Benefits of automated stage technology Statement: A stage director will then get aware of stage technology when it's not giving enough room to realize his/ her demands.
In 2000 the health authority in the Netherlands worked out a new regulation. The regulation states that manual rigging systems are only permissible when being a counterweight system with a maximum of 20 fly bars and a load of 75 kg each. This regulation became operative in 2007. Based on a generally accepted international regulation (heaving 23 kg), a whole county has been automated in a very short period of time. The theatre culture in the Netherlands is different to other counties. Theatre buildings are separated from the touring theatre companies. The socialistic concept behind it was to carry the arts to the people. This concept leaded to the demand of uniformity of the rigging system (e.g. everywhere the same fly bar interval). As the theatre companies start building up the scenery usually on performing day also other demands got more and more important: good organized logistics, easy offloading from the truck, light and easy to handle pieces of scenery, many fly bars, very quick and easy programming of the fly bar system and so on. The Netherlands are a small country, but with its nearly 17 million people, quite populated. The theatre culture there is distinctive, from the very little theatres to the big stadiums the country counts about 400 stages, wherefrom about 120 proscenium theatres with automated stage technology. As generally is known the Netherlands are a very economical orientated trading country. Therefore a quite important reason for keeping this touring theatre concept is that 12 travelling people of a theatre company are much more effective then 600 travelling people for audience. What also increases the efficiency is the fact that the touring productions are made for a big audience. Therefore, this concept is definitely very interesting for big countries as China, too. Coming from this empirical background this paper will take a look at the benefits of automated stage technology. Which effect does an automated system have on the possibilities within the arts and do all the safety factors automatically guarantee safer working conditions? PAGE 2
1. Health care As experienced theatre technicians will know, work with manual rigging systems with or without counterweight is hard physical stress. In 1991 the National Institute for Occupational Health and Safety (NIOSH) calculated the setting limits for lifting capacity as follows: RWL = LC * HM * VM * DM * AM * FM * CM Explanation of the abbreviations: RWL, the "Recommended Weight Limit" LC is the load constant we are looking for HM, the "Horizontal Multiplier" factor VM, the "Vertical Multiplier" factor DM, the "Distance Multiplier" factor FM, the "Frequency Multiplier" factor AM, the "Asymmetric Multiplier "factor: The twisting angle (A) of the body while lifting, measured in degrees. CM, the "Coupling Multiplier" factor The result of the NIOSH lifting equation is a maximum load constant of 23 kg, but only under perfect conditions. In consequence of the NIOSH lifting equation, the Netherlands had a new regulation in 2000. Due to this fact, nearly all the manual stage technology in the Netherlands needed to be automated. Since 2007 all Dutch theatres affected, have automated stage systems. Nearly 6.000 fly bars have been replaced, nearly all of them developed and produced in the Netherlands. Manual theatrical rigging system PAGE 3
2. Functionality to provide best on artistic demands A maximum of flexibility can be provided by several issues. 2.1 Mechanical installation and building Usual grid decks Clean grid decks With well-planned and engineered clean grid decks (as are built in the Netherlands) placement of electrical point or chain hoists on or above grid deck is possible at any place. Due to this, exact placement of scenery almost everywhere on stage becomes possible. At least, work that has to be done at grid decks got much safer due to this new design. PAGE 4
2.2 Software The nearly endless possibilities of programming creative movements of the rigging system and - if integrated - other stage technology, like orchestra lifts or stage doors, open new dimensions. "Elf minuten" Noord Nederlands Toneel, the Netherlands PAGE 5
2.3 Method of programming the software Very often communication and understanding between the arts and theatre technicians is quite difficult. A software thinking from the artistic and art developing point of view is thus extremely helpful. To teach a technician to stay conscious about these differences will also help very much solving problems on stage. Example of stage technology control software PAGE 6
3. Safety During development and engineering there are safety factors the manufacturer has to calculate and engineer with. After the handover the owner is responsible for the safety of the installation. How can he provide this? At least, usage and operation on stage have to be done in a safe way. What are the rules to provide safe working conditions for all people involved? 3.1 Machinery engineering In Europe all machines have to be built as defined in the EC machinery directive: the engineering of a machine must be correspondent to the risk assessment of the machine. Engineering of the machinery First, all risks have to be detected. After that, the risks must be assessed. A risk graph will help to define the measures for each risk that have to be taken: Measure of damage Dead Occurrence probability Likely Possible Unlikely Lost finger e.g. Reversible injury (needs medical help) Reversible injury (needs first aid) According to the risk graph, measures must be taken in the following order: 1) Mechanical construction 2) Other technical safety measures 3) Warning for remaining risks (signs/ user guide/ ) The next step is to finalize the engineering of the machinery. PAGE 7
After engineering, a risk evaluation has to be done. First the limitation of the machine has to be defined Then the dangers of every work process and function can be identified The risk of every situation has to be estimated as we saw in the risk graph (measure of damages, occurrence probability, possibility of avoidance/ limitation) The process has to be repeated until the remaining risk is evaluated as being acceptable! What could this mean in practice? Think about Oversizing (safety factors on steel cables and components ) Redundancy (critical safety function elements double executed) Control system safety (as SIL or PL) Et cetera PAGE 8
What is SIL? SIL is the Measurement of performance required for engineered set of hardware and software controls used on critical process systems (wikipedia.org). With the Safety Level SIL 3 the risk we want to reduce is decreased a 1.000 to 10.000 times. The Safety Level SIL of a control system is determined similar to the risk graph we saw above: For a better understanding, what does this mean for a stage technology installation used during a play (with movements above people)? The consequence of fly bars coming down can cause Cc Several Deaths. The frequency of people exposed to danger (underneath fly bars) is Fb Frequent to Continuous. As actors are immersed in the play and a signal for downward movement is not possible during a performance the possibility of avoiding is Pb Almost Impossible. At least, the probability of occurrence as fly bars are not moving the whole time is W2 Slight. According to the SIL risk graph the system has to be a SIL 3 system. An installation not used during plays or without movements above people would change Fb Frequent to Fa Rare, the result therefore would be a SIL 2 system. PAGE 9
3.2 Machinery inspection and maintenance The conditions of machinery inspection and maintenance have to be indicated by the manufacturer of the machine. Usually you will find them in the maintenance guide. In the Netherlands and Germany, for reasons of accountability, inspection by a qualified person must take place once a year. An inspection must also be planned after reparation, improper use or modification of the machine. According to the maintenance guide, there will also be frequent inspections a user must conduct. Typically inspection by user of the machinery is: Check conditions steel cables Check winding of steel cables on drum Check cable routing and pulleys Check problem reports of software and frequency regulator Check logbook notations Observe mechanical noise Check function of emergency stops Check wiring especially of controller Et cetera PAGE 10
3.3 Operating stage machinery For a safe handling and operation of the installation, the operator has to be qualified and experienced. Further is the primary rule: never operate without sight on stage and movement! Preperation The operator has to prepare his work well: Make a performance risk assessment o Check probability of all possible dangers and damages (falling persons, squeezing, turning over scenery, ) o How to avoid or minimize these risks, take these steps Topview of the ceiling, opera Die Zarenbraut, Opera House Frankfurt am Main, Germany Write a fly bar layout with scenery, weight and position for each fly bar o Check max. load, calculate load with speed, revise plan if necessary Generate a scene change list Draw plan view and cross-sectional view with scenery (usually CAD plans can be loaded into the control software) Programme the show Fly plan of the Kilden Performing Arts Centre, Kristiansand, Norway PAGE 11
Execution On stage the working conditions and flows also have to function: Clear responsibilities and division of work The operator has to give a loud signal for downward movement of flying constructions (like screaming head up ) so people around are informed (look up!) (of course not during performances) Watch over: o The safety on stage o Fixed scenery during movements o Working materials (e.g. to couple fly bars with) o Quality of execution (e.g. that the fly bars are coupled the right way) Scene change rehearsals (with and without actors) During performance: o Anticipate on action on stage o React accurate on unexpected situations PAGE 12
3.4 Conclusion The advances of automated theatrical rigging systems are obvious. Programmed software opens undreamed-of possibilities in controlling all extremes of synchronization and individual movement at the same time, while also guaranteeing a perfect repeat of a performance. Whereas it is better for the employees health and reducing the number of employees, perhaps it s greatest advancement is its ability of facilitate communication between the arts and technique. But what about safety? Since the changeover to automated stage technology in the Netherlands in 2007 no serious accidents have happened. As we have a look at the safety factors during manufacture, a system mainly gets unsafe by false handling after the handover. It needs yearly inspection to make sure that the system technically stays safe. Safe working conditions always depend on the action of the user, no matter if the system is automated or manual. It is important to teach operators and theatre technicians working with automated rigging systems never to rely on the safety of the system. Of all things the behaviour of operator and stage technicians plus the correct instruction and communication with the entire stage team remain indispensable. Laura van Haperen, Trekwerk B.V., Dutch Voting Delegate of the Oistat Technology Commission Please feel free to contact me at lpc.vanhaperen@gmail.com PAGE 13