Engineering Disasters

[Hornbein]

It's always nice to read about other people's major screwups.

 

[jedishrfu]

I remember some of those stories, but I never heard the actual horror stories that caused the recall.

One toy not mentioned in this video was Clackers. It consisted of two acrylic balls attached to a common string with a ring halfway between them.

Kids would grab the ring and begin moving their hands up and down to make the clackers hit each other, but before long, they started doing it so forcefully enough that the clackers would hit on both the downswing and the upswing.

The result was that some clacker balls shattered, and the kids and their nearby friends often got hit by these super-sharp acrylic shards.

 

[difalcojr]

Little kids will swallow or try anything small, put it in their mouth, even if it's not colored. I swallowed a penny and another time a nickel on a dare when very young. I bet some of those 5,000 uranium-238 rocks got taken out of the bottle, smashed up, and tasted, eaten, by some curious little kids. Magnetic buckyballs were really lethal!

 

[difalcojr]

Kids would grab the ring and begin moving their hands up and down to make the clackers hit each other, but before long, they started doing it so forcefully enough that the clackers would hit on both the downswing and the upswing.

Same principle, maybe, with the paddle ball, though not too dangerous. Get it going really fast, and it gets a little tilted, misses the paddle on the backswing, and bonks you in the head or body. Remember that happening; fun, though.

 

[difalcojr]

 

[DaveE]

I'll vote for the Hyatt Regency walkway collapse in KC, 1981. It killed 114 people and injured 216.
Maybe not the worst disaster, but the simplest to understand once you read about the cause. A deadly misunderstanding of basic physics and unauthorized modifications of the engineering design.

Dunning-Kruger on display, one drawing says it all:

 

[jedishrfu]

What about the escalator failure in Italy in 2018?



Football fans of a Russian team took the escalator going down. Without warning it began to accelerate injuring 24 people.

https://en.wikipedia.org/wiki/2018_Rome_escalator_accident

The accident was traced back to shoddy maintenance where certain protective systems were intentionally disabled because they would stop the escalator periodically requiring yet another maintenance visit. Some maintenance records were forged as well.

 

[bob012345]

Brand new bridge collapses in China;

https://www.nbcnews.com/world/asia/nearly-2500-foot-long-bridge-collapses-china-rcna243388

 

[Gavran]

Top three:
Chernobyl, the Bhopal Disaster, and the Titanic.

 

[Greg Bernhardt]

I remember this local disaster
https://en.wikipedia.org/wiki/Big_Blue_crane_collapse

 

[nsaspook]

 

[Astronuc]

I remember this local disaster
https://en.wikipedia.org/wiki/Big_Blue_crane_collapse

I have visited Lampson's yard in Pasco, WA. They have a very large crane!

In the article,

Following an investigation by the Occupational Safety and Health Administration, it was determined that the crane was outside of the design specifications required for both load and wind. MHIA calculated the effects of side winds on the crane itself. However, it failed to calculate the load. Additionally, the king pin was discovered to not have been installed nor maintained properly. Lack of coordination between contractors was also blamed for the incident.

Negligence! Preventable!

 

[Astronuc]

It's always nice to read about other people's major screwups.

The point is to learn and not repeat.

 

[Hornbein]

I'll vote for the Hyatt Regency walkway collapse in KC, 1981. It killed 114 people and injured 216.
Maybe not the worst disaster, but the simplest to understand once you read about the cause. A deadly misunderstanding of basic physics and unauthorized modifications of the engineering design.

Dunning-Kruger on display, one drawing says it all:
View attachment 367402

Huh. I guess the vertical supports weren't long enough and they had to do something. I confess it took me a while to figure out what the problem was, so I would have made the same mistake.

My Dad had some people build the walls of his log cabin while he went away for the weekend. On his return he found they'd irreparably screwed it up. The workers had to make a similar decision and went the wrong way. I learned from that to never let anyone work on my place solo.

 

[russ_watters]

Huh. I guess the vertical supports weren't long enough and they had to do something.

They were threaded rods and the contractor didn't want to take the time to thread the nuts up 15 feet of rod. That's why they asked for the change.

 

[QuarkyMeson]

Chinese factories scamming their customers? A tale as old as time.

Lawn darts are also back, not they're just made of plastic and have blunt ends.

 

[difalcojr]

Lot of dam disasters. Biggest wavefront I've ever seen in this video:
This is a fake video. Dam has not collapsed. Got fooled.
Not as big as this one was supposed to have been, though, with no video of this event at failure. Wave generated from a landslide into the dam, the displacement water wave over the top of the dam with a height of 200m, almost as tall as the dam face, in Italy. Oct.9,1963, nearly 2000 killed, 487 children.
https://en.wikipedia.org/wiki/Vajont_Dam#:~:text=excessive quote]-,Landslide and wave,-[edit]
https://intrieste.com/2025/10/10/th...ears-later-a-tragedy-that-still-haunts-italy/

 

[nsaspook]

https://tass.com/russia/744766

 

[tech99]

I noticed a contractor making a big mistake whilst tensioning the supporting guys (or stays) of a big radio mast. To do this they placed a Newton force-meter (called a dynamometer) in line with the stay. They then pulled tension on the stay (using a chain puller) until the Newton meter showed the correct tension. So far this is correct. Then they placed a bottle screw in parallel with the Newton meter. Next they tightened the bottle screw with the aim of halving the reading on the Newton meter, so that the tension would be shared between the two legs. Unfortunately, they forgot that tension is shared in inverse proportion to elasticity, so that the reading of the Newton meter fell very little as the bottle screw was tightened. This put enormous tension on the stay. The correct method is to tighten the bottle screw until the Newton meter just drops slightly. Then the stay is being held in its correct position for the desired tension. The foreman noticed something was wrong and rightly stopped and asked what was happening.

 

[DaveE]

They were threaded rods and the contractor didn't want to take the time to thread the nuts up 15 feet of rod. That's why they asked for the change.

Those rods don't seem trivial to make. I would guess you need a fat section in the middle for the thread, or maybe a special clamping sort of nut. I wonder what the original detailed design was. Welded sections?

 

[russ_watters]

Those rods don't seem trivial to make. I would guess you need a fat section in the middle for the thread, or maybe a special clamping sort of nut. I wonder what the original detailed design was. Welded sections?

They are an extremely common construction component, they just aren't usually that long. So common that for smaller assemblies you don't even need a structural engineer, there's books of standards for things like ductwork, piping and small equipment construction/support. This commonality probably contributed to complacency about the construction.

Note; they are all thread. So they are often called allthread (might be a trade name):

https://www.fastenright.com/blog/what-is-allthread

 

[nsaspook]

With allthread and unistrut you can build just about anything but you do need to tighten the nuts.

 

[256bits]

Boston Molasses flood
https://en.wikipedia.org/wiki/Great_Molasses_Flood
On January 15, 1919, a molasses tank at 529 Commercial Street exploded under pressure, killing 21 people. A 40-foot wave of molasses buckled the elevated railroad tracks, crushed buildings and inundated the neighborhood. Structural defects in the tank combined with unseasonably warm temperatures contributed to the disaster.