Rope Guide

Rope types

Synthetic rope (especially nylon) can be very slippery and may not work with frictions, it also requires you tie bulletproof knots which can be helpful for beginners but also frustrating. They also have a high burn rate on skin.

• Twisted Nylon 6mm 223-372 lbs. 
• Braided Nylon 6mm 198-331 lbs working load, 1325 tensile strength

Synthetic blend rope: POSH and Hempx these have more ‘tooth’ to them and keep knots and frictions nicely, slightly higher burn than natural fiber but overall ideal.

Jute -lighter, more tooth, lower tensile strength

Hemp- “hay smell” heavier, softer, moderately stronger.

Any of these are okay for accessory up lines.

in boating they use a x12 safe working load, in theatrical rigging they use a x10 safety factor. Meaning if you have a 100lb bottom you would want a working load of 1000lbs. natural fibers aren’t generally rated for more than 1000lbs making it just barely inside the recommended safety factor for very small bottoms

With all the hybrid and new synthetics there’s no reason to not use synthetic for your primary uplines besides tradition.

If you plan on doing drop lifting, inversions, spinning, flips, climbing on top of your bottom or any other “circus” rope use synthetic or the ghost of Tornus will come haunt you.

In particular issues with natural fibers include:

• You can’t safely do Shock loading (drop lifting, dynamic movement or other ‘circus’ rope).
• Natural ropes don’t like water, it causes the fibers to swell and shrink, making it less than ideal for outdoor rigging
• If natural fiber isn’t well maintained the rope can be significantly weakened (regular oil/wax conditioning and inspections for twists)
• Because natural fibers aren’t generally rated for more than 1000lbs making it just barely inside the recommended safety factor for very small bottoms.

Natural fiber uplines are fine for accessory lines (arms, ankles etc). or static ties

Rope only to be used in groundwork/ accessory body harnesses:

All of these are rated for 100lbs or less.

• Manila
• Sisel, the stuff you use on cat scatching posts…itchy and weak
• Coconut -think sisel but even scratchier and weaker
• Bamboo -super soft antimicrobial making it well suited for crotch rope, has a lot of stretch making it not suitable for uplines.
• Cotton- soft, cheap, looks nice but not rated for much weight beyond a clothesline.

The working load limit tells you the maximum amount of weight the rope should support at any time.  

• Polyester: Synthetic material that is UV-resistant, abrasion-resistant and maintains its strength when wet. Usually pre-stretched. Good choice for general purpose rope. 
• Polypropylene: Lightweight synthetic material that is resistant to mold, mildew and many chemicals. Floats in water. Has low resistance to UV rays and abrasion.  
• Nylon: Synthetic material that is both flexible and strong. UV-resistant and abrasion-resistant. Weakens in water and does not float. 
• Kevlar: Extremely strong synthetic material that is resistant to fire, extreme temperatures, stretch, water and chemicals. Has low UV resistance, so it is often covered with polyester. 
• Sisal: A natural fiber used for making twine, paper, cloth, carpets and more. Sustainable and biodegradable. Low water resistance and abrasion resistance. Prone to mildew. 
• Manila: A natural fiber that is very stretch-resistant and holds knots well. Sustainable and biodegradable. Like sisal, it has low water and abrasion resistance and can be prone to mildew. 
• Coir: A natural fiber made from coconut husks. Sustainable and biodegradable. Used in many gardening applications. 

Ways you can make rigging safer

• Use synthetic uplines
• Avoid rope on the back of the upper arms (TKs and strappadoes in particular)
• Practice harnesses on the ground before attempting suspension.
• Always use a mat or padding below the bottom especially when doing inversions.
• Tie closer to the ground

When to retire your Rope

1. Broken or cut fibers
2. Variations in size or roundness of strands
3. Discoloration or rotting
4. Abnormal wear
5. Powdered fiber between strands
6. Exposure to extreme tempatures (20ºF to 180ºF for natural fibers)
7. prolonged UV exposure of synthetic rope
8. prolonged exposure to water for natural fiber ropes

Upline technique

▪ Don’t lift on a single bight (i.e. use a double bight, A.K.A better bight or australian bight, instead to reduce repetitive stress on the bight). Carabiners and rappel rings also reduce friction stress on the bight.

• Never use run one rope through two hard points. this is known as the American Death triangle, the rope is actually twice as weak when run though two points. Alway only run the rope to one point, you can connect multiple uplines using a ring or plate to spread the load between two points.

Resources

https://www.boatsafe.com/rope-breaking-strength/

https://www.ravenox.com/pages/rope-tensile-strength

https://www.cdc.gov/niosh/docs/2004-101/chklists/r1n61s~1.htm

https://crash-restraint.com/ties/2