Long highlines are not a scaled-up version of the 30-meter lines most people learn on. The physics change, the rigging changes, the logistics change, and the mental game changes. If you've been walking shorter lines and you're curious what big-line culture is about, here's an honest look at what makes these projects different.

What "Long" Actually Means

There's no official threshold, but in practical terms the community generally treats anything over 200 meters as a long line, and lines above 500 meters as a big project. The current world-record spans are measured in kilometers. At those lengths, you're dealing with forces, sag profiles, and logistical challenges that simply don't exist at shorter distances.

The webbing alone becomes a significant engineering consideration. A 600-meter line in 20mm Spider Silk MK5 weighs roughly 24 kilograms. Getting that — plus anchoring hardware, tensioning gear, and safety equipment — to a remote anchor point often requires multiple people and serious hiking. This is before you've started rigging.

Getting the Line Across

On a 30-meter line, you can often throw a throw bag or walk around to the other anchor. On a 300-meter gap above a canyon, that's not an option. There are a few methods the community uses depending on terrain.

Tagline progression is the most common approach. You start with a lightweight cord — often 3mm or 4mm spectra or thin Dyneema — and either throw it, fly it, or hike it to the other side. Then you use that to pull progressively heavier lines across: 6mm, then 8mm, then eventually the main webbing. Each pull uses the previous cord as a messenger line. This works well when you can access both sides of the gap, even if the path is long.

Drones have become a legitimate tool over the past several years. A drone can carry a lightweight tagline across a gap where no path exists — overhangs, gaps with no anchor approach on one side, alpine features. Not everyone has access to a drone capable of carrying a meaningful load in wind, and regulatory considerations apply depending on where you're flying, but it's now a standard part of the long-line toolkit.

Rope guns — someone who leads climbs or rappels to place the line across — work for big wall or cliff-face setups where climbing access exists.

Anchor Systems at Big-Line Scale

The forces involved in a long line are substantial. A 500-meter line at reasonable tension puts 15–25 kN on each anchor point. Your rigging math needs to account for this from the start — working load limits, safety margins, and the behavior of each component under dynamic loading all matter differently when you're pulling hard with a come-along.

Equalized anchors that distribute load across multiple points are standard for big lines. The specific setup depends on what's available — rock horns, bolted anchors, trees — but the principle is consistent: no single point should carry the full load. Padding wherever webbing contacts rock is essential; even short lengths of webbing in contact with an edge can abrade catastrophically under repeated loading.

This is also where grog splicing matters. For long lines especially, the connection method at anchor points is important. A grog splice — a locked loop termination in Dyneema or similar high-tech cord — is significantly lighter than a metal shackle and can retain close to 100% of the cord's rated strength when done correctly. The technique takes practice and is typically taught within the community rather than from online tutorials alone.

The WLL Conversation

Working Load Limit is the number that matters in practice. MBS (Minimum Breaking Strength) tells you when hardware fails; WLL tells you how much you should actually put on it. For most slackline rigging, a 3:1 safety factor is the minimum — if your line will see 10 kN of tension, that component's MBS should be at least 30 kN. On long lines where tensioning forces climb higher, checking every component's WLL through the full system is not optional. A quicklink that's appropriate for a backup anchor on a 50-meter line might be the weakest point in a 600-meter rig pulling at 20 kN.

Why 20mm Webbing Exists

The shift from 25mm to 20mm wasn't aesthetic. On long lines in wind, 25mm webbing catches air. The main and backup lines start oscillating, slapping into each other, and in extreme cases the forces generated by that whipping can compromise the system. 20mm reduces the surface area catching wind by about 20%, which sounds modest but makes a real difference on a 500-meter line in any kind of cross-breeze. If you're rigging long lines, understanding why this change happened is part of the baseline knowledge.

For a full breakdown of the webbing types and hardware involved in long-line systems, the complete rigging guide covers the specifics. For finding people to actually learn this alongside, the community piece is the next read.

The Honest Caveat

Everything here is an introduction. The actual skill involved in rigging a long line — reading an anchor, calculating tension, recognizing when a tagline pull is going wrong, knowing when conditions aren't right to tension — comes from doing it alongside people who already know. No amount of reading substitutes for that. The community exists specifically to pass this knowledge along, and experienced riggers are generally generous about it.