in praise of an oily rag

Once upon a time, when steam engines were powering explosive economic growth and the men who operated such machines became one of the first blue-collar jobs to actually be considered honorable, despite the fact thaat most of them were filthy.  Part of this was due to a well-deserved fear of steam engines, since boilers were blowing up and killing people on a fairly regular basis, so the men who tamed and made safe such powerful engines "must be" accomplished or educated in some fashion.  The possibility that such men were merely mad as hatters was probably an unpalatable notion.

 Now these men were frequently seen holding an oily rag in one hand, and an oil can in the other.  This was because, in the early days of mechanization, sealed bearings had not yet been invented, so bearings required regular oiling to refresh their lubricant.  The oily rag was for wiping grime from polished surfaces, not for aesthetic reasons, but to keep sealing or bearing surfaces clean so that they wear out slower.

 In general, when working with heavy iron and steel machinery, one is always either on the lookout for, or doing direct battle with, rust.  We can't simply make all the machinery out of non-rusting steels for multiple reasons.  Cost is certainly a factor, but also cast iron has desirable properties which "stainless" alloys do not, and where hardened surfaces are required, stainless alloys simply are not suitable.  So every surface surrounding a turn-of-the-century engineer was something which could rust.  So if it wasn't painted, it had to be kept oily, not only to lubricate it, but to prevent rust.

 This is why the engineer or mechanic always seems to be wiping his hands on a dirty rag.  "Dirty" is relative, and quite often one finds oneself wiping something that should be kept oily.  One literally needs an oily rag 10X or maybe even 100X more often than a clean one.  Hell, I have been known to put oil on a clean rag for this reason.

 Although steam engines and their operating engineers went away, people who work with large machines still tend to keep an oily rag handy for the same reasons.  So machinists in a few small metal-working shops can still be seen with an oily rag in one hand, not only keeping their machine clean and watching its operation, but also listening to it attentively, since a slight change in sound can often predict a machine or part failure long before it happens.

 However, modern sophisticated machines with active lubrication systems and sealed or protected bearing surfaces are now being made from super-alloys which are both strong, hardenable, and rust-resistant.  And there are literally acoustic failure detection systems which can listen in place of the experienced machinist.

 Mean-Time-Between-Failure numbers - for good quality equipment - have gradually become enormous.

 And that means that slowly, the sight of the experienced old engineer / mechanic with the oily rag in one hand, is rapidly disappearing from this world.  Just another interesting change I have witnessed in my time so far.