CLUTCH Technical Content
By CMC

CLUTCH Efficiency at the Head of a Mechanical Advantage System

Placing a CLUTCH at the head of a mechanical advantage system enables efficient hauling via the integrated rotating sheave (NFPA G-rated Pulley) while allowing immediate lowering of the load without system modification.


WARNINGS

 

  • Fully read and understand the CLUTCH technical manual before applying the following techniques.
  • Mastering these techniques requires training.
  • Consult a professional before attempting to perform these techniques on your own.

TEST METHOD

A 100kg test mass was raised with several rigging configurations placing different devices at the head of the system:

 

  • CMC CLUTCHTM
  • CMC MPDTM
  • Bobbin Style Descent Device
  • CMC HD4 Pulley
  • CMC Proseries® Carabiner

 

The test rope was CMC G-11TM Lifeline.
For the 3:1 system, a CMC PMP Swivel Pulley was utilized.

The force required to raise the test mass at a constant speed was recorded. Due to variables that are difficult to reproduce, the data is given for information only.

Efficiency (EFF) is calculated by dividing the theoretical force required to raise the load by the measured force required.


SIMPLE DIRECTIONAL AT THE ANCHOR (1:1 THEORETICAL EFFICIENCY)

 

 

CLUTCH Simple Directional at Anchor

 

 

SIMPLE DIRECTIONAL AT THE LOAD (2:1 THEORETICAL EFFICIENCY)

 

 

CLUTCH Simple Directional at Load

 

 

SIMPLE HAUL SYSTEM (3:1 THEORETICAL EFFICIENCY)

 

 

CLUTCH Simple Haul System