Installation, removal or other activity using lifting or suspension equipment and/or accessories to raise or support stages, trade fairs, performances or technical events. (UNE-CWA 15902 part 2).
Person with enough theoretical and practical knowledge as well as experience with such task, and aware of his knowledge limits, experience and competence. (UNE-CWA 15902 part 2).
Competent person who is capable to carry out rigging jobs. (UNE-CWA 15902 part 2).
Rigging’s team leader (UNE-CWA 15902 part 2).
Spin relation between the diameter of an object or a pulley (D) and the cable or string (d) which leans or goes through it.
It is the ratio of the breaking load and the partial force when the load acts (UNE-CWA 15902 Part 1). In other words, it is the relation between the minimum breaking load guaranteed by the manufacturer who has an equipment or an accessory and the maximum working load given by the manufacturer.
Minimum breaking load for any equipment, accessory or piece, guaranteed by the manufacturer.
Redundant security which takes action in case of a failure of the main system. The safety point must be tightened as much as possible for working with guarantee and avoiding that load might descend a long distance accumulating energy with the result of generating a greater load shock from the initial weight it had. More than 5-10 centimeters is not a safe option.
Working Limit Load W.L.L.
Maximum working load given by the manufacturer for an equipment. All equipment used for rigging and under the Machinery Directive must be marked with the W.L.L. among other data.
Uniform distributed loads (UDL) are loads distributed throughout a vain with the same value and weight along it. For example, lights distributed throughout a truss.
UDL load in one side of the vain is called concentrated load and is calculated as a Center Punctual Load (CPL) applied in the center of its position.
Fixed point loads
Loads that are located in one point and weigh 100kg or more, for example a moving head.
Loads applied on a part of an overhung truss with a single support (electrical chain hoist, truss leg) on one side.
They are loads that we do not control and are acting on our trusses. These loads must take into consideration, for example meteorological factors such as rain, snow or especially wind.