Purchasing Acrobatic Lunge (Longe Lines) - How to get started

Longes or Lunge lines or just lines for short, are more and more commonly used in the acro world

At many conventions or acro events these days you might find several or many longes, and they are more common in some communities too.

Interestingly though, there is relatively little information to be found about it online.

And we know this as we decided to purchase a proper set of lines so that we can set it up where and when we need to.

It's also interesting that again my past career of being an engineer actually comes quite in handy for acro here.

Whilst I don't have especially much knowledge about ropes and climbing or knots necessarily, I do know a fair bit about design, manufacturing, testing and safety rating of equipment.

Which I think is a pretty important aspect of this stuff, and maybe many people who are using and setting up this equipment aren't as aware about as they should be.

So I thought it would be a good idea to share some of this knowledge and information, in case it comes in handy for others.

Plus to just help if people are wanting to set up their own longes at home or in training spaces, how to go about it, what equipment to buy, and hopefully how to do it safely.

And just a note before I get into all of that, I have limited or minimal experience in physically rigging longes up so far, but that will change soon as I will be rigging our lines in the future.

So, lets start with equipment, what to buy, and how to know if it's suitable and safe.

For your typical partner acrobatics longe set up, it will look something like the following images:

The components involved are typically the following:

• One longe belt (harness)

• Two short slings

• Two swivels

• One static rope cut into two different lengths

• One single pulley

• One double pulley

• Two or more additional slings for attaching pulleys

• Two or more carabiners for attaching pulleys and or for easy connection/release

• Weight for storage/release 

This is more or less the setup and components for the longe, obviously it can vary in different ways of not having swivels, attaching pulleys in different ways and replacing slings with small ropes etc.

But this gives us a good starting point to work from, and to know what you need to get if you intend to make your own longe.

Here's a few more specific important points about the equipment...

1. Make sure to use static rope

Climbing or comercially available ropes typically fall into 3 categories, static, semi-static and dynamic.

Dynamic means that the rope stretches under load in some cases up to as much as 40% of it's length, and will stretch significantly under sudden force or load.

Static means the rope has little to no stretch under load, typicaly less than 5% of it's length and will have also a limited amount of stretch under sudden force or load.

And Semi-static is somewhere between the two, where there is some stretch, but not as much as dynamic ropes.

The reason for needing static rope is that if you use dynamic rope the stretch or elongation of the rope under load means that when a flyer is falling in acro, the rope will stretch and even if you pull and resist they may still hit the floor because of the rope lengthening and stretching.

Of course there is even more to consider with ropes such as diameter, material, and more, but suffice to say checking the safety rating in terms of working load limit and the stretch/elongation are the most important factors to check.

2. Check the safety ratings and working load limits of the pulleys, swivels, carrabiners, rope, slings and harness.

Essentially any component that is bearing the force and load in the setup, which is pretty much everything.

The safety ratings of most equipment available is usually displayed or referred to in kN. Kilo Newtons a.k.a. 1000Newtons which is essentially 100kg of weight.

This means if a piece of equipment is rated to 14kN it can support 1400kg of weight. That's about 20-30 flyers.

However, it's not so simple as that, because that only applies to static loading.

When a 50kg flyer is thrown dynamically a couple of meters up in the air and falls and has to be caught in a sudden stop on the lines. That will generate much more force than just 50kg's.

It can multiply the weight or load by many times, as much as 5-10 or even more times the weight.

So in a worst case scenario for example a 70kg flyer falling dynamically could generate up to 10kN of force in very extreme cases.

The next thing to keep in mind with these safety ratings is that often you will find two ratings, a breaking strength rating, and a working load rating.

The breaking strength means the force or load at which the component will completely fail and break/buckle (which hopefully we never reach on any equipment or it's potentially a big problem).

The working load is the safe rating at which the equipment can continually and repeatedly operate without suffering any issues.

This is a important one to note, because in acro if we are regularly when falling from acro tricks in the line generating 2 or 3kN of force for example, we want to choose equipment that has a higher working load limit than this, or over time the equipment may not function as well and have problems.

3. Check for safety certifications (here's the special engineering bit)

In engineering one way to ensure the manufacture and testing of equipment is safe and made to a controlled standard is to use safety standards.

These often look something like EN1238:2001 or ISO5974 and so on.

These safety standards are developed and maintained by safety standards organisations, the EN for example stands for European Norms.

And they outline the testing and manufacture requirements for a product to meet (for example a carabiner) to be allowed to give it a safety standard.

This means that carabiner had to undergo specific testing to prove it's working load limit and breaking load rating are accurate, and that it maintains certain testing in manufacturing to ensure the carabiners are consistently made to the same quality and standard.

Anyway, all of that is to say...

Don't buy equipment that doesn't have a proper safety standard marking on it.

If it doesnt have one of these it is potentially not reliable or accurate, of course it might be, but you're taking a risk that it could be made in a garage or warehouse somewhere trying to cut costs and make cheap equipment etc. (I think you get the idea).

4. Make sure you figure out the correct length of slings and ropes you need.

This will depend on several factors, like ceiling height, anchor points (where you will attach the pulleys to the ceiling), and how you want the setup at the belt end.

If the ceiling height is for example 7m high, and your anchor points are 4m apart, you will essentially have one piece of rope on the short side that needs to be minimum 14m long (7m + 7m) and one piece that needs to be minimum 18m long (7m + 4m + 7m).

But in reality you want much more than this so you have spare rope and extra space, so 20m would be a good amount on one end and 25m on the other end.

More or less, for most longes purchasing a 50m rope piece and then cutting it somewhere near the middle will probably be a good solution.

For the setup near the belt you need to consider where you want your metal components on the lines.

This is important because the metal components are dangerous and injurious if they hit flyer, base or spotter mid skill.

For example, if you set your metal swivels via slings 60cm away from the belt connection, they will be at the prime length to hit the flyers head more or less when there is some movement and slack on the lines.

So it's best to have your metal components very very close to the belt attachement, or very far away so impact injuries are less likely.

There is much more to consider when it then comes to longe setup and safety.

So stay tuned for the next part 2 where I'll dive a bit deeper on structural security, regular testing/checking of equipment, materials and abbrasion wear, and why I always ask for a test jump!

Catch you in the next one,

Cas