Change for the Better?
Written by John on July 8th, 2009
Change is defined by Webster’s dictionary as “to put or take in place of something else, substitute, to make different, alter”. When applied to the modern fire service and the fire service of just 25 years ago, it is readily apparent that changes have significantly altered apparatus, communications, staffing levels, operational capabilities, and numerous other factors. However, when the definition of change is applied to the fireground of 2009, there are four areas that have collectively combined to significantly modify or change current fireground operational considerations and firefighter safety as follows:
BUILDING CONSTRUCTION
A high percentage of modern buildings use a form of construction that has reduced the costs of materials and the time necessary to erect a structure. That form of construction is lightweight construction. The simple yet effective truss configuration has allowed multiple small members (i.e., 2X3 and 2X4-inch members) to replace larger structural members in spans that can exceed 100-feet. Unfortunately, as the size of a structural member is reduced, fireground time is also reduced. As an example, compare a modern 2X4-inch truss to an “older” bowstring truss. Although “a truss is a truss”, the modern truss utilizes 2X4′s that are connected by thin metal gusset plates. The older truss uses “rough cut” lumber of 2X10-inch or larger that is connected by steel plates and bolts. Are both of these structural configurations strong? You bet! However, will they react differently in a fire? Absolutely! Although the Uniform Building Code addresses strength, it does not address fireground time, which the modern truss has significantly reduced.
BUILDING MATERIALS
Building materials utilized on the interior of “yesterdays” residential and commercial structures were commonly comprised of conventional materials (i.e., paper, wool, wood, cotton, and other similar materials). When these materials ignited and burned, they yielded smoke and fire gases that often required temperatures of over 1000 degrees for ignition. With the advent of petro-chemical based materials (synthetics) commonly used in all modern buildings, the fire service is now faced with materials (i.e., TV’s, carpets, furniture, drapes, etc) that present a different hazard from two perspectives:
- Plastic based materials will ignite and burn 2-3 times hotter and faster than conventional materials.
- When plastic based materials are heated, they will emit a gas and/or smoke that will also ignite and burn 2-3 times hotter and faster than the gas and smoke emitted from conventional materials.
Therefore, the modern fireground environment is more capable of burning (or flashing over in shorter period of time) than the fireground environment of yesterday.
PROTECTIVE EQUIPMENT
Just a few years ago, typical protective equipment used by attack personnel consisted of boots, pants, coat, gloves, SCBA, and helmet. Although this combination had its advantages and disadvantages, it did allow personnel to use their ears and back of their hands to evaluate the level of heat in a fireground environment. This clothing combination also allowed the human body some degree of ventilation through the unprotected portions of the head. However, the typical modern firefighter is now protected by a Personal Alarm Device and hood. The hood has resulted in protective equipment that now totally encapsulates personnel. This has allowed personnel to withstand higher temperatures for a longer period of time, and the ability to quickly advance to the seat of a fire. However, these advantages can be easily offset by the ability of the same protective equipment to “mask the conditions” that attack personnel commonly used (past tense) to monitor the fireground environment. Additionally, when a firefighter is fully encapsulated, it is more difficult for the human body to ventilate itself in a hot-working environment.
Next week we continue with this installment.
