American Towman is billed as "Towing’s premier magazine," and they’ve covered the industry for decades, primarily focusing on emergency road service. Here their Field Editor Terry Abejuela provides a simple, easy-to-grasp demonstration of different configurations, how they work and what they do:
If any of you are interested in pulleys, sound off, and I can make a video showing you how I use them in my photo studio to make tasks easier.
via Core77
A Demonstration of Pulley Systems for Easier Lifting