How do you take your anchors? Up? On the rocks? Dirty? With a twist? Shaken, not stirred? I prefer mine twisted, backed up, with a loop.
Excuse the puns, but as a 007 fan, I couldn’t resist. (Photo 1) This article will take a look at the minimum requirements for a base anchor in a stationary rope system (SRS) for climbing. Since climbing gear and techniques are changing with every new YouTube video, let’s discuss a few ingredients every sound base anchor should have.
Objective: To utilize an anchor that is effective, safe and understood by all.
1. Simple. Everyone on the crew, as well as anyone who may need to be on the crew (in the event of an emergency), should, at the very minimum, understand and be able to operate the anchor. This is easier said than done! At a minimum, the climber and his/her direct support (the ground crew) should understand how the anchor works. (Photo 2)
Lesson learned: Once while attending an aerial-rescue-training workshop, I witnessed a climber who, due to extenuating circumstances, found himself needing to be lowered out of a tree. The climber was suspended approximately 25 feet in the air on a stationary rope system utilizing a base anchor. The anchor was a mechanical device that, although well known to the instructors, was not at all familiar to others in attendance at the event. When the onlookers realized the climber needed to be brought down quickly, they immediately stepped toward the device to lower him. To their surprise, they couldn’t do it.
They could not lower the climber in need. The device was locked! The anchor had an emergency cam and, at some point earlier in the day, it had engaged and locked the device. No rope in, no rope out. Fortunately, a bucket truck was readily available and the climber was brought down without incident. This is actually the only aerial rescue I’ve ever been involved with, and yes, it happened during practice!
2. Accessible. (Photo 3) The working parts (device, attachment loops, rings, etc.) should be within reach of all crew members, including the short ones – sorry, vertically challenged friends.
3. Lowerable. (Photo 4) The anchor should have a rescue component. This could be elaborate, such as a belay device with 100 feet of rope behind it, or a simple midline loop and available lowering device. Just by adding this loop, the door is open to endless options for lowering an injured climber.
4. Clear. The anchor should be clear of brush dragging, rigging lines and cutting activities. You may be thinking, “OK, so we’re never using base anchors again!” Our company uses a 10-foot rule: No cutting by anyone other than the climber within 10 feet of the anchor. This includes pole saws and any extension cutting tool. Climbers also have the option to move the anchor to an adjacent tree or suitable structure away from these activities.
Lesson learned. About three years ago, a tree crew was manually taking down adjacent trees, one climber in tree A and a second climber in tree B. One of the climbers cut and sent down a large limb that landed next to the other climber’s tree – and next to his base anchor. An inexperienced ground worker started using a chain saw to cut up the downed limb and struck the base anchor of the other climber. The climbing line was damaged but not severed. This incident alone could be used to address a number of safety issues, but the end result was a “no-cut” policy established for within 10 feet of base anchors. I still keep the cut section of rope next to my desk as a reminder. (Photo 5)
A fellow climber and friend explained this much more simply a few years ago. Speaking about base anchors, he said, “If I see you cutting anything, anywhere near this, I’m coming down and I’m taking you out!” His name is Derek Martin, and he wasn’t kidding.
5. Keep flop factor to a minimum. Ensure all parts of your anchor align when loaded, unloaded and loaded again. Make sure carabiners will not side load. Make sure mechanical devices will not inadvertently unlock or release.
At our company, I require three things of a base anchor: a running bowline with Yosemite tie-off, an alpine butterfly loop above the bowline and a half twist around the trunk or base of the tree.
Explanation: First, this is a minimum requirement. Each climber at our company is free to build his/her own anchor to meet specific wants and needs, but this specific anchor is taught, explained and widely used. The bowline with Yosemite tie-off is a great knot and works well with multiple rope types and constructions. Also, using a knot to terminate the climbing line eliminates the need for additional hardware at the base of the tree. Note: The anchor should always be loaded “against the bight.” (Photos 6 & 7)
The alpine butterfly loop is for adding a rescue system without the need for a floating or “secret-weapon” anchor. A quick addition to the anchor would be to add a second loop just above or below the first. The second loop adds convenience to a rescue system. (Photos 8, 9 & 10)
The added twist is for minimizing flop factor, adding friction and creating slack for untying the termination knot. In a rescue situation, hanging your body weight or using a device to take the load of the climber will create enough slack to unwind the twist and untie the anchoring knot without the need for cutting a rope.
Please keep in mind, there are many factors that determine which anchor you choose. Your choice will largely depend on your gear and how much you want to spend. Other determining factors include the quality and training of your ground crew/support staff, as well as how many people at your company use this type of system. If you take nothing else from this article, remember this: Your base anchor must be effective, safe and understood by all! If it fails to meet just one of these requirements, move on.
Aaron Feather, CTSP and Certified Arborist, is safety and training director with Cumberland Valley Tree Service and Landscaping, an accredited, 21-year TCIA member company based in Chambersburg, Pennsylvania.
This article was loosely based on his presentation, “SRS Systems,” made during TCIA’s Virtual Summit ’21, which took place in January of this year. Click below to listen to an audio recording of that presentation.