N700 Broken Gearbox Stops Shinkansen

[bill937ca]

This appeared on another forum yesterday, but its important enough to share.  And don't miss the photo sidebar on the final 500-series Nozomi.

 

http://mdn.mainichi.jp/mdnnews/news/20100304p2a00m0na013000c.html

[CaptOblivious]

Well, now we have an excuse to install smoke-generators in our model shinkansen!

[bikkuri bahn]

Interesting picture, you can see the exposed area is the upper portion of the housing, probably why some oil remained within.  I wonder what caused the fracture.

[westfalen]

They don't make Shinkansen like they used to.

 

I was surprised at the smallish diameter of wheel compared to the hand in front of it, at full speed the wheel and gear would be turning at rather high RPM.

[Guest ___]

Well, anything that is mechanical in nature is subject to a component or system failure, so there is no reason anything made in Japan (or Germany) would be any different.

[westfalen]

Well, anything that is mechanical in nature is subject to a component or system failure, so there is no reason anything made in Japan (or Germany) would be any different.

I guess the ICE trains have been having their share of troubles recently too.

[KenS]

Well, anything that is mechanical in nature is subject to a component or system failure, so there is no reason anything made in Japan (or Germany) would be any different.

 

Generally a failure like this occurs due to either poor design (metal too thin, etc.), poor manufacturing quality control (design not followed or flawed casting/machining) or poor maintenance (too little or too old lubricant, stress fractures not detected until they cause a failure, etc). While you can never eliminate random chance failures (e.g., a rock kicked up hitting a particularly weak point in a way nobody anticipated), where Japan's trains have always excelled was in good design, QA and maintenance.

 

The interesting question that comes from this incident is: was this a random event, or has there been some systemic failure in design, manufacturing or maintenance of this model that made this part a failure waiting to happen?

 

Unless it starts to happen on multiple trains it probably is just random chance, but with a relatively new model, the JR execs are probably having some sleepless nights worrying about the alternative.

[bikkuri bahn]

Reading some more recent articles, JR West is saying the possibility is high that a portion of the gear or other component inside the housing broke off and pierced the housing.  Other pictures have been released, showing a greater extent of damage, including a substantial 55cm long crack:

 

http://osaka.yomiuri.co.jp/zoom/20100304-OYO9I00738.htm