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As to your example, I have a similar one. I worked in offshore drilling in West Africa. Our winches had proximity switches to assess the position and also to stop it before hitting the derrick. We had two winches, so 6 of these P+F proximity switches installed. One Sunday I get a call that one failed, when I get there I realise it's actually two and by the time I finished the call three had failed. All in, four failed on our ship that Sunday afternoon in sequence.
I didn't have four spares, so installed whatever I had in the warehouse and kept the machines running... come to my office thinking to write to the nearest ship to us (2 years newer) to pinch their stock thinking that since they have redundant proxes, they'll have enough for me to get up and running. Lo and behold, I already had an email from them saying that 8 of their 12 switches failed and they needed my stock to get back up and running.
Worst? Went to the workshop, wired the proximity switches and all of them were working but clearly did not work when in the derrick. We sent all of them to P+F in Germany and got told that these things don't like tropical weather and it's ikely the cause of the failure. Bear in mind that the proximity switches were installed nearly 2 years apart too.
it was one of the most stressful times I had but also pretty cool as I had them replaced without going into downtime.