Friday, April 26, 2019

Sometimes change is good; other times it is not





















Here are three cases where a change was bad.

I wrote an article for the September 1995 issue of Claims magazine titled How to Investigate Corrosion Damage to Goods Stored, Shipped. One case I briefly discussed involved coils of steel wire which were wrapped in a laminate of plastic and paper treated with a vapor phase inhibitor. Right after their purchasing department changed packaging suppliers a customer rejecting an entire shipment of wire. When the new supplier had asked what they wanted to protect, purchasing told them it was steel wire. They omitted a crucial detail – that it was bronze plated wire for use in tires. The surface was plated so it would properly adhere to rubber. The inhibitor they got was intended only for steel (not copper), and corroded the plating an ugly blue.      

When Microsoft introduced Office 2007 they changed their default for saving PowerPoint files from type .ppt to a new type .pptx. We were using my laptop computer and projector for meetings of Capital Club Toastmasters, but it had an older version of Office. Very soon we ran into their new filetype. At the last minute one of our speakers had to figure out how to instead connect her laptop to my projector. Then I had to find and  download their PowerPoint Viewer software to cope with those .pptx files.   

On April 9, 2019 there was an article at Computerworld in Shark Tank titled Grease is the word. It described a case from back in the early 1970’s where the card reader on a mainframe computer was causing the system to repeatedly crash. Support technicians sent to handle the situation were baffled. Finally the manufacturer sent their design engineer, who arrived on a Friday afternoon. On Monday morning employees arrived to find the reader disassembled, a high voltage probe on an oscilloscope attached to the ground wire, and the engineer lying on the floor laughing hysterically. Eventually he calmed down, and told them what caused the problem. Bearings on the roller shafts of the card transport mechanism were supposed to be lubricated with a special conductive grease. Instead regular nonconductive grease had accidentally been used. Static electricity charges built up as cards were being read, until a high-voltage spark discharged them. The card reader was behaving like a Van de Graff generator. It was replaced by one with the proper lubricant. Electric arcing is a common enough problem with bearings that it is discussed on pages 16 and 17 of the Torrington Company Bearing Failure Prevention Guide.
   
The Currier and Ives image of A Changed Man came from Wikimedia Commons.

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