Tag: fracture mechanics

Technology failures are inevitable. The trick is to keep failures to a minimum and to keep failures in the “mostly harmless” category. Certain types of equipment can fail and the failure does not result in consequences that are too serious, while other types of equipment failures can make a mess of things almost right away. Ship’s steering gear undoubtedly belongs in the latter category, and, therefore, steering gear normally gets special attention in its design and construction. In our office we have had a spate of steering gear failure investigations lately and very interestingly they all seem to have different causes.

 

 

 

 

 

 

 

 

 

This is just a short list of recent steering gear failures that we were involved in:

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There is a Cold War (remember, that was before 1989) engineering joke that goes as follows:

 

The Russians had built a brand new huge airplane, and it was the pride of Russia, but they had a continuous problem with fatigue fracturing at the wing to fuselage connection.

 

They tried everything and it just kept fracturing. One day there was a goodwill tour of Americans that came to Russia and one of the tour members was a Boeing engineer.

 

One of the Russian aerospace engineers discovered this and during a quiet moment approached the Boeing engineer to see if he had any suggestions on the fracturing problem.

 

The Boeing engineer quickly came up with a solution. He said: “just drill tiny evenly spaced little holes right along the path where the fracture appears and the problem will go away.”

 

The Russian thought he was kidding, but they were desperate and decided to try it. Surprisingly it worked, the wing never fractured at the wing root again. Years later the Russian met the Boeing engineer again, and asked how he came up with that idea. The Boeing engineer told him it was easy, he just made the wing look like the perforations in Russian toilet paper, since that never tore at the perforations either.

 

But is there a kernel of truth in the joke?

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