The Aerial Friction Brake (AFB) functions like a friction control device and arborist block combined in one tool. This tool is based on Carroll Bassett's BMS Belay Spool, but adapted for tree work.
The AFB looks much like an arborist block, with an upper sheave for sling attachment and swinging sideplates for installing your rigging line after the AFB is attached to the tree. The rigging line is installed with 1-3 wraps, with two wraps being recommended for best function, and three wraps for loads that approach the working load limit of 1,000 lb. Three wraps will make the rope more difficult to pull back after loading.
The square bollard allows the user to easily control rigging loads from the tree. See the Aerial Friction Brake demonstrated by Niceguydave.
WLL 1,000 lb, rope capacity 1/2" - 3/4", weighs 3.35 lb.
|Min. Rope Capacity (inches / mm)||:||1/2” / 12.7mm|
|Max. Rope Capacity (inches / mm)||:||3/4” / 16mm|
|Working Load Limit||:||1,000 lb|
|Weight||:||3.3 lb / 1.5 kg|
The American National Standards Institute (ANSI) has released the ANSI Z133 safety requirements which apply to arboriculutral operations. Components of a rigging system must be used within their Working Load Limits.
The AFB is ANSI compliant when used within the manufacturer Working Load Limits.
A green log weight chart will aid in determining the loads in tree rigging.
The full ANSI Z133 safety requirements are available on our tree care standards page.