The Professor

BY GLENN P. CORBETT

Photo 1: Cornices, the decorative trim at the top of exterior walls of many 19th-century buildings, were typically made of stone, wood, sheet metal over wood, or just metal. This side view of a 21st-century descendent shows its synthetic polystyrene core and plywood backing. These new cornices still pose a collapse potential and can spread fire just like their ancestors.

Photo 2: This is an 1850s iron beam in an old mill. The inability of early 19th-century rolling mills to create flanges on the top and bottom necessitated the inclusion of this iron rod; the rod is used to deal with the tensile forces at the bottom of the beam.

Photo 3: The March 25, 1911, fire at the Triangle Shirtwaist Company in New York City is one of the most famous fires in American history. Fire spread quickly throughout the Asch Building’s 9th floor; a locked egress door and a collapsed fire escape were the primary reasons a total of 146 people died in the fire. Many people, primarily women, were forced to jump out windows. The fire led to many changes, including improvements in factory fire protection regulations and the strengthening of workers’ unions. This month marks the 100th anniversary of the fire.

Photo 4: This interior photo of a mill under renovation highlights a red flag for firefighters and inspectors. The presence of downward-pointing “drops” with sprinklers indicates that they will be positioned below a yet-to-be-installed ceiling. Concealed spaces—including dropped ceilings—are not permitted in buildings of heavy timber construction under the model building codes.

Photo 5: This is a wooden lintel over an opening into a storage area in a mill. Although the wood member is of heavy timber construction-compliant dimensions, moderate to heavy fire conditions for extended periods of time will cause it to fail, dropping the entire wall section above.

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 the editor of 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.