Pulleys Single v Double Fixed v Swing

The Technical Rope Rescue world has lots of different Pulleys by lots of different manufactures, some single, double, fixed, swing cheek, swivel etc etc

A rule of thumb to follow would be if it’s a single pulley then you a single line of course, but I have seen a double pulley used with only a single line, which in the pictures below you can see introduces rope rub on the side plate which could fail the rope or fail the plate of the pulley.

Some single pulleys now allow for side by side use as in the picture on the far right.

Swing or Swivel pulleys are better to use if we think the pull of the lines are going to twist during hauling, this is where a fixed one would cause you issues that you would have to address once the lines loaded.

Larger Eyes on the pulleys take 2/3 Crabs or soft slings, greater flexibility again.