Working with a weight or strength imbalance

Posted on Thu, 11 July 2013

Both current and previous models, Nina and Jenis, are very slim and light. They also rig very well themselves. However, with the lightest of them, Nina, under 7st (around 40kg), they both almost invariably find they have models who are heavier. Jenis tells me the heaviest model she suspended was a guy of 17.5st (over 110kg). So, the challenges of this have been much in discussion and follow on from 'Tying heavier models'. In floor-work, try to avoid lifting. Where possible using rolling movements and pivot points. Think how you can roll a log or 'walk' a large appliance by tipping it and pivoting alternately from left to right corner as you swing the airborne side forward. To move a bound body to the floor, you can use your own body as a ramp upon which to slide them down. Always bear in mind that once you get beyond a balance point, the weight will suddenly become much harder to control. In these situations, it is wise to ensure you block any potential fall using your body of limbs.

It is always a question of working smart. Brains not brawn applies what ever your strength, weight or skill. Ever since the ancient Egyptians built the pyramids, and possibly before, we have used levers to minimise effort. Fortunately, there's no need for crowbars or the like as the human body has its own built in 'levers'. For example, pulling the upper torso will cause the body to pivot about the main contact point with the floor. A leg can be used as a lever. Of course, one should respect the limits of movement and flexibility and the laws of physics. The longer the 'lever' the greater the effect that will be exerted by a given force. Not a huge a mount of strength need be applied to create severe pain or even serious injury in a strappado position for this reason. Make sure you are not forcing any limb where it is not meant to go!

In suspension, the secret, where a weight or strength issue arises, is to use balance points to minimise the lift or leverage required. This is achieved by lowering the centre of gravity. For example, if one has a model standing with a suspension line over your ring or karabiner connected to the rear of a takate-kote, then try you try to lift the model, you will have to apply a load sufficient to counteract their weight as you are lifting directly over the centre of gravity. This is the load requiring the most strength and weight differential. Regardless of strength, you must be heavier than your model or you will be the only one to leave the ground! However, if you tie off the line with your model some way from the point directly below your suspension point, you ensure some slack when they return to centre. This means you can then push their torso off to one side and have more effective leverage to facilitate lifting the legs into suspension positions. Think how a wheel-barrow works to allow you to lift and move a heavy load with minimum effort. The principle is very similar.

Although friction is your friend when tying or when lowering. it is your enemy, with its ally gravity, when lifting as it makes a hard job harder. Despite all appearances, even the rope gods cannot overcome gravity, so anything you can do to reduce friction is all to the good. The greatest friction will be from rope on rope. Thus, if you are using a pulley system, by running the rope back from the suspension point to your harness and down again, you will get a lot of resistance from where the rope runs through the bight or under the inverted Y-connection. Running through a 'biner instead will make a massive difference as it creates much less resistance. You can make a small improvement at the overhead point by switching to a ring with a gentle radius, i.e. around 25mm/1". The sharper the turn the rope makes, the greater the friction and the more damaging to your rope.

It would be wise to have a read of the articles on rope breaks. Although, I don't see much likelihood of feather-weight riggers doing dynamic suspensions with models vastly heavier partners, it should be born in mind that appropriate rope should be used nevertheless. Whilst you can get away with 5mm jute with a tiny Japanese girl, 90kg/200lb of prime beefcake is another matter!

If you are new to suspension or heavier working loads, be aware that the greater the weight the harder it is. It is something I appreciate every time I work with even somebody of average weight. Lifts are more strenuous, it is harder to 'brake' the rope by tightening your grip, jams are more likely and knots can be much harder to release. It is also a lot harder to get out of trouble if things don't go right. I have had a rope jam but been able to support or lift Nina and still have a hand free to release it with barely a hiccup; with another 20kg or so and it might be a different story.

The physics and engineering in shibari are not a special case. The same laws apply as to the rest of the world. Be aware of at least the basics of these principals and it will make things a lot easier.