Consequences due to lack of penetration because of inexperience welders.

[SteveHGraham]

I have written about this before: my dad had two boats which had battery banks located in the bilge. Where the bilge pumps were.

Water comes in. Water over the batteries. No charge. No pump.

[mcostello]

Ever since Eve bit the apple (not blaming anyone) We have made bad mistakes, that's why learning History is important.

[Bill Shields]

which is why the Thresher sank...officially at any rate...

ever since then there has been 100% inspection of welds on subs

[Howard Gorin]

Actually poorly brazed small through hull fittings. Possibly damaged by earlier shock testing.
The failure caused a reactor scram. An attempt to restart the reactor failed. There was negative buoyancy on the boat.
When an attempt to do an emergency blow of the ballast tanks resulted in moisture in the compressed air and adiabatic expansion
freezing the air lines. As the boat settled deeper the hull compressed slightly increasing the sink rate. If there was positive buoyancy on the boat and they used power to drive the boat down a failure like what they experienced would have allowed the boat to surface naturally.

[whateg0]

...
Back in my inspection days on submarine construction, I came across a welder butt welding 1/2" steel plates around the nuclear reactor. He didn't know who I was and when I asked him why there was no bevel for a full penetration weld, He told me "once it is all welded up, no one will know". I reported the incident and he ended up ripping out all the butt welds and redoing it. There was at least several hundred inches of weld.

Unfortunately, there were probably others that were never caught. And depending on the weldor, he could've gone right back to doing it wrong on the next job - just looking over his shoulder more often!

Dave

[whateg0]

... that's why learning History is important.

Problem is, we, as a species, don't learn from history.

Dave

[Bill Shields]

History...what's that????

[mcostello]

The same stuff that is being torn down today.We need the reminders, just like the reminders of old, grand machinery and how it was used. There steered it back to shop machinery related.

[rkcarguy]

I work for a fabrication shop that is AISC certified, and sadly we see a fair amount of this from "low bidder" fabricators that simply don't have enough weld machine and/or experience for the job and we get the ongoing joy of bidding against this shoddy work. Municipalities LOVE to save money and get the lowest bargain basement price they can on projects thinking they are safe with a state bonded fabricator, when in reality they are subjecting themselves to massive liability risk and could be left holding the bag in the case of an accident that kills some people. The fabricator can simply pull the old "What happens if there is an accident? We just change our company name and move to the next town" if you've seen that "it's just ok" carnival ride commercial lol.

AISC certification requires full material traceability clear back to the mill, welder testing and certifications, weld procedure submittals, weld maps in certain instances, keeping of weld inspection records, and so on. AISC audits it's fabricators annually, If you have more than 7 corrective action reports in a year they will suspend your certification.

In this case these hangar doors could have been fabricated overseas and shipped in, and as I'm sure many of you know a lot of other countries don't give a rats behind about quality it's all about doing as little as possible for the money received. Once you've paid the balance of the bill and they go on the container ship and they're yours.