcester Polytechnic Institute in Massachusetts and is pursuing a Ph.D. in public administration from Rutgers University. He authored two chapters on fire prevention/protection in The Fire Chief`s Handbook, Fifth Edition (Fire Engineering Books, 1995) and is the coauthor of the late Francis L. Brannigan’s Building Construction for the Fire Service, 4th Edition. He is editor of the upcoming book Fire Engineering’s Handbook for Firefighter I and II. Corbett is an FDIC Executive Advisory Board member. He has been in the fire service since 1978.