Photo Information

Gunnery Sgt. Jhimelle Sepulveda, training chief with a fire fighting unit here, emerges from a fire training facility during an exercise conducted by the Camp Pendleton Fire Department and the Marine Corps Air Station Camp Pendleton’s Aircraft Rescue Fire Fighting unit on a controlled burn training facility at the 25 Area here. The training was designed to teach firefighters how to prevent rapid combustion of burned materials in rooms and structures. "This is good training because we don't normally get to experience this type of situation when dealing with burning aircraft," said Sepulveda.

Photo by Sgt. Christopher Duncan

Firefighting Marines hone skills to prevent flash fires

8 Sep 2014 | Sgt. Christopher Duncan The Official United States Marine Corps Public Website

A canister bursts into flame as a thick cloud of brown smoke quickly fills the room. Students sit on the ground and watch with anxiety as the fire spreads, devouring the oxygen in what has now become an oven. The flames skim up the walls of the room and roll across the ceiling like waves of liquid fire. Firefighters sit, prepared to combat the blaze. The fire is a mighty foe, but it’s up against a strong challenge. These aren’t just firefighters, they are also Marines. This was the scene during a training exercise conducted by the Camp Pendleton Fire Department and the Marine Corps Air Station Camp Pendleton’s Aircraft Rescue Fire Fighting unit at a controlled burn training facility at the 25 Area here.

“This is a train-the-trainer exercise, designed to teach firefighters how to identify the hazardous conditions that can allow rollover and flashover to happen, whether in a house or a large frame aircraft,” said Master Sgt. Raymond Secoy, staff non-commissioned officer in charge of the ARFF.


Rollover is when burn products are ignited due to the introduction of oxygen and combust along the ceiling.

“You can see it run across like a wave until it slowly banks down the other side,” said Staff Sgt. Christopher Garbutt, a material chief with the ARFF. “Rollover leads to flashover and the heat fills the room, making it all one temperature, much like an upside-down oven.”

A flashover is an oxygen depleted still-burning fire. When oxygen is introduced to the burned products, it ignites and it rolls across the ceiling. 

“It’s called flashover because it flashes from the spot of the fire along the ceiling where combustible products are and it changes the thermal layering in the area, making the room all one temperature at the same time,” said Garbutt. “Your survivability rate is nil at that point.”

The instructors learned to teach their future students how to mitigate the chances of a flashover and rollover and what to do if they occur. 

“The general school of thought is to ‘stay low to the ground’ during a fire, which is right, but the flashover raises 200 degrees at the floor level to 1,300 degrees from floor to ceiling in an instant,” Garbutt explained. 

During flashover, a fire may look extinguished because it is oxygen depleted. However, if firefighters improperly ventilate the room they introduce oxygen to the fire which causes rapid combustion and super heating.

“They would think the fire was out, take off their gear or start performing another part of the firefighting operation - like salvage or overhaul - not realizing that some of their duties were actually feeding a fire they didn’t know was behind a wall or in another room,” Secoy added. 

Secoy explained that there are four stages of fire. The incipient phase is what starts the fire, the growth phase is where the fire begins to spread and rolls up the wall, the next is the fully developed phase and the last phase is called decay where a fully formed fire is dying down because everything is already burned.

“Everything has an ignition point, meaning that they combust when they get hot enough,” said Secoy. “A flashover happens between the fully developed and decay stages, which causes roll over and death if you’re not aware of what’s happening.”

Secoy said that safety is paramount during the training and it all starts with the small unit leadership; checking the Marines gear and ensuring that it is properly fitted on them and that their air packs are filled and operational. 
While in the trainer they also constantly monitor each other.

“We require a safety vehicle, a large amount of water and at least two hand lines [hoses] for an exercise like this,” said Secoy. “There were 4,000 gallons in the water tanker; the engine truck held 1,000 and we also had a light attack vehicle on site. We used approximately 2,000 gallons of water during the exercise.”


The firefighters sat on the floor during the exercise for safety, to observing the thermal layering of the room through the stages of fire, and to experience the temperature of the room rapidly increase.

The exercise is conducted in a large intermodal container, modified for the training, with one instructor teaching near the fires source and two additional instructors at the front and rear of the structure to control the doors and a lever-controlled ventilation flap inside.  

“The ventilation flap at the top is designed to release super-heated gases to encourage the beginning of the rollover phase so that all of the firefighters can see it,” said Garbutt. “The training facility is two levels. The students, sitting in the lower level, can get a clear view of what is happening as the fire stretches across the ceiling.”

The instructors use plywood, scrap wood and hay is to use as kindling.

“We’re very particular about what we use to fuel the fire, because we don’t want to use material that will make the fire difficult to control,” said Garbutt.

Marines wore proximity suits which are designed to guard against liquid absorption that could potentially burn while dealing with spills. 

“We were able to tell that the training facility got up to 1,600 degrees during the exercise and as aircraft fire fighters there is the potential to encounter fires are hot as 2,000 degrees,” said Secoy. “The suits can take up to approximately 2,000 degrees of heat.”

They are also equipped with a self-contained breathing apparatus that contains a canister of oxygen that allows up to 60 minutes of breathing time. 

“We do air pack checks, air bottle checks, we have two active hand lines [water hoses] on the inside and one on the outside on standby,” said Garbutt.

Shift workers do daily gear inspections to ensure the equipment used for the exercise is fully functional for game day.

“Being able to do this in a safe and controlled environment builds the Marines confidence,” said Garbutt. “Confidence in their gear, tactics and in each other is important. That can save their life.”

The simulation can be run three to four times a day with six students per evolution from various units.

The Marine Wing Support Squadron, Camp Pendleton Air Station, and civilian federal firefighters will also be able to use the system to meet their training requirement.

“We have mutual aid agreements with base fire and they had four or five instructors go through the trainer with us,” said Garbutt. “The students said they thought the training was invaluable.”