How many disasters and faillures from bad material choice? 4

[enginesrus]

I can think of and have seen many failures, due to engineers choosing the wrong materials to make or build the devices from.
Lets start naming some.
I'll start out with the use of flammable magnesium castings in old aircraft engines.

 

[TugboatEng]

Another good example of a material cause, RB.

Here is one from my industry. A substitute caulk was used where an adhesive polyurethane caulk should have been.

https://gcaptain.com/ntsb-releases-tall-ship-bounty-report/

 

[enginesrus]

The automobile industry is full of examples of use of the wrong material, and I am talking in the engine and powertrain components.
It has helped contribute to many of the failures and lawsuits that have plagued the auto industry for years now.
The Takata debacle is a good example, the others I mention always seem to raise eyebrows, such as the over use of aluminum that has replaced cast iron and steel in many applications, yes a weight issue and manufacturing cost issue, but when the recalls and bad press hits, what was saved? Then the real design failure plastic, with all the talk of ridding us of plastic straws and forks, I just can't understand how the excessive use of that material in the auto industry is totally ignored. What cracks and breaks first in or on an engine? The steel parts or the plastic parts? Nothing better than a crispy plastic thermostat housing, or a crispy radiator tank, yeah just more junk for a land fill.

 

[IRstuff]

Didn't that first collapse of a Big Dip panel kill a motorist?

yeah just more junk for a land fill

That's machts nichts isn't it? When a car is crushed into a small solid cube, what's plastic or steel is mostly irrelevant

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[JohnRBaker]

Yes, speaking of poor material choice in an engine part, my wife had a new 2000 Cadillac Catera. Now this was the first year of the Catera (they don't use that name anymore, I think the equivalent model is the CTS or perhaps the CT5) and it was actually a rebadged German-made Opel Omega. Now this was the first co-called 'luxury' car that we had ever owned (my wife now drives a 2018 Mercedes C300) and it was a fun car to drive as it felt like a German sports car, good gas mileage and brakes that could stop on a dime. And it was a great car to drive out on the open road for long trips. This was in the days before MP3 players and it had a 12-disc 'jukebox' CD-changer in the trunk. I had my 12-disc cartridge and my wife had hers and on a long trip we always had good music to listen to (this was also before satellite radio and in those days, out in most parts of the country, it seemed like every other station was playing Rush Limbaugh). The only problem was that it needed about 25 more horsepower as it had an automatic transmission, AC and about 500 pounds of extra stuff like insulation and other things not found on an Opel Omega in Germany (they had to 'Americanize' it).

Anyway, we had had the car for little over two years when I was driving it one day (luckily I was stopped at a light waiting to turn left) when the engine just stopped. It not only stopped, it totally seized-up, like a rock. Now this was a V6 with dual-overhead cams, driven by a serpentine 'cog' timing-belt arrangement, which was fine. The problem was that this belt arrangement was inside that same housing as was the serpentine multi-V belt used to drive the engine accessories (AC, alternator, power-steering, etc). Now the face of the pulley on the belt-tensioner for the accessory belt had a thick layer of some sort of elastomer, perhaps polyurethane. Anyway, this material apparently had dried-out, and it eventually came of causing the accessory belt to come off. Now under normal circumstances, this would not have been a big deal, except that the belt got caught in one of the 'cog' wheels on the overhead cam drive causing the timing-belt to either break or jump off, thus causing the engine to seize. Now Cadillac was very good about fixing it, totally under warranty, just that it took about a month as they had to get a new engine from Germany because apparently when the cams stopped moving, the engine didn't, and at least one valve collided with a piston. Apparently what had happened was that the elastomer, or the adhesive that bound it to the tensioner pulley was not suitable for a hot, dry climate like SoCal, but rather more for what you'd expect to find in Europe (about a month after we got the car back we got a recall notice to replace the pulley, of course by then we already had a new pulley, courtesy of the new engine). It had taken about two years before they started to come apart. When I asked the service manager about this the next time we had the car in for service, he mentioned that yes, this had first been noticed by owners in places like Arizona, New Mexico and Nevada, but that ours was one of only a few incidents in SoCal (but we had driven the car to Texas at least twice and once to Michigan) but that it was rare that the failed accessory belt caused the timing belt to come off/break, however, the new engine now had a 'baffle' between the two belts.

John R. Baker, P.E. (ret)
EX-'Product Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[ACtrafficengr]

The Charlotte Speedway footbridge collapse in 2000. The wrong grout additive was used, which corroded the prestressing tendons.

http://www.nace.org/CORROSION-FAILURES-Lowes-Motor-Speedway-Bridge-Collapse.aspx]Link[/url]

My glass has a v/c ratio of 0.5

Maybe the tyranny of Murphy is the penalty for hubris. -

http://xkcd.com/319/

 

[cvg]

https://www.concretepipe.org/wp-content/uploads/TusconandPrescottFire_ePipe016.pdf

 

[drawoh]

I don't believe either the Titanic or Challenger accidents or directly caused by poor material choice.

Titanic was designed such that any two adjacent holds, or the first four holds could be opened up and the ship would remain afloat. She lightly grazed an iceberg, and it opened up the first six holds. What are the requirements for modern liners and cruise ships?

Perhaps she would have survived impact with a Teflon berg!

--
JHG

 

[IRstuff]

I think the Titanic had a slightly different issue in that the holds were actually interconnected, which allowed undamaged compartments to flood through interconnected spaces above the waterline. Had these spaces been sealed, the ship might have maintained buoyancy longer, at least allowing more passengers to escape.

Nevertheless, there was an issue with the rivets possibly being substandard in slag inclusions

https://www.materialstoday.com/metals-alloys/news/what-really-sank-the-titanic/

https://archive.org/details/whatreallysankti0000mcca

which resulted in them being more brittle than required. This might have allowed the bulkhead plates to be less resilient to the collision that occurred

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[drawoh]

IRstuff,

My understanding is that somebody worked out that if some bulkheads had continued up to the main deck, Titanic would have remained afloat. Why would anybody spend money to grossly exceed requirements.

I don't think they had mysterious structural failures in 1912. Nobody else's rivets failed. I doubt that Titanic's were bad. Titanic displaced something like 60000[ ]long[ ]tons and she was travelling at 20[ ]knots. The rivets were not match for that sort of kinetic energy. Structural failures started in the two world wars when they brought in new, untrained people to implement new technology.

--
JHG

 

[IRstuff]

The rivets in question were forged, and depended on the quality of the workers that did the work, so it was possibly a one-off, since its sister ship didn't have that problem despite several collisions.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[epoxybot]

Oakland City Center - City Square outdoor shopping mall. Nearly the entire ground level and elsewhere multiple floors of the exterior are clad in 11 x 11 tiles. Tremco polyurethane caulk was used for the grout lines. All of the caulking has reverted. This was less than a decade after it was completed in the early 90's. I have no idea whether it has been replaced.

Another problem is all the ground level shops have suspended/floating floors. The top floor of the parking garage used upturned beams, turning the ground floor into a series of 2 foot deep wells that fill with water; requiring occasional remedial dewatering and floor replacement.

 

[AusG]

The biz of the rivets and the plate metallurgy in the Titanic has kept entire websites full of Titanic-obsessives busy for decades. The NIST study on some recovered materials is a good bit of work.

 

[TugboatEng]

Compare the Costa Concordia to the Titanic. It took the Titanic quite a long time to sink. This is because it sank due to down flooding and not the initial flooding of the holed compartments. The contribution of the rivets is moot at that point.

 

[GeoEnvGuy]

Go into any treatment plant, refinery, or mining mill and you will find leaky valves.

 

[JohnRBaker]

Probably true for most any ship as well (Tug can confirm this).

John R. Baker, P.E. (ret)
EX-'Product Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[MotorCity]

A wood stove. I hear this all the time and think "hmm, must be a one time use stove" when they actually mean a "wood burning stove"

 

[JohnRBaker]

Yes, my mother cooked on a 'wood burning' stove, even well after I left home to attend college in 1965. In fact, when she sold the house in 1994, the stove was still there and in use. Not sure if the new owners kept it or not.

This picture was taken the day we closed the deal to sell the house:

July 1994 (Minolta XG-M)

Note that the apartment size electric stove was used only in the Summer. The rest of the year, my mother cooked all the meals on the much larger 'wood burning' stove. Note that you put the wood in the panel that lifted on the left end of the stove and the panel on the right was where the tank of water was, so you'd always have hot water. We didn't use that feature much, but it was there just on case.

John R. Baker, P.E. (ret)
EX-'Product Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[TugboatEng]

No valves leaking in our fleet. We don't have regular flows off and on the vessels as we use keel coolers. All flows are otherwise intermittent. This has caused us great difficulty as there is no scouring and all of our valves did get dirty and did leak. I introduced butterfly valves and now the cost is low so we simply replace them before every inspection. Don't get me started on minimum valve size.

As for the wood stoves? My parents found themselves quite fortunate after the Loma Prieta earthquake as their stove was dual fuel and could run on propane and wood.

 

[thebard3]

A wood stove.

That's kind of like a hot water heater.

Hot water doesn't need heating. -- George Carlin

Brad Waybright

The more you know, the more you know you don't know.

 

[Comcokid]

This thread is titled "How many disasters and failures from bad material choice?"

But what is more interesting is Engineering Failures that resulted from too good a material.

Early in the Apollo program there were failures in titanium tanks used to store nitrogen tetroxide oxidizer for use in the lander. This lead to a massive investigation into the material, welding, crack analysis, test procedures, etc involving many contractors and sub contractors. Nitrogen tetroxide and aerozine 50 were used to fuel engines and thrusters in many other parts of the entire Apollo system, and similar fuels in Gemini. Many failed tests could not be duplicated a second time. Some tests that passed at one facility would not pass elsewhere. Everything was at risk. Similar systems in missile programs didn't have issues.

It was eventually discovered that a major supplier of the nitrogen tetraoxide, knowing it was for the moon program, super-refined the oxidizer and removed most of the trace contaminants. Specs called only for a max level of contaminates. Turns out that a very small amount of NO and nitric acid were needed to keep the pure oxidizer from eating welds in the tanks. Problem was solved by specifying a minimum amount of these trace contaminants.