I stumbled across this magazine article series by accident and was so pleased with its content and comprehensive nature that thought I would pass this along to others in case you weren't aware of it.
As a semi-newbie to the hobby I wasn't active in 1995 to know about this magazine, let alone the series.
Model Railroading magazine ran the series from Jan 1995 to Jan 1996. It is available online for FREE at trainlife.com. It was written by Al Buchan, a former PRR track department employee.
Even though a fair amount of the photos and MOW practices described in the series are centered around the PRR, there is plenty of information about other roads as well.
All in all probably the best information available on MOW practices; an often overlooked part of the prototype. With so many MOW cars available in O scale, these articles teach you how to use them just like the prototype.
Enjoy!
Bob