Visit our new website at www.gaparboristsupply.com
One of the questions that we are asked frequently is which type of rope is best to use for Arborist work? Many possibilities exist depending on how the rope will be used. However, it is important to use a rope that is clearly identified by the manufacturer as suitable for tree climbing or rigging. Just because a rope has a suitable tensile strength doesn’t mean that it can stand up to the rigors of being used in a tree. Each rope is manufactured differently, and will perform best when used as the manufacturer intended. Ropes manufactured for tree rigging operations are typically made with a blend of materials, polypropelene-polyester, nylon-polyester, polyester-polyester, or some other combination. Rigging line is never a solid nylon line. A rope that is made for general purpose work will likely fail quickly when used for tree work; sometimes with disastrous results.
When selecting rigging ropes there are not as many options as with climbing lines. There are two basic options, single braid or double braid rigging lines. The single braid lines are less expensive than double braid lines and will hold up better than double braid lines when the tree is used as the friction device. If you are using wraps around a limb to lower sections, you are going to want a single braid 12 strand rigging rope. 12 strand rigging ropes such as Samson Arbor Plex, All Gear Forestry Pro, and Yale XTC-12 are all single braid arborist rigging ropes that will hold up well to abrasion against bark. One of the concerns with using the tree as the anchor point for rigging is that the friction is inconsistent compared to a Porta Wrap, Low Friction Rigging Rings, or another friction device such as an Ox Block or Stein lowering devices. 12 strand single braid can be used with rigging hardware, but you are losing the capacity to lower larger limbs by selecting this rope over other stronger ropes. Single braid lines typically have a tensile strength that is considerably lower than that of double braid lines, but because the 12 strand ropes have more elongation that double braid ropes they will be more forgiving if an inexperienced ground man doesn’t let the line run.
Another type of single braid rope is the 3 strand rope. 3 strand ropes are much less expensive than 12 strand or double braid rigging rope. 3 strand rope can be useful, especially when used with the continuous rope puller. The rope that we have found to work best with the rope puller is Samson Pro-Master. Other 3 strand ropes tend to be softer, and slip when engaged in the gear of the rope puller. Even other Samson brand ropes don’t work as well as Pro-Master when used in this system. A continuous rope puller can be used for hauling, tensioning rigging systems, or putting consistent tension on a tree to drop it in the proper direction. While 3 strand ropes are considerably less expensive than 12 strand ropes, they aren’t as durable as 12 strand when rigging naturally.
Double braid rigging ropes typically have a higher tensile strength, less stretch, and have better knot tying and handling characteristics than the single braid rigging lines. These ropes will be more expensive than single braid ropes, but if used properly they will outlast single braid ropes. The cover and the core of double braid ropes share the load Taking wraps on a branch will prematurely wear the cover. The common brand names are Samson Stable Braid, Husky by All Gear, and Yale’s Double Esterlon. The higher tensile strength allows you to lower larger sections of wood. The trick with rigging is to effectively manage tension and friction to safely lower limbs.
When choosing a rigging rope, it is important to remember that the rigging hardware should match the rope being used. A 4:1 bend ratio should be used, so a 1/2” rigging rope should have a 2” sheave on the block. If using wraps around a branch, a 2” branch should be used for a ½” rope. Around a Porta Wrap you can use a 3:1 bend ratio. Whichever type of rope you choose, the best way to optimize the life of the rope is to use it at a 10% safety factor, and then cut that in half. So for a double braid rope with a 20,000 lb. tensile strength, it will have a working load limit of 2,000 lbs., and then cut that in half for a working load of 1,000lbs. With this scenario, when pushing the limits of the rigging system you will have an added safety factor and are less likely to prematurely wear the rope. Additionally, the load may be much higher than the weight of the wood being rigged. Before performing any job, you need to inspect the components of your rigging system to make sure that they are in proper working order. Inspect the rope for abraded fibers, glazing, inconsistent diameter, or tears and cuts in the rope fiber. Rigging, like all arboricultural work, needs to be performed with safety for people and structures as the primary concern. Selecting the proper rope for the application, and inspecting the rope for integrity is one step for keeping crews safe on the job.