USN CVN-78 Thrust Bearing Trouble

[ChuckMK23]

Maybe a resident SWO can explain what a 'thrust bearing" is and why its inmoportant - apparently my employer f*cked it up!

https://www.bloomberg.com/news/arti...w-failure-at-sea-as-u-s-navy-seeks-more-funds

 

[exNavyOffRec]

Maybe a resident SWO can explain what a 'thrust bearing" is and why its inmoportant - apparently my employer f*cked it up!

https://www.bloomberg.com/news/arti...w-failure-at-sea-as-u-s-navy-seeks-more-funds

or an engineer on a CVN steam moves the turbines that drive the reduction gears that drive the main shaft, the thrust bearing takes the thrust from the screw on that shaft and transmits it to the ship itself to make it go.

up until now I have not heard of one failing on the Nimitz class so I wonder if they are using a different brand, or if it is just a simple manufacturing error.

 

[nittany03]

or an engineer on a CVN steam moves the turbines that drive the reduction gears that drive the main shaft, the thrust bearing takes the thrust from the screw on that shaft and transmits it to the ship itself to make it go.

up until now I have not heard of one failing on the Nimitz class so I wonder if they are using a different brand, or if it is just a simple manufacturing error.

Article seems to imply a manufacturing error by Get Everything . . . I mean General Electric.

 

[exNavyOffRec]

Article seems to imply a manufacturing error by Get Everything . . . I mean General Electric.

Something must be different from Nimitz class to the Ford as far as the bearing manufacturing.

How the hell do you screw up something you have manufactured correctly for 40 plus years???

 

[hlg6016]

I thought the whole purpose of shakedown cruises was to reveal problems like this and get them fixed? Or am I just making too much sense?

 

[picklesuit]

Always strange to me when they fuck up something they were doing correctly for years.

Reminds me of 2002/2003 when Ford went from the 7.3L Diesel engines (bulletproof machines) to the 6.0L that was apparently set on “self-destruct.”

Took them years to recover and they lost a lot of trust from the public.

http://autoweek.com/article/car-new...stroke-woes-anger-buyers-drive-warranty-costs

Hopefully GE is smart enough to jump on the grenade and eat some costs, although with so few companies making specific parts, they may not have much competition...

 

[hlg6016]

Ships or trucks, introducing a "new and improved" model pretty much brings with it glitches that has to be worked out.
That's from a guy who's on his 3rd Explorer/Mountaineer model.

 

[Pags]

I thought the whole purpose of shakedown cruises was to reveal problems like this and get them fixed? Or am I just making too much sense?

This. Ships conduct shakedown cruises to identify issues such as this and have PSAs to fix issues. There’s a limitation to how many issues you can identify without getting underway so the fact that this issue is coming to light during shakedown shouldn’t be overly surprising. What is more surprising is that someone would make a big deal out of issues found during a shakedown. A shakedown that resulted in no issues found would make me suspect that the testing wasn’t rigorous enough and that issues will crop up post PSA when they’re harder to fix.

As to why it broke there’s also any number of reasons. Perhaps the guy who used to make them retired and the new guy isnt as good. Perhaps the new guy is a robot and isn’t as good or is maybe too good. Perhaps they got the wrong material from a sub. Or a myriad of other potential reasons. I bet there’s a group doing an EI on the piece to identify failure modes and drawing up an Ishikawa diagram to identify root causes.

 

[exNavyOffRec]

I thought the whole purpose of shakedown cruises was to reveal problems like this and get them fixed? Or am I just making too much sense?

shakedown cruises are to identify problems, but it is expected to identify minor issues not major propulsion problems that will cause many delays.

 

[SynixMan]

I mean the last time we designed a carrier was in the 60s. It wouldn’t surprise me if brain trust moved on. Sometimes we make hard shit look so commonplace we forget we’re the only country that does this.

 

[wlawr005]

My money says that GE is absolutely capable of manufacturing a bearing that works perfectly...they've proven that. I wouldn't doubt the fact the Navy probably wanted them to design a bearing with numerous tradeoffs on price, materials, and life cycle. Engineers are going to give you what you pay for..nothing more.

The sad fact is the Navy probably spent twice as much on half the product. I guarantee there's an engineer sitting somewhere going "I told you so"

 

[IKE]

My money says that GE is absolutely capable of manufacturing a bearing that works perfectly...they've proven that. I wouldn't doubt the fact the Navy probably wanted them to design a bearing with numerous tradeoffs on price, materials, and life cycle. Engineers are going to give you what you pay for..nothing more.

The sad fact is the Navy probably spent twice as much on half the product. I guarantee there's an engineer sitting somewhere going "I told you so"

Eh. From what I've seen at LM, it goes both ways. The acquisition behemoth seems to favor companies better at lobbying and contract negotiations than engineering. (I speak only from my experience with software types)

 

[nittany03]

Eh. From what I've seen at LM, it goes both ways. The acquisition behemoth seems to favor companies better at lobbying and contract negotiations than engineering. (I speak only from my experience with software types)

Well, that certainly explains JMPS . . . and NRRM . . . and fuck it, just about every piece of DoD software out there.

 

[Brett327]

DoD software

Hey, NAVFIT98 was clearly 20+ years ahead of its time. It's still relevant!