The following took place during one section of a pre-purchase survey.
On the mainmast, the cap shroud plates at the masthead provided some interest as they were showing a form of corrosion I had not come across before. This was duly noted within the report, but it was the un-written hypothetical conclusion I could not disclose to the client. It was, in my opinion, a result of heat. How does a mast get hot one asks? Well, this particular rig had gone through a hurricane called Irma. If you are unsure who Irma was, let us put a figure on it that will help. Wind speed was recorded at 220mph.
The rig had been replaced only one year before. Chainplates had been already been changed, the stack pack was new, sails where new. The rig itself should not present any issues.
Does wind equate to heat? Yes but No; not really. There is a debate about harmonics within the rig but thats for another post.
The stress applied to the rig could have produced stress, bend a piece of metal long enough heat is generated. The more I pondered over the reason why the less lucid my thoughts became. It could be possible, as the masts did not fail nor did the rig, but surely at that wind speed, some part must have been under great duress.
Conclusion - a metrologist would be required to find the truth.
The experts - part II
I attended a seminar about rig surveying this year. The host asked for photographs of some of our experiences, and I supplied the photo of the plate. It had a lot of attention but received little answer to how it would or could occur, the best response was a lightning strike which indeed would have produced a lot of heat, but other damage would have been evident to which there was none. The next answer was the metal had started to change its molecular structure. Now, this piqued my interest, as stainless steel can change as it loses its properties and would make a better sense of the sighted evidence.
The kettle conundrum
Today though brought me a kettle. Odd you may say that this would be appealing to a surveyor, but funny how things just happen.
The kettle itself was producing rusty water. It is a stove topped kettle made of stainless steel, the bottom section has been pressed onto the top section making a lip both on the inside and out. As I peered into the gloom of the kettle to see, a familiar pattern appeared before my eyes. The kettle had started to break down and indeed rust on the thin edge join with a bloom of colour within the metal itself, just like the mast plate.
Oh my, I said. Now that is a conundrum.
The only common denominator here is heat and stainless steel, but compare the photos and judge for your self. My personal opinion, the stainless steel is of poor quality and the application of heat has changed the molecular structure of the metal. It still does not answer why the mast plate reacted the same.
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