After Being Reborn, I became a firefighter again?

Chapter 649: Chapter 460: It All Starts with the Screen of Smoke

"A comrade has fallen because of this."

That statement, powerful enough to shock, had earned Fang Huai the silence of the Instructor and the solemn attention of everyone present.

So, no one interrupted, and Fang Huai’s voice continued.

"Modern building fires are different because buildings are taller, more compact. There are fewer breezy bungalows, many buildings are surrounded by limited space, with fewer external ventilation doors and windows, mainly of the limited ventilation type fire scene. Furthermore, the burning energy contained in building and decorative materials vastly exceeds that of the past.

From this perspective, the time has come for our old fire-fighting methods to change.

How to control the inflow of oxygen, to manipulate airflow to alter combustion conditions, is becoming an increasingly critical issue."

As Fang Huai spoke, the scenes of the day Little Black fell kept flashing in his mind.

The three-story building with an additional mezzanine had a large interior space with partitions, and only three windows, which were not fully open.

A typical ventilation-limited fire scene.

Now, he thought, if they had closed the door to reduce the inflow of oxygen, the fire would have definitely diminished, even though the people inside would be in great danger. But a short period of hypoxia wouldn’t be deadly.

At least not more dangerous than the temperature rising rapidly. freewēbnoveℓ.com

But what was everyone doing that day?

When he arrived, the door was wide open, Little Black was inside attacking the fire. Hao Chengbin and Zhao Jinchen were at the door controlling the temperature with their water guns in full spray.

To maintain a reduced temperature pathway for those attacking the fire from the inside, this is what’s currently known as "door control."

At the time, no one thought anything was wrong because that’s what everyone had learned: the water gun is for cooling people down to create a safe passage.

But everyone, including Fang Huai, overlooked why a limited ventilation fire scene, with supposedly insufficient oxygen, could burn so fiercely without any signs of weakening.

It was because of that open door, and those two water guns spouting water, continuously supplying a torrential downpour, insanely pushing air inside with water pressure!

They thought they had left a door open as a retreat for Zhou Yong, but that door became the harbinger of his demise.

"In addition, in our past understanding, we considered breaking in as the way to fight a fire from inside and ventilation as opening windows.

In reality, any additional openings in a fire-affected structure will increase the heat release rate, and the door is also a ventilation point. The presence of a single ventilation point will change the smoke path.

Especially under the circumstance of pressured air entering, the speed of air movement can suddenly increase by more than tenfold!

The smoke surges in disorder, pouring out towards the door, and firefighters entering from there – what kind of high-temperature and toxic environments would they face? How many degrees of scorching would all the combustible materials in the path endure?

Therefore, ventilation and smoke exhaust must consider the strength of the first intervention forces and align with firefighting commands. Unauthorized ventilation can quickly lead to the loss of control over the fire scene and endanger personnel.

The door must be controllable, open briefly for ingress and egress, and then immediately closed. When smoke needs to be vented, open windows for one-way exhaust to create a stable, unidirectional ventilation path. Otherwise, the smoke is uncontrollable, and so is the fire.

This is the true knowledge of door control.

Not just simple door control, but control over high-temperature smoke and oxygen!"

As Fang Huai spoke, he wanted to slap himself. frёeweɓηovel.coɱ

Everyone said that after Zhou Yong went in, the support group continued to cover with water, and the fire picked up aggressively, as if welcoming him.

It was probably because air was forced back into the fire scene from the door, creating an internal pressure which turned the smoke chaotic again.

Actually, on that day, there was no need for him to enter desperately. If only he had closed the door upon arrival, when Zhou Yong made his first interior attack, leaving just a slit for the water gun, and then cooled down the second-floor ceiling entirely. The steam might have scalded Zhou Yong briefly, but with the oxygen reduced and continuous cooling, the fire would surely have taken a different direction!

By handling it that way, by the time Zhou Yong went in the second time, the survival conditions inside would have changed qualitatively, maybe there wouldn’t have been any more danger, maybe he wouldn’t have needed to rush out, and he could have just waited for his comrades to rescue him.

The apparent errors caused by this lack of knowledge filled Fang Huai with deep regret.

Zhou Yong was brave, but he didn’t die from bravery, he died from ignorance.

The ignorance of his comrades.

But the comrades didn’t want to be ignorant; they lacked the proper channels to learn the correct knowledge.

Fang Huai’s words today were intended for the 46 Commanders present to hear, and even more so, for all the school’s Commanders to hear.

The understanding of smoke flow in today’s world hasn’t formed a detailed theory anywhere, so naturally, the Instructor could not argue and had to listen. But the future Commanders beside him were obviously more interested.

A curious trainee broke the silence.

"So you’re saying we shouldn’t just let the water bloom at the door?"

Hearing the question, Fang Huai snapped back to reality and said:

"It’s not that we can’t spray, but that the pressure shouldn’t be too high, and while sweeping the door with water, doesn’t a high-pressure, wide-spray also push air rapidly inside?"

"But from the time we were new recruits, we’ve been taught to carry two guns into the fire scene, the front one blooming and the back one in a straight stream. The blooming one covers the attack to prevent flame shock, while the straight stream targets the fire source. It’s like the One Hundred Meters Ladder Attack Drill, and it’s been very useful for so long. If we’re not allowed to let it bloom at the door, who will cover the interior attack?"

The eagerness to learn brought a slight smile back to Fang Huai’s face:

"While covering, we should use door control tactics to make probing entries. After reducing the temperature with water through the doorway, it’s possible to operate from the inside, isn’t it? The methods of door control tactics and transitional attack should be tailored to the specific situation, which I believe Instructor will teach."