r/CatastrophicFailure

A government official at Zhob Hospital told BBC News that a total of 48 people, including a number of women and children, had been on board when the accident happened.

The cause of the crash is under investigation, but preliminary reports suggest a steering fault may have led the driver to lose control before skidding off the mountain range.

There are many news articles and posts relating to this incident. I wanted to give people a better understanding of what the purpose of the building was, hazards, and potential causes of this incident.

I am a former operator for a different company that manufactured product similar, if not equal to, what was in this building. I can only say what my experience in explosive manufacturing has taught me, and I am willing to answer any questions to the best of my knowledge for anyone curious.

I will preface with this: Explosives are dangerous and not to be taken lightly. The important acronym to know is FISH - Friction, Impact, Static, and Heat. These are the key things to be aware of when manufacturing, handling or storing any type of explosives. Some explosives are highly sensitive, while others need a primary detonation to be set off.

Updated articles state that this was AES's melt/pour building. Melt/pour is the building in which explosives are melted and mixed in kettles based on formulations that determine the finalized product. Once mixed, it is then poured into canisters and/or packaging designated for the type of application in which the formulation is designed. This would be the fluorescent green canisters that were strewn about the site. This product is called a booster.

A booster is an explosive charge used to detonate less-sensitive charges. Boosters use formulations primarily of TNT and PETN. RDX, HMX, Aluminum, and some other materials may be used in addition. These are primarily used in the mining industry, but can be used in applications.

The process involves multiple kettles for melting and combing the materials. One kettle may be a pre-melter, which is used to melt TNT into a liquefied state and could contain TNT throughout an entire shift, work week, or longer if there is no downtime in production. This can then be transferred to other kettles for mixing. If AES's process is similar to what I'm used to, then each kettle would have a designated quantity of hot liquefied TNT ready to mix. TNT (trinitrotoluene) is relatively stable and doesn't degrade in a liquid state. PETN (pentaerythritol tetranitrate) is a crystallized white powder that has a medium sensitivity to friction and static discharge. When mixed with TNT, it becomes what is known as Pentolite. Pentolite needs a primary explosive (detonator or det cord) to work, but can be initiated by FISH. Sometimes a degrading agent can be added, so that over time, the formulation becomes inert.

Each kettle should have its temperature monitored during production and agitation adjusted so that the kettle doesn't create hot spots. They should be heated up using a steam system. They should also have an agitator (think something similar to a propeller blade) constantly stirring the material inside the kettle. If the formulation/materials exceed a certain temperature, it has the potential to release energy (think flash point).

When working within a cast booster production facility, when the kettle lid is closed, operators shouldn't need to wear a respirator if they have a proper scrubber system installed. If the operators are working over the kettle for an extended period of time, a respirator should be required. Operators should also be wearing clothing made mainly of cotton, so that static electricity doesn't build up, along with other PPE like chemical-resistant gloves and face shields.

From here, operators could be located either below or to the side of the kettles when pouring the formulation into canisters. If they are working below the kettles, operators will pour the formulation into canisters, which are then put into a cooling tunnel to solidify. The appearance of which will be off-white in color, and resemble plaster. They are then brought out of the cooling system to inspect and pack, set on pallets, and stored in a finished goods magazine.

Nobody was allowed on site due to secondary explosions, and this was done for the safety of the employees, law enforcement agencies, and first responders. An explosive fire can not and should not be messed with. I was taught that you should not fight explosive fires. So keeping everyone at a safe distance til the explosions stop is about the only thing you could do.

I never felt unsafe working for the company I did when I produced boosters. We had several people that have been there a long time. We went over standard operating procedures, which included exactly how our process worked, which tools we were allowed to use (non-sparking and/or wood/plastic), the temperature of the product in the kettles to maintain safety, when (if ever temp got away from us) to evacuate, and proper PPE. Training was mainly done by the senior operators and always by reading and going over the SOPs to start, before we began any hands on training. We evacuated in the event of any lightning strikes within a 10-mile radius, all while still being able to monitor our kettles remotely to see any fluctuations in temperature and agitation.

If standard operating procedures are not being followed as directed, any number of things could have caused this accident. My experience with things that could go wrong are things such as operator negligence/error (not following SOPs), mechanical failure, electrical failure, unapproved hot-work, electrical equipment being used that is not intrinsically safe, temperature runaway, agitation malfunctioning, steam dropping out, a small spark from maintenance work or operators using non-approved equipment, material handlers using powered equipment in areas not approved for such work, someone not paying attention, debris in raw materials, and even failure to maintain a clean working environment. Things like cell phones, smart watches, etc, should not be brought into the manufacturing environment. An electrical storm could also potentially be a problem, but that didn't seem to be the case on the day of the event in question.

There are risks with every job. At the end of the day, safety is on each and every one of us. Some rules or procedures may seem silly, but they are there for a reason. Don't take safety lightly. This is something that I have learned to be very grateful for and have taken a lot more seriously with the various jobs I have worked. OSHA may get a bad reputation sometimes because of all the rules/regulations they have in place for various work environments, however, they update and create new regulations based on hazards and potential hazards in order to keep us safe.

I do not believe this incident to be any act of sabotage, foul play, or attack. This accident is devastating for those involved, their families, and their community. I only hope that the law enforcement agencies can come up with how a better glimpse of this happened to provide some closure, and ensure that regulations are set in place and/or enforced so that this doesn't happen again.

I work at an aerospace manufacturing shop specializing in LPBF metal printing for rotating detonation rocket engines. With guidance from propulsion engineers, I designed, printed, and post-processed my very own solid rocket motor from scratch.

If you want to see a CATO up close and personal, and learn what goes into metal additive manufacturing along the way, check out my trailer and subscribe. The first full video is coming soon.