Fury 325

Can't they use duct tape? It works for everything else.

RideMan:

That's because the radius provided by the drill eliminates the "sharp" edge at the end of the crack that encourages crack propagation.

Another fun fact about ship building, that's why doorways cut out in the steel have weird round cut outs at the "corners" (they're usually covered by some other material to appear square). It's also why the windows are all cut as round, at least in the corners if not entirely. So in the event that there's some kind of flexing event (read: it's sinking), the ship should for the most part stay together and not see a cracks start at doorways or windows.

I suppose I'll offer my two cents as someone who deals with fatigue testing (often involving welded steel) day in and day out at work. I won't pretend to be an expert on the welding itself, because I'm not, but I can speak to what I see.

Jeff mentioned the phrase "the weld failed" and brought up that the weld itself is often stronger than the steel. Yes, that is a generally true statement about the strength of the weld. And admittedly, it's just poor semantics that have become common nomenclature. In the brief description of failures I am required to write, I often describe a failure as "XYZ weld failed" rather than "crack began near start of XYZ weld."

And Dave is likely correct that the termination/start of the weld is probably where the crack began. I almost exclusively see cracks begin near the beginning or end of a weld, even when they're not a complete circular weld. They typically begin where the weld starts in my line of work, and I believe it has something to do with minute differences in the heat of the weld at the beginning versus end of it. However, the direction we're loading a component can flip flop that if the way the forces act cause more damage around the other end of a weld.

As a whole, yeah, it's likely just a faulty weld that failed due to fatigue.

So they replaced the broken support. Ran 500 test cycles. And it took the NC Department of Labor (handle ride certs in NC) to realize there was a second break?! Horrible look for their maintenance department to have not caught a second break:

https://www.wsoctv.com/news...37EHH22DI/

Is the NCDoL doing NDT though? If the park did their test runs I wonder if it's easier to let the DoL handle NDT for them then contract that out to a third party?

I wonder if due to the scope of the failure someone is doing NDT inspections of welds and joints and found a much earlier development but still an anomaly somewhere worth further investigation? If all of the original superstructure was manufactured around the same time and there was subpar materials or welds I wouldn't be surprised that this extensive inspection would find more issues. In fact I hope it would find those issues.

If anyone seriously thought they actually individually did NDT on every single support weld on that ride over the span of a month I think you're mistaken. Should they have? Maybe but that's a ton of welds in some very hard to reach places with a fairly involved inspection process.

Oh by all means I don't think they would do it on all of them in this time span. Great point.

I was thinking more high stress load points similar to the failure point. Laterals specifically where there would be tension loading. Not that other joints and welds aren't susceptible to failure but I think we'd see a different failure mode if one of those went.