Mind your Prusik!


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The Prusik hitch has been around since 1931 when Dr. Karl Prusik created it while mountaineering in Austria. It is a hitch secured to a tight line and will slide when not weighted on a tight rope but jams solidly upon loading. It is recommended to use 2-3mm diameter less than that of the rope size and a prusik 35 cm length works best. 

In rigging the tower, most crews are using the material handling Rock Exotica Omni-Block Swivel® with a side plate. This side plate is a prusik-minded pulley (PMP) to prevent drop loads either live or equipment. Prusik-minded pulleys are designed with an extended side plate to prevent a prusik hitch from entering the sheave when using a capture progress system. There have been many studies and tests done on the prusik and this friction hitch rigged with a PMP is a progress capture capable of holding 1,000 to 2,500 lbs. depending on the rope size and prusik cord size. 


  1. Prusik must stay intact and snug when rope is hauling the load up.
  2. Monitor the rigging and assure the self-tending prusiks are well set up and working properly. 

It is recommended to have someone monitor the prusik use. Tower Safety along with AHS Rescue have worked together to create a video on how to use a prusik minding pulley (PMP). Watch it here

By Kathy Gill, Founder and CEO, Tower Safety & Instruction

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