Using Hollow Blocks for Aerial Sling Rigging

If I could take back the first 5 years of my aerial performing life I would. I would take back the frustrating hours I spent trying to untie the incredibly difficult knots that became the ends of my aerial hammock. I loathed washing my fabric just because I knew I would have to fight them. I would take back the extra hours of "wiggle room" I gave myself before gigs to make sure I had enough time just to set the height that I wanted (because it was never perfect and I would have to tie/re-tie my knots to get it just right). 

Before you keep reading, I want to provide a disclaimer that I am not a certified rigger. However, I use this equipment and I trust it with my life and I also trust the company that  fabricates it. My knowledge comes from my own personal experience and absorbing as much information as possible over the past 8 years in terms of aerial rigging practices. I believe education in aerial safety and rigging is ever-evolving and we have to keep the conversation open to continue growth and progress in this industry.

Now that we got that out of the way...

I tell every aerialist I know about hollow blocks to tie their aerial hammock / sling. Why? I'll tell you why! But first, let's talk about a few common hammock / sling rigging techniques...



This is an absolute "no” for me and I think for most aerialists. If you are using carabiners to tie the end of your aerial hammock / yoga / sling...STOP. RIGHT. NOW. There's plenty of rigging information available now that will tell you why this is a bad idea. #1 first and foremost--the fabric tied this way will overload your carabiner. Vertical Art Dance has a great video explaining how this method can overload your equipment. 


While this method is acceptable and considered "safe," there are many reasons while I will never use an o-ring to tie my aerial hammock rigging ever again. Most of these reasons could apply to using a Rescue 8 as well. Here are just a few of my personal reasons, counting down to the most problematic.

Reason #3 - Heavy, Clunky, Loud

I like my apparatus to be soft & quiet. O-rings are bothersome to me because they can create loud, clanking noises if they are hitting other pieces of metal hardware. They also make the ends of my hammock heavy. I can't drop my fabric on the ground because the o-rings would hit, causing damage to the rings and to the floor most likely.

Reason #2 - Impossibly Tight Knots

It's been a month (or more) of use and it's time to wash your stinky fabric. You go to untie your knot and it takes 6 hands and 45 minutes of tugging, pulling, possibly even cutting your fabric. If you rig your own equipment, which I hope you do, you know exactly what I'm talking about! This is the opposite of problem #1, obviously.

Reason #1 - Knot Failure

This has never happened to me personally, but I have seen multiple aerialists through the internet and/or in real life (many of them who are "advanced" "experienced" "teachers" etc.) fail to tie off correctly to the o-ring. What happens when the knot is tied incorrectly? It slips! You do not want your hammock slipping right out from underneath you when you perform or teach! It's terrifying and it's dangerous. My first year in aerial I watched a performer's knot come untied and she was left with one side of her hammock dangling from the ceiling. I was new and completely confused because I thought maybe it was part of the act (I didn't know any better). Later on I learned what had actually happened and since then I have seen this happen as one of the most common rigging failures in the industry (as far as aerial hammock/sling rigging is concerned). 

So now that we have covered those two tragedies. Let me present to you, the unicorn of aerial hammock/sling rigging:


In 2016 I taught at the Vertical Art Dance Zion Aerial Arts Retreat and it was in that weekend I was bestowed my first ever pair of hollow blocks. They literally changed. my. life. Here's why:


Once you know how to wrap the hollow block onto your fabric & practice a few times, it becomes incredibly easy to do. I can install and remove my blocks in a matter of seconds--which makes laundering my fabrics a breeze! Hollow blocks also make it extremely quick and easy to adjust height. The hollow blocks do not have to be removed—while wrapped in the prusik, the entire hitch is held in one hand and can slide “up" or "down" the fabric to adjust the height. 


You don't need to know how to tie any fancy knots to use this equipment (this is not to say you shouldn’t know how to tie your own knots for rigging aerial). Based on which length of hollow block you buy you will need a 3 or 4-wrap prusik and a stopper knot at the end. Hollow blocks also meet a 10:1 safety factor for aerial rigging. They are extremely strong & heat resistant (chars at 950 degrees). The material they are made from will not melt from heat created by friction like traditional nylon or polyester. 

Watch this video from Vertical Art Dance on how to correctly tie your new hollow blocks:

Safety note: VAD frequently performs destructive testing on all of their equipment. When more test results become available from the hollow blocks I will make sure I update this blog. Visit to check out VAD's other rigging safety resource videos. This information is free and available to the aerial community. 


My soft hollow block rigging doesn't make noise against the other hardware on my apparatus. I can drop my fabric on the ground (after detaching from the metal hardware) and it doesn't make any noise or damage the equipment. I also really like the fact that my hollow blocks will not put wear and tear on my carabiners the way that a steel o-ring would over time. Similarly, because the hollow block is easy to remove/slide up and down, it prevents wear and tear on one specific area of the fabric. 


You can use hollow-blocks to make twin tail silks that are two different colors! This could be purely for aesthetic purposes but it's also useful as a teaching tool. (i.e. "grab your blue fabric and wrap behind your back. Now tie your foot with the green fabric")


$12.95 - $14.95 per hollow block through Vertical Art Dance AND if you use my code "hollyannjarvis" you get $10 off your entire order! That's a steal. For under $30 per hammock / sling set-up, you can have peace of mind and an amazing piece of equipment that will save you time and unnecessary frustration when it comes to rigging. You're welcome! :)

After you have purchased your new hollow blocks from VAD, tag us on Instagram and we will share your photo on our Instagram story! @verticalartdance @hollyannjarvis