Last night at BOUND, we had a rope break incident. Fortunately, nobody got hurt. Wildties was finishing an astounding show, full of energy and dramatic transitions, when he decided to end on a single ankle suspension but as he began the lift, the rope snapped. Here’s exactly what happened.
Gorgone, his model, was on the floor and he connected a carabiner to the bight at the ankle tie. He took the line up to the suspension carabiner and then back through the ankle one, so as to act as a pulley and to reduce fiction to avoid sawing the rope. As Gorgone left the ground, one part of the doubled rope broke at the apex of the angle on the ankle carabiner. Fortunately, Riccardo Wildties being an experienced rigger, reacted instantly by grabbing the ropes and lowering her slowly back down. A less experienced performer might not have done so well and dropped her on her head with the risk of serious injury. This is where expertise counts; it ensures panic doesn’t take over. In too many riggers, confidence exceeds ability, and this is dangerous, especially when the shit hits the fan.
Whilst I was videoing the show, I was framing Gorgone too tightly to see the actual break. However, you can see how well he handled it and how gently she touched down when I publish the video later. If anyone has stills showing the break, please contact me.
Riccardo says the rope was due for retirement as it was well-used. It started as a 6.5mm 3-ply twisted jute but had stretched out to nearer 5mm. We examined the rope. The break was around 40-50cm from the end. In my opinion, it appears in very good condition and there is no visible wear on the bight (usually the first place to show damage) or elsewhere.
It’s hard to find data on the tensile strength of natural fibre rope. This is mainly because nature provides varying materials according the fibre type, weather, geography etc. and many factors like knots, age, fungal attack, wear and tear will all effect this. In general, it seems 6mm rope is about 50% stronger that 5mm. Thus, if, say, your 6mm is rated at 100kg, 5mm will only take 65kg. Of course, the rope is used at least doubled so the margin increases but we are working close to the limits. Jute is usually not as strong as hemp and much less than most synthetics. Bear in mind that most pros using 5mm are Japanese and thus have models of around 50kg. The average American adults weights are 88kg for a man and 75 kg for woman but many rope bottoms are above average weight. Gorgone is about 50kg and Nina around 42kg. There are very few 5mm jute ropes I would trust much over this weight in critical applications like a main suspension line. Hebari tested my Asanawa Tossa 5mm at 250kg but this is in ideal conditions, with that batch, on that day and so on. This is one of my stronger ropes so bear in mind loose laid versions like the standard Asanawa or typical Japanese rope are likely to take less load. I am going to experiment with some using my synthetic hemp for main lines as this is rated more like 350kg and is less prone to deterioration. Another strong alternative is reinforced jute, which I have also added to the range.
Another issue to consider is friction and wear. One should be very careful to minimise friction to avoid undue stress or sawing the rope, I will write more on this in due course. Waxing and oiling ropes helps mitigate this. It is for this reason I developed NaWaX, my rope treatment wax.
The skimping on rope replacements is false economy. Yes, it is expensive to keep renewing your ropes but if you run your rope into the ground, your rope bunny might follow with tragic consequences. So far, we have had no very serious consequences to rope breaks but if somebody takes a dive head down into the ground, it will be a different matter.
See ‘Avoiding rope breaks’ for an insight into this failure mode.