by Stefan Andreasson
I have worked at the (SRSA), Swedish Rescue Services Agency as a fire instructor for 12 years before it was closed down January 1, 2009. I now work with the Swedish Rescue Training Center (SRTC), a 310-acre training ground located 2 km from Skövde center. The practice field is structured as a miniature response area, featuring industrial and residential areas, countryside, and so on. The Center offers education and training in risk and security.
In my work as a fire instructor with Swede Survival Systems (SSS) and Draeger Safety Inc., I have worked with many firefighters from across the globe. SSS had a strong presence in Europe in the 1990s and was looking for ways to spread its type of training. In May 2004, Draeger Safety Inc. purchased SSS. SRTC has continued its working relationship with Draeger Safety exclusively. Our U.S. contact is John Hunter, based out of California; who has been instrumental in getting our training system up and running in the United States.
This cooperation with Draeger Safety has produced 17 courses with SRSA over the past several years. The content of the courses mainly has been to introduce how we practice firefighting techniques in the Phases 1 through 5 systems in Sweden, to give the students a little more knowledge of the props we have developed and how we use them. We differ a little bit in our techniques, training approaches, and implementation, but the students can take away the tips that help them most and put them to use back in their respective fire departments. To use the same training facility in slightly different ways gives us more opportunities. It has also been important for us to show the entire school to the students. At the school there is a hazardous materials practice field where we can offer training and practice in various scenarios, including tankers leaking ammonia. As far as I know, this is the only school in Europe where you can practice with real ammonia. Because of this, we have customers from many fire departments and industries.
Training with Instructors from Lausanne, Switzerland.
In the fall of 2009, I taught a course with eight fire instructors from Lausanne in Switzerland. The first day started out with a presentation about the school in a classroom setting, followed by a tour of the practice field and its training facilities. We also went to our equipment storage area to pick up the personal protective equipment the students would need during the week. We ended the day in the classroom teaching a course on fire behavior.
On Tuesday, participants were making their own labs with our so-called Kurt Olsson Boxes before it was time to display the Phase 1 system. The Kurt Olsson Box (photos 1 and 2) is a model of a room where we can watch the growth of fire. In the four room models, we can study both the growth of fire and fire spread to the other rooms. In both of these boxes, we can “play” with the openings to see the different behavior the fire takes with controlled ventilation. The boxes are made of particle board.
(1) Single-room Kurt Olsson box. Photos by author.
(2) Four-room Kurt Olsson box.
In the Phase 1 system, we look at the progress of a small fire we started until it reaches the flashover phase. During this demonstration, the instructor explains what happens throughout the course of the fire. The Phase 1 trainer is a great laboratory for understanding the fire behavior theory better. Students also had the opportunity to try their hand at an evolution in the Phase 1 system. At the end of the day, we presented our Phase 3 System, which shows the signs of an impending backdraft, as well as an actual backdraft.
The next day, it was time for the students to move from observation to actual extinguishing techniques. To apply the classroom knowledge of good extinguishing technology to a real scenario, it is imperative to understand fire behavior completely. How else can you understand how to properly use water for firefighting? Before undertaking practical exercises, I went through the theory in the classroom. I thoroughly discussed surface cooling, gas cooling, and water cooling as gaseous extinguishing agents. It is important to clarify the differences among these three methods. We practice all of them separately, but also together to practice as a whole. Firefighters have to understand how important it is to operate the nozzle appropriately to get the best result for an operation.
Surface cooling: Water is sprayed directly onto the burning fuel surfaces to stop the pyrolysing. You use it also for extinguishing and preventing pyrolysis..
Gas cooling: In enclosure fires that have reached flashover conditions, it is necessary to reduce the temperature and radiation before you continue cooling the fuel surface. This is done by employing gas cooling, in which the water evaporates directly into the hot flames and combustion gases. The major advantage of the water nozzle is the high hitting area of the water, which enables the water to affect a large gas mass. Effective gas cooling necessitates that the water droplets evaporate in the hot gases and flames. This is where the drop size comes into play.
Flaming hot gases are cooled, and they are removed through the tiny water droplets that the steam vaporizes and heats. The extinguishing takes place entirely in the gas phase, and the thermal load of the flame becomes so great that it goes out.
Water as a gaseous extinguishing agent: Using water as a gaseous extinguishing agent may be effective in cases where gas cooling is not appropriate. The method is sometimes called “indirect hydration” and is used only on fully developed fires and requires an enclosed space and the ability to vaporize water. This method works best in smaller spaces. The best effect is obtained if there are large, hot surfaces in the room, which are made evident by a hissing sound such as when water is poured on a heater.
It is advantageous if extinguishing can be done with spray from the outside through a small opening in what is otherwise a closed fire room. This helps prevent firefighters from being exposed to the hot steam. The water evaporates, and the steam fills the room with the fire. If the door to an adjacent room is open, the water vapor will spread, even though the fire has been knocked down.
We have concentrated our efforts on developing training facilities for gas cooling because we consider it important. We have two Phase 2 facilities for basic training.
(3) Phast one training facility, bottom, and Phase 2 training facility.
(4) Side view of Phase 2 training facility, top, and Phase 3 training facility, bottom.
(5) Phase 4 training facility, top, and Phase 5 training facility, bottom.
In a Phase 2 training facility that uses liquefied petroleum gas (LPG), students practiced using the direct attack method of extinguishment with gas cooling over and over again until they feel confident. We then switched to Phase 2 the indirect attack method with LPG. There are two fire rooms to be controlled by the students. Phase 2 indirect attack can also be combined with hardboard (Class A sheets of wood) sheets to block direct access to the fire. The students began the attack outside the door and then work their way through the system into the fire area. At the end of the day, we introduced the students to the Phase 4 system, which is built and most commonly used as an automotive repair garage. This system features fire scenarios that combine hardboard and LPG. Students must be much more innovative in advancing the nozzle and extinguishment. A gas-cooling extinguishment technique, in which flames and gases covered with tiny water droplets, is most effective in this system.
On the third day, we offered training in ventilation techniques. The Luleå house training building is perfect for this particular fire gas ventilation training. The house was built with two apartments spread over two floors, and is equipped with two stairwells and an attic. Both of the apartments can be uploaded and equipped with hardboard panels and firewall implementation, by place those boards at walls and ceilings in the burn room. We can also supplement the building with extra smoke in smoke barrels, if desired.
The first scenario went over ventilation techniques for the entire apartment on the ground floor. The exercise was conducted in three ways. First, the exercise was conducted with an outlet opening half the size of the incoming opening for ventilation purposes. The next scenario involved the same size opening for the incoming and outlet points. Both scenarios were carried out with the fan placed outside of the entrance door to the stairwell. These exercise showed that during positive-pressure ventilation (PPV), the exhaust opening should be at least as large as the incoming opening to achieve the best effect. If the opening is too small, the smoke and gases are more likely to move elsewhere within the structure. These are facts students have read about, but now they can see that it is true from first-hand experience. For the third test, the fan was placed inside the stairwell, which did not give the best results because the distance between the fan and the door to the apartment was too short
The last exercise was to perform PPV in the apartment on the second floor with heavy fire and thick smoke conditions. The fan was placed outside the entrance door to the staircase while exhaust air built up in the fire room (this step must be completed before the fan is placed in the doorway) to demonstrate the effects of ventilation. The fan was started and the door to the apartment was opened. It takes a lot of training and good communication for this exercise to be successful.
(6) Boatel, top, and Lulea house, bottom.
In the afternoon, it was the participants’ turn to create their own training scenarios, which we then executed in Boatel and House 1. The students wanted the training environment to be highly flammable, producing high heat and highly flammable gas. The participants’ wishes were granted, and participants were satisfied with the presentation of the exercises. After the respective exercise was conducted, we examined and reflected on the learning that took place. Sometimes, it takes briefings as long as the implementation of the exercise to thoroughly understand the scenario. This is also part of the exercise.
Stefan Andreasson is a fire instructor at the Swedish Rescue Training Center.
