The other day I was talking to one of my friends about non-destructive engine and component testing, and he told me about the tests they used to do in the locomotive industry.
It was certainly a surprise.
The conversation had been sparked by an email I sent about our shift to fluorescent MPI testing from the standard ultra-violet process (if you didn’t see that one, click here and read it), but Alan had experience of an earlier version known as “oil and whiting”.
If you haven’t come across oil and whiting before, it was used to test for cracks by using oil solvent for cleaning, then a chalk coating was added before finally hitting the tested part with a hammer to “encourage” the oil out of any cracks.
Not one of Bartech’s main engine or component testing tools!
And that wasn’t the only testing technique I heard of this week which has now been replaced with more reliable processes.
One of our engineers told me that when he worked at Paxman’s, they used to hang up the crankshafts and hit them with a hammer. If it rang like a bell, then it was theoretically free from cracks, yet if you got a really dull hollow sounding note then chances are it was cracked.
I can’t help thinking that “non-destructive” testing and hammers are somewhat mutually exclusive, but in that process, they were the main tool!
