The term “rigging” in tree work refers to the practice of dismantling trees using ropes, pulleys and blocks. This is one of the most common ways our tree workers take care of overgrown limbs and manage tree growth. Rigging presents special hazards, including the risk of struck-by’s and tree failure, so proper precautions should be taken to avoid injuries.

Before Work Begins

Before rigging begins, arborists should inspect the integrity of trees to see if there are any visible defects that could affect work. If it is determined that the tree poses a risk of failure due to the forces of the rigging design then an alternate means should be sought. Additionally, all tree workers need to be properly trained to estimate the forces in a potential rigging load. Working load limits do apply, and all system components should comply.

Rigging Points

As an arborist, it is your duty to assess the structural integrity of all rigging points. Keep in mind, the rigging plan and tree shall be considered relative to the forces applied to any part of the tree – this includes branch attachments and anchoring roots – before a rigging point is selected. It is important to know the limitations of your rigging systems and its components. Remember, the rigging line should be the weakest part of your rigging system. Ensure that the greatest possible force (this includes all potential shock loads) are less than the strength of your rigging line. Additionally, minimize the number of connecting links for connecting components where possible.

Rigging Equipment

Make sure that all equipment being used is designed specifically for rigging operations and labeled as such, as it can be easy to confuse with other tree working equipment. Before beginning work, ensure you have chosen the right equipment designed for your specific rigging load. It’s important to keep in mind that if your rigging line has been used before it maybe be weaker, meaning it can break at less than the original breaking strength. In the event that rigging equipment becomes damaged, it should be removed from service to prevent injury.

Tips for Staying Safe

To prepare for jobs that involve rigging, there are some steps you can take to better understand the process:

• Work with your general foreman to learn how to estimate the weight of the tree you work on
• Review and understand all of the components and techniques in rigging
• Learn how to use lowering devices and avoid snubbing pieces off
• Practice rigging on smaller pieces

Next time you’re on a job that requires rigging, keep the above considerations in mind. By estimating rigging forces and following proper technique, you can avoid struck-by’s and rigging line failures.