Mobile Live Fire Training Unit Incident Investigation Concludes
Following a training incident this fall that injured two student firefighters and one instructor from the Massachusetts Firefighting Academy, State Fire Marshal Peter J. Ostroskey launched a comprehensive investigation into the cause. “While firefighting is an inherently dangerous job, there is no higher priority than the safety of our students,” said State Fire Marshal Ostroskey.
The incident occurred on the evening of October 4, 2016 at the South Hadley Fire District #2 during fire suppression training inside the Mobile Live Fire Training Unit (MTU). It uses propane gas to fuel three different props (stove, bed and rollover) inside the trailer that firefighters practice extinguishing. The firefighters and the inside safety officer were inside the MTU conducting a fire suppression training evolution when an unexpected ignition of propane gas caused a flash fire and explosion. The explosion pushed open the windows and the rear door of the MTU. The firefighters immediately evacuated the MTU and were treated for minor injuries.
State Police assigned to the Fire & Explosion Investigation Unit were asked to determine the cause of the explosion. The Department of Fire Services conducted a review of the Department of Fire Services/Mass. Firefighting Academy’s (DFS/MFA) operational procedures in general and on that day. The manufacturer of the prop, Pro-Safe Fire Training Systems, assisted investigators in re-creating the circumstances that led to the explosion, and determining steps that should be taken to prevent a recurrence. Mobile training units manufactured by Pro-Safe are used by other fire departments and fire training academies across the country.
The investigators determined that the cause of the training accident was unintentional extinguishment of a pilot light during training operations. This allowed an unknown quantity of gas vapor to build up inside the MTU and when the stove prop was lit, the accumulated gas also ignited and caused an explosion.
The MTU has been used successfully over 3,700 times by the Mass. Firefighting Academy in the past 11 years to provide live fire training opportunities for firefighters in a controlled environment.
The final report has several recommendations for changes and updates to be made by the manufacturer and in DFS /MFA operational procedures to minimize the risk of similar occurrences. These include:
- Have the product manufacturer make certain changes to the prop including:
- Installation of a deflector plate in front of the rollover prop to prevent unintended extinguishing of the pilot flame by errant straight streams from firefighter hand lines;
- Software update to monitor for a decrease of temperature of the pilot flame thermocouple and immediate shut down of a fireplace if a temperature decrease is detected;
- Eliminate the prop’s “automatic mode” to eliminate potential confusion caused when the operator is unintentionally operating in automatic mode. When in automatic mode a fire prop can re-ignite if the prop sensor determines that insufficient water was used on the prop during extinguishment.
- Have ProSafe provide an operator training course. This will help ensure all MTU operators are properly trained by the manufacturer in the safe operation of the MTU.
- Develop a detailed set of Standard Operating Procedures (SOP’s) to make it easier for infrequent operators to maintain proper operational procedures. Develop a quick reference guide to be housed in the MTU control room.
- Implement a more stringent record and report keeping requirement on all live fire training evolutions in accordance with the requirements of NFPA 1403.
Several of the recommendations have already been implemented including the software updates and the elimination of the automatic mode of operation. Installation of the deflector plate to prevent the pilot light from being unintentionally extinguished, additional training by ProSafe, the internal SOP’s and record keeping procedures will be completed before the MTU is returned to operation.