My first wife, Teryl, had an uncle, whose name I forget, but who lived in the Baltimore area if I remember correctly. I do remember what he did for a living. He wrote books. He wrote training manuals for the military services.
I was a 2nd Lieutenant, US Army, at the time. My occupational specialty was Engineer Equipment Maintenance Officer. My job was not to torque bolts, replace parts, or make adjustments, but to insure that such actions were taken properly and equipment kept running and available for use. Teryl’s uncle wrote the maintenance manuals which described care and maintenance necessary to keep such equipment operating.
In military training I’d been taught that training manuals were written at sixth grade level. They included lots of pictures and illustrations with ample simple written directions. Teryl’s uncle took written material from engineers who designed and built dozers, cranes, generators, and boats and turned that technical material into simple language nearly everyone could understand.
In Vietnam I spent most of my time in an office working with depot stockage levels of spare parts for engineer equipment. At one time we supported up to 350 D7E Caterpillar dozers, fifty each 20 ton American Hoist and Derrick rough terrain cranes, numerous rough terrain fork lift trucks and innumerable generators of all sizes. A lot of equipment, maintained by a lot of maintenance personnel at various levels of support activity.
On occasion I was sent out as part of inspection teams to battalion size units which had whole shops dedicated to various types of equipment. One of my first stops in engineer equipment shops was the library of training manuals. Were they available to mechanics? Were they complete with books for each piece of equipment the shop supported? Most importantly, were they grubby, filled with greasy fingerprints. Dirty books indicated how much they were used by mechanics doing the actual work.