Twin Tensioned Highline Anchor System

As rope rescue systems grow more advanced, so do our expectations for precision, safety, and minimal impact. When constructing a twin tensioned highline system, the reliability of your anchors — and how they manage load — becomes mission critical.

This article breaks down a field-tested twin highline anchor system built on removable bolt (RB) anchors, designed for use in a high-traffic climbing area with zero permanent impact, yet strong enough to support full rescue operations. We’ll also explore twin-system redundancy, load sharing, and the use of in-line dynamometers (like the Enforcer) to manage real-time force data.

Whether you’re working in technical rope rescue, wilderness access, or swiftwater environments, this is the kind of anchor design that allows for both control and adaptability in challenging terrain.

Anchor Type: Removable Bolt Anchors

The primary anchors in this system are ¾-inch PMI Removable Bolts, chosen for their high strength and environmental discretion.

Why RBs?

• Minimal environmental footprint (no hangers or hardware left behind)

• Rated for 22 kN (≈ 5,000 lbf) when loaded correctly

• Compatible with solid rock or 3000 PSI concrete

• Fully removable and reusable

• Holes can be patched with Quickcrete, dirt, or local stone dust for visual concealment

“While it’s not no trace due to the holes, it’s about as low-impact as it gets for high-load rescue anchors in public areas.”

Twin Anchor Load Sharing

This highline setup uses a twin anchor system, where two removable bolts on each side share the load equally through proper rigging.

Key Load-Sharing Features:

• Each anchor is independently equalized using static webbing or cordage

• Connected to a master point, distributing load between the two RBs

• If one anchor fails, the second remains fully capable of carrying the load

• All webbing is terminated with a water knot and a minimum 4-inch tail

Equalization ensures no single bolt sees the full system force — a crucial step in honoring the 22 kN rating of the RBs.

Monitoring Load with the Enforcer

In this system, a Rock Exotica Enforcer load cell is placed between anchor legs and the master point — giving rescuers real-time insight into how much force is on the line.

Enforcer Placement Options:

• Between one RB and the master point (to monitor individual bolt force)

• At the master point (to capture total system load)

• In-line on one of the tensioned highline ropes (used in this setup)

Benefits of Force Monitoring:

• Confirms balanced load sharing

• Helps avoid exceeding rated strengths

• Allows teams to adjust tension with precision

• Adds safety data to post-operation review

System Design and Environmental Considerations

The twin tensioned highline spans a swiftwater environment, with steep, granite-lined terrain on both banks. The rigging team strategically placed anchors:

• Higher than typical anchor points to allow for built-in sag

• Sag = less force on both ends of the highline

• RBs installed in solid granite, avoiding flakes, cracks, or shallow placements

• Drilled deep enough to accommodate removal, even with dust or impaction

• Anchors mirrored on the opposite bank, minus the Enforcer

Highline tension was balanced across a 600-foot rope — rigged independently on each end to preserve redundancy despite a shared rope body.

Tagline and Brake System Setup

This highline system includes an integrated tagline to manage patient movement and control, anchored independently using the same RB approach.

Tagline Features:

• Anchored with webbing and water knots

• Routed through a brake rack for smooth control

• Could be adapted to other devices like a Rig, ID, or twin Prusiks

• Operated with a backup belay and edge minder for safety

The key is flexibility — any reliable brake system can be used, as long as it’s properly anchored, tensioned, and controlled.

Single Rope, Redundant Connection Strategy

The 600-foot rope used for the highline system is a single continuous rope, but it is rigged with separate knots on each end, creating two independently tied anchor terminations.

Pros of This Approach:

• Faster to rig across long spans

• Minimizes mid-span transitions

• Easy to equalize with mirrored systems

Cons:

• Heavier rope = more sag and load

• Requires careful separation of terminations for true redundancy

Even though it’s one rope, it’s rigged to act like two systems, giving operational redundancy with cleaner transport.

End-of-Day Removal and Leave-No-Trace Finishing

Once the operation ends:

1. Each RB is tapped with a screwdriver to release the cam

2. Bolts are backed out and stowed

3. Holes are filled with dirt, rock dust, or quick-set mortar

4. The site is left almost invisible to hikers, climbers, or land managers

Summary: Twin Tensioned Highline Anchors with RBs

Building a twin tensioned highline system using removable bolts is one of the most effective ways to meet the demands of real rescue — without leaving a permanent mark on the landscape.

By using PMI RBs, load-sharing techniques, real-time monitoring with the Enforcer, and mirrored, independent terminations, this system is:

• Redundant

• Environmentally conscious

• Functionally advanced

• Fully removable

It allows teams to operate in climbing zones, public lands, and water-risk areas without compromising on safety — or leaving their gear behind.

Related RLA Resources

• Building Better Anchor Systems in Technical Rope Rescue

• Understanding the Forces of Rope Rescue Systems

• Anchors and Directionals in Twin Tension Rope Systems