Firehouse Magazine, February 2006
The Challenges in Specialty Fires
By Jonathan Bastian
The majority of thermal imaging training focuses on TI use at structure fires. This is logical, as structure fires are the most common fire response. However, there are a number of fire departments that must plan for fires on board aircraft or ships. For example, in June of 2002, Anchorage, AK, firefighters had to extinguish several vehicles on fire four levels below the main deck in order to save a 790-foot vessel from disaster. Firefighters used a TI to navigate through a dangerous and maze-like vehicle hold, avoiding structural components as well as the vehicle tie-downs in order to find the fire. In January of 2003, Jacksonville, FL, firefighters fought a cargo container fire aboard a docked vessel, preventing the spread of the fire to hazardous materials. Here, firefighters used their TI to locate the fire and direct hose streams more effectively.
This month’s article will concentrate on the thermal imaging challenges that firefighters can face in aircraft and ship fires.
Aircraft Fires
While aircraft fires are relatively few and far between, airport rescue and firefighting (ARFF) services and municipal departments near airports face the potential for an aircraft fire every day. Proper training on response techniques, as well as the appropriate use of tools such as the thermal imager, can help ensure that if a response is needed, it is coordinated and effective.
Just as in structural firefighting, the TI can be used to assist in the size up of an aircraft incident, fire attack, search and rescue, and investigations. Despite this flexibility, there are a few challenges firefighters must remember as they train for TI use in an aircraft:
- Aircraft are constructed primarily of aluminum. Aluminum has a relatively low emissivity, meaning that it does not send its true temperature signature to the fire service TI. As a result, the metal can appear black or gray (indicating cold or cool temperatures) on the TI display, even when it may be extremely hot. This problem extends to any temperature measurement device on the TI. The temperature reading of unpainted aluminum could be off as much as 60% or 70% (see photo 1). Aluminum is also highly reflective of infrared radiation (heat), so firefighters need to be aware of how a scene may be altered by reflections of fire, victims, doors, etc.
- Aircraft have a number of obstacles, including seats, doors, carts and more. This can make a fast search difficult, because the TI cannot see through these obstacles. Firefighters engaged in a search need to remember the limitations of their TI, and ensure that they perform an appropriate search that includes thoroughly scanning all realistic areas in an appropriate amount of time.
Shipboard Fires
A shipboard fire can be a real challenge, especially for the municipal firefighter whose training and experience has primarily been in residential or commercial structures. The narrow passages, bulkhead doors, numerous deck levels and maze-like features of a vessel can be disorienting and disastrous for unprepared firefighters.
The advantages of using a TI in this environment are similar to the advantages of using the technology in an aircraft, possibly even enhanced due to how easily disorientation can occur in a vessel (see photo 2). While the threats of a ship fire may be different from those of an aircraft fire, many of the TI challenges are similar:
- Large vessels are constructed primarily of steel. Steel, like aluminum, will not show a fire service TI its true temperature. Temperature indicators will not have reliable measurements, although the error rate should be lower than it is for shiny aluminum. A bulkhead door hiding a fire may not display as white on the TI during the initial growth of the fire. However, once the steel heats up enough, the TI will help firefighters identify the location and extent of a fire, as well as the potential spread (see photo 3).
- The risk of disorientation is very high onboard a vessel. As a result, firefighters must be extremely cautious about remaining oriented with and without the TI. They cannot rely solely on the TI to lead them into and out of the environment. While this is true in a structure as well, the labyrinthine nature of the vessel’s decks and passages make orientation a life-critical issue on a ship. Land-based firefighters most likely will need rope lines to help them maintain a path of egress.
Conclusions
The advantages and uses of a TI at a structure fire are similar to the advantages and uses of a TI in aircraft or shipboard fires. However, due to the nature of the fires and the construction of aircraft and ships, the TI is more likely to encounter challenges not commonly encountered in the normal house fire. Proper training, preparation and practice will help ensure that the TI is an effective tool for firefighters, even in these difficult environments.
For additional information on these specialty fire challenges, please visit the Technology section of Firehouse.com. You can read the full accounts of the Anchorage and Jacksonville incidents online. Also remember that this column is accepting your true stories and your questions about thermal imaging. Send them to jonathan_bastian@bullard.com.
The exterior of an aircraft appears gray on the thermal image, even though there is a raging fire inside. The metal surface sends an artificially cold signal to the TI, potentially making proper image interpretation difficult. Notice the firefighter inside the doorway.
Firefighters entering a ship’s compartment can identify potential ventilation sources quickly. Here, the firefighter with the TI can see a port hole on the wall, indicating a way to extract smoke from the ship, or a place to gain a quick breath of fresh air.
Firefighters enter a compartment on a ship. The push of heat into the hallway indicates they have fire inside the compartment. The wall in the hallway is hotter on the left than on the right, helping firefighters identify the fire room.