Burning dollhouses - A cost effective way to demonstrate Fire Behavior
Creating miniature fire compartments, so called "dollhouses", is a cost effective and easy way to demonstrate Fire Behavior. Depending on your local regulations, a dollhouse burn in good wind conditions or a space with forced ventilation won't necessarily require the use of full PPA but can be done safely with simple filter masks.
Many firefighters of course feel that full scale live house burns is the best way to practice fire training and to demonstrate various types of fire behavior related phenomenons like Flashovers, Backdrafts, Ventilation Controlled Fires, Fuel Controlled Fires and so on.
However, local environmental regulations can make full scale houses difficult to acquire and prepare, and if only practiced once in a while, many firefighters might miss the opportunity to practice. Also, municipal safety officers are often cautious in their attitudes towards full scale burns, which they mean can expose firefighters to unnecessary risks.
It can also be expensive and time consuming if you need to remove all the toxic materials like electrical wiring, fuel tanks, vinyl sidings and insulation from the structure before you burn it. If you want to practice the same tactics over an over again, you often need several of the same types of structures, since a burning full scale house is difficult to control, and often only lasts for one or two training sessions before it will have to be destroyed.
Container Training - meaning burning more or less realistic fire scenarios inside a regular metal sea can - is another form of relatively cost effective simulated fire compartment training preferred by many training officers, and allows firefighters to practice nozzle techniques, fire gas cooling and other forms of tactical firefighting in a relatively safe environment.
All this being said, container training is still relatively expensive if all your are trying to accomplish is to train a group of students or novice firefighters, or if you simply would like to demonstrate and practice some repeated and predictable points in Fire Behavior.
The sea can will eventually wear out and get destroyed, and you will need many packs of air both for the instructor, the students, and perhaps also for the bystanders, if winds are unfavourable. Often, the pain on the metal containers create very toxic smoke and the inside of the container will be very toxic also after the burn.
Dollhouses, on the other hand, can be made with with very clean wooden materials, can cost as little as €20 or less to make, and if correctly used, can be re-used as many as 2-5 times depending on how far you allow the fire to develop.
Dollhouses can be made as simply or as complex as you´d like - from a simple "box", simulating a single compartment house or a room fire, to complex structures with several floors, attics, crawl spaces and complex ventilation openings.
In this simple video above, international fire instructor Shan Raffel demonstrates the most simple form of dollhouse. With the use of a removable door and a "fog nozzle" consisting of a flower spraying bottle, he brings the fire compartment from the initial stages of fire to the stage where the fire is "ventilation controlled", meaning that the compartment is close to flashing over but has run out of available oxygen inside the fire compartment.
Opening and closing the "door" to the dollhouse creates a very realistic simulation of a Backdraft / Rollover (modern American term) or as the Swedish pioneers of Fire Behavior called it, a "Flashover". (The term Flashover now has a different meaning than it did back then.)
This video is shot by Terri Casella and Björn Ulfsson (BT Video Productions Ltd) at the National Research Council, Ottawa, Canada during a training session with Ottawa Fire Service in October 2015.
Australian instructor Shan Raffel is a pioneer of Fire Behavior and created a style of training during the 1990s called 3D-Firefighting together with British fire behavior pioneer Paul Grimwood.
Raffel and Grímwood were both students of Swedish pioneers Krister Giselsson & Mats Rosander who invented European style Offensive Interior Firefighting as we know it today.
In a future article & video, we will demonstrate a more complex dollhouse burn with a dollhouse containing several floors, an attic and a corridor.