Look at this rigging! “Is it Okay or Is It Not?”
I regularly receive pictures with the following question: ‘Is it Okay or is it Not?’ In some cases there is no doubt at all: the person that rigged that particular thing could make more money at the casino. The best one could say: “it did not come down, but is was absolutely Not Okay!”
Let’s use an analogy
Once you are involved in a traffic accident, you know something is Not Okay.
But when you are speeding you know it is Not Okay. However if you were not caught red handed and got away without an accident, that does not make it Okay.
In rigging we might not have the same amount of rules as in traffic, but certainly there are all kinds of legal borders, setting the safety of the environment for lifting activities.
However, in traffic there is not a lot of time to do a risk assessment. Most handling must be done instantly based upon the situation, driver skills and experience. In the rigging industry, there is (some) time to prepare the work. Depending on the situation, equipment and materials…. and of course based on the rigger skills and experience.
We have to know the load, before we even start lifting it. Trying to find out by using load cells is already too late. “We install 38 movers, 20 line-array cabinets, or 32 m² of LED-screen panels” is simply not enough! All these types of equipment have data on the self-weight and must be positioned in the right way above the stage. Even though it is not the most important issue for the lighting-, sound- or LED-technician, but for a lifting technician it is. We want to avoid that Newton’s grip on the show equipment turns out to be bigger than what we are providing in lifting capacity.
We want to be able to say that it is Okay with at least the margin that is set by the rules for our job. Therefore we must gather all data about the position and amounts of loads; we must do an (initial) rigging plan, do a risk assessment, do (preliminary) calculations and count in some ‘overcapacity’ to not have to disappoint people with small last minute changes. Afterwards make the rigging plot and reserve and order the equipment accordingly.
Once all the equipment is fixed to our hoists and trusses, we can check our calculations with load cells and see if it is within the capacity. If the read outs are significantly off, we should re-evaluate and check where the problem occurs. But at least, we know what was planned for in the first place and moreover, we know what we are doing.
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