Denny's Sign Failure 8

[dik]

https://www.ctvnews.ca/world/toweri...gh-wind-killing-1-injuring-2-others-1.6239328

Was it removed before an investigation... seems a little hasty.

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So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[dik]

What is the state's professional organisation doing about this? Isn't it their 'motto' to look after the safety of the people?

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So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[CWB1]

The video raises more questions than it provides answers, most importantly how the lousy imagery distorts our arm-chair analysis. The holes in the sign appear to be at the extreme outer edge of the plate, providing no significant bearing surface whereas in the post plate they appear to be more reasonably placed, suggesting the sign plate was cut smaller than the post plate. The bolts appear improperly sized but could simply be necked/stretched, comparing them to the windshield wiper I'd guesstimate the visible portion ~1/2". There's no washer visible and to my eye the video appears to show a standard or possibly even thin hex bolt with heavy-hex doubled nuts on top. The fastener orientation coupled with plate size differences would be ideal for water ingress to cause joint issues. The interesting bit I'd love to squint at more is that the hex head doesnt appear to be deformed suggesting that maybe it didnt pull through.

 

[IRstuff]

the hex head doesnt appear to be deformed suggesting that maybe it didnt pull through.

If that's the case, then A) the holes in the base flange were too big, and B) whatever washer they used to compensate, rusted away, allowing the bolt head to easily pass through the hole. It would seem like these two bolts pulled out first, since the missing bolts probably bent and broke.

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[dik]

My experience is that the hex head would have failed at the U/S of the head... I would not have expected it to be deformed.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Alistair_Heaton]

It's been seen on pipe flanges which is one reason some oil companies banned the use of washers on flanged joints after someone did the same thing and eventually the washer failed and the nut just pulled through the hole.

I was witness to 90kg of flange being launched across Aberdeen bay due to that very issue. Something was even picked up on primary radar going through 1000ft heading towards 8 mile final to the airport. I was too green for anyone to listen (labourer) to why the hell is this a live test not a hydraulic first.

 

[dik]

The hole must have been oversized, I would suspect.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[spsalso]

"The hole must have been oversized, I would suspect."

The holes were likely all made in a fabrication shop, with drawings available. It would seem unlikely that they'd just decide it needed bigger holes.

In the field, however,........

So I'm voting that the bolts were undersize.

Since they've got the two plates with holes in them, and they have at least two of the bolts that were used, and there likely are drawings on file, this should be pretty easy to thrash out.


spsalso

 

[LionelHutz]

The head of the bolt in that middle picture sure looks like it's missing to me. Might be part of a washer or shim still there.

I do agree. They have the pieces. It should be easy to determine what happened.