Ontivity Resources

Currently, there are no industry standards or regulations regarding the qualification of components, compatibility, and use of wire mesh grips. Per the applicable standards utilized within the industry the use of a wire mesh grip with transmission line and hybrid fiber/power cables (i.e., cable), together comprise a lift system and ultimately a suspension system supported by the structure. Traditionally testing for the compatibility of components has been left to the discretion of the cable manufacturers and the wire mesh grip manufacturers. Therefore, NATE pulled together subject matter experts within the industry and published an advisory notice with best practices.

We would like to look at three key bullet points pulling information primarily from the advisory notice which closely coincides with a recently released industry publication. 

• VERIFY THE WEIGHT OF THE CABLE AND WEIGHT RATING OF THE WIRE MESH GRIP BEFORE HOISTING.

• SECURE THE WIRE MESH GRIP TO THE APPROPRIATE ANCHOR POINT UTILIZING APPROVED HARDWARE.

• ALWAYS USE A SECONDARY TO PREVENT DISLODGMENT.

VERIFY THE WEIGHT OF THE CABLE AND WEIGHT RATING OF THE WIRE MESH GRIP PRIOR TO HOISTING

Just the same as all chemicals have safety data sheets, coax and hybrid cables have spec sheets that detail their weight by foot among other things. As the competent person on site charged with the installation of these cables, it is imperative that we know and verify the total weight of the cable that is being lifted and that all components being used in the lifting system align with the rigging/construction plan and, more importantly, can withstand the forces induced. Failure to perform this critical step can and will most likely result in a failure that may lead to property damage and/or injury.

SECURE THE WIRE MESH GRIP TO THE APPROPRIATE ANCHOR POINT UTILIZING APPROVED HARDWARE.

In the most recent publication released by Crown, they state that wire mesh grips shall not be wrapped around components such as, but not limited to, a tower member, mount, ladder rung, or port hole rim. Wrapping the wire mesh grip around a member or edge reduces its stated maximum capacity. It is also stated that hardware used in permanent installs shall comply with ASME B30.26 there for quick links, angle adapters and beam clamps are prohibited. All anchor points must go back to the main structure or leg unless there is an engineered anchor or present. The industry has recently developed multiple products that can be used both on monopoles and lattice towers to better accommodate the permanent securement of wire mesh grips. If you need more information on these products, please reach out to the Safety Hotline, local FSA, or your immediate supervisor.

ALWAYS USE A SECONDARY TO PREVENT DISLODGEMENT UNTIL THE CABLE IS PROPERLY SECURED.

In alignment with our Falling/Flying Objects or Dropped Object Prevention program, the competent person on site must evaluate the site conditions and take necessary precautions to protect workers and the public from falling/flying objects. While hoisting cable with the use of a wire mesh grip, we must utilize a secondary lifting system that would prevent the accidental dislodgement of the cable in the event of a wire mesh grip failure. Ideally, this is accomplished with the use of a rated sling attached to the cable with the use of a prusik shackled to the load line. When doing this, we must ensure that the secondary doesn’t interfere with the synching capabilities of the wire mesh grip.

The use of wire mesh grips and installation of cables on communication structures continues to be a task that can be risky if not done properly. There have been numerous near-misses, property claims, and injuries tied to this specific task within our industry. But as always, our industry pulls together when faced with these types of issues and always prevails. At the end of the day, we must always refer to the manufacturer’s specifications when using wire mesh grips and lean on advisory notices, best practices, and our training. Today’s Safety Call was not intended to be an all-inclusive training on the do’s and do nots when it comes to the installation and use of wire mesh grips. That is why we have included two documents that provide additional guidance and recommend that those in which this topic applies to review. As always, we ask that you reach out to the Safety Hotline, your local FSA, or your immediate supervisor if you have any questions.

If you would like more information on this topic or any other safety-related topic, please reach out to the Ontivity safety team at safety@ontivity.com, and we will get you taken care of.