A Minor Miscalculation With Explosives
BY Herschel Smith
3 years, 4 months ago
Let’s get this off to an educated start. Here’s a miscalculation for you. I’ve seen engineers do it before despite being taught better in engineering courses.
Let’s say you’re trying to get the cross sectional area of a tube in stress with an inner and outer radius. You cannot use this formula: pi() * (r2 – r1)^2, or pi() * (d2 – d1)^2 / 4. Because that’s not the same thing as pi() * (r2^2 – r1^2). That’s a miscalculation, and it’s the sort that can kill people (or over-design and cost money). I corrected the engineer I saw doing this.
The title of this article is LAPD bomb squad ‘miscalculated” weight of homemade fireworks when ‘controlled detonation’ went horribly wrong destroying armored truck and leaving 17 people injured.
Los Angeles police have admitted their bomb squad ‘miscalculated’ the weight of fireworks before a planned controlled explosion which went wrong last month, destroying the team’s armored truck and leaving 17 people injured.
[ … ]
The vehicle has an iron chamber which is designed to contain 25 pounds of explosives, and officers estimated they were putting in 16.5 pounds in to it, LAPD Chief Michel Moore said Monday.
But investigators later weighed the remains of the explosives and calculated that there must have been about 42 pounds of fireworks loaded into the device.
The resultant catastrophic failure of the armored chamber sent a plume of fire into the air, injured 17 people and shattered the windows of nearby buildings.
Chief Moore gave the update the investigation on Monday morning at the LAPD Headquarters and said an ‘apparent miscalculation’ and ‘human error’ led police to overload the containment truck.
“Apparent miscalculation.” He uses those words. I do not think he understands what it means, and it makes me wonder if these folks have ever calculated anything in their lives.
If they tried, could they drive the intelligence quotient of LEOs any lower than it is right now?
And why couldn’t they have driven the truck into the middle of a field rather than do this on a city street?
Tip: WiscoDave.
On July 21, 2021 at 5:16 am, Bert said:
“And why couldn’t they have driven the truck into the middle of a field rather than do this on a city street?”
The short painfully simple answer
WE allow the concept of “qualified immunity” to continue standing.
On July 21, 2021 at 6:25 am, Mark Matis said:
Better yet, why couldn’t they have put their entire bomb squad in the vehicle along with the fireworks???
The city would now be better off!!!
On July 21, 2021 at 8:32 am, Fred said:
Technology isn’t always better. People have been blowing things up for centuries. When you do it, you do out in the middle of nowhere. There being several deserts proximate to LA, they have no excuse.
And besides, having blown up things, I can tell you that it’s a lot funner to watch it. Why would anybody blow something up in a box where you can’t see it? Not only are they stupid, but their not even normal men. What’s the point of a gigantic explosion that you can’t see? Well, nothing.
On July 21, 2021 at 9:03 am, Rocketguy said:
I am in the process of spec-ing a reusable intentional detonation chamber for disposal of a collection of old energetics that have been deemed unsafe for transportation. Likely very similar to what they reference in the article as some of the chambers are designed for portable use and mounting in b=vehicles. These chambers typically have ratings based on quantity/type of explosives and service life. It’s generally something like x lb – single use (!!), x/2 lb – 10 uses, x/4 lb – 50 uses, etc, etc until you reach a low number that is basically infinite uses. The use of said equipment should be limited to competent professionals…missing the “estimate” by 2.5x and subjecting the equipment to a 70% over-test ain’t that.
I would also have some questions about the chamber rating vs what I would assume was black powder in the fireworks. The 25 lb rating is typically for high-explosives like PBX, RDX or Tritonal with much higher velocity detonation than black powder. I wouldn’t be shocked if the 42 lb post-incident estimate was also low.
On July 21, 2021 at 9:17 am, George 1 said:
Many police personnel today cannot even be counted on to obtain a correct address for felony warrants. Is it any wonder that they have problems using weight measuring equipment?
On July 21, 2021 at 10:30 am, The Old Freedom Fighter said:
Had this been 1951 instead of 2021, the odds of this happening would have been very unlikely. Back then, you actually had men who knew what they were doing. More proof intelligence levels are declining along with the rest of civilization.
I’m curious to know how much this going to cost the city of LA, or more specifically, the taxpayers. No doubt, the b-squad members will be exonerated & the fireworks manufacturer charged and held liable!
On July 21, 2021 at 12:32 pm, Sisu said:
Agree with all above. I add my understanding that the overriding problems occurring in major metro area police departments across the country are (i) lowering of threshold academic standards (both aptitude and education), and (ii) the resultant “group think” used to determine the “best answer by consensus”.
Thus the “human error” was just another consequence of the devolution of “policing” in American cities.
Most recently led by the stupidity of the primacy over skills and competency of “profiling” (politicians can – you can’t) in order to have the complexion of LE represent the complexion of the community they work in. … This “profiling” approach necessary to compensate for LE unions over the last 60 years wholly eliminating any requirement that their members live in or near the communities they patrol; thus ensuring “we / them” relationships.
Other requirements that have been abandon are “communication skills (English as a first language)”, appropriate pre-disposition to “serve the community”, de-escalation training, continued physical fitness, hand-to-hand combat, firearms competency (but give them the weapons needed to occupy and control enemy territory).
The result is as often noted on this site – LEO who all too frequently only know violence as a means to asserting “their” authority; emphasis on “their” not “lawful” given the unlawful, court construct of “qualified immunity”, and “case law” asserting LEOs have “no duty to protect” individuals only “the public at-large”; whatever that might mean – obviously Portland, Chicago, New York, Baltimore, Kenosha, … are not occupied by the “public at-large” and thus are not entitled to protection, nor was the relatively small captive group of minors attending Florida’s Stoneman HS; no “special duty” despite the legally compulsory requirement to attend.
And, now un-American politicians and DAs (who do not believe in the Constitution or American principles of “freedom”, “liberty”, “restraint on government”, …) targeting LE on behalf of criminals, anarchists, drug addicts, sexual predators and perverts, the mentally ill, illegal aliens, …
P.S. I suspect LAPD chose to destroy the fireworks on site in order to ensure said fireworks didn’t wind up in the hands of the LEOs who found them. …
On July 21, 2021 at 1:47 pm, Matt said:
Meanwhile we also have those who want to inform you that it is racist to demand correct answers on math problems/tests.
On July 21, 2021 at 2:42 pm, Brad said:
He must have been using his phone app.
On July 21, 2021 at 2:43 pm, Fred said:
@Sisu, Re “communications skills”
I do worry about contact with police that can’t communicate. Even if English is their primary language the average vocabulary is down from 2500 words a century and a half ago to 700 words today and still dropping. My habit of speaking in 3 syllable words, often 2 or 3 in a row, could get me arrested for “resisting arrest” simply because the po po can’t understand spoken English.
Thus, the imperative grows: never talk to police.
I contact dozens of random people usually every week to discuss the things of God, and offer to share the Gospel of Jesus Christ. I have to define simple words sometimes even to adults. Some young adults who share the Gospel have told me that they are asking the people they contact to read and explain verses back to them, just to make sure the contact can even understand what the simple English of the bible is relating. I’m not even talking about third worlders, I’m talking about the grown grandchildren of boomers.
On July 21, 2021 at 2:52 pm, Herschel Smith said:
@Fred,
To your point, Douglas Wilson had a debate on the campus of Indiana University about homosexuality, gay rights, gay marriage, etc.
After listening to the debate (all of it), I had concluded one thing: young people today cannot even understand complicated English. Doug would make a point that was clear to me (whether they agreed with it or not), and yet it was unclear to the audience. Further, they could not make logical connections, interrogate the information for contradiction (or lack thereof), or make immediate inference (or syllogism).
The lack of critical thinking skills was frankly frightening.
On July 21, 2021 at 5:19 pm, Survivormann99 said:
These cops must have been Common Core grads.
Maybe the problem was that “Maff is hard.”
On July 21, 2021 at 5:45 pm, xtphreak said:
Is 25 lbs of black powder the same explosive force as 25 lbs of Semtex?
doesn’t seem to be the correct parameter to judge if the chamber will hold.
Why does “…‘apparent miscalculation’… ” sound like “accidental discharge”?
“Accidental discharge” really means “Negligent Discharge”.
“…‘apparent miscalculation’… ” means a lack of basic math skills.