This is a really horrible approach to getting lights mounted in the beam lighting position. There are solutions that are safer and more aesthetically pleasing for the room.
The main problem is functionality: You have 'bounce the lights' to even get close to a reasonable focus. If the winch runs at 15 feet per minute (fpm) (a typical speed), and the truss is 25-30 feet in the air, it takes about minute and a half to raise or lower the truss. Each time you start or stop the truss, the lights jiggle a bit and get a wee-bit out of whack. You have to look at the lights, figure-out how each one needs to be adjusted (tweaked), wait until it is lowered, make all of the adjustments to each lighting instrument (wild guesses mostly), run it back up, survey the situation, and the repeat the cycle again. This can go on for hours . . . each time you get a bit closer to what you want, but it is very exasperating. Oh, did I mention that the trusses sway a bit after moving (particularly if the air vents blow on it), so you have to wait for it to stop moving to really understand what your lights are aimed at.
Inconvenience aside, there is always a temptation to get a ladder out and try to adjust the lights in the air. This can be very dangerous over the seats! Unless you have 100% guaranteed supervision of your students, you can't be sure that none of them will try to be helpful and attempt to make adjustments this way. The other consideration is that if it is an electric hoist (it better not be a hand cranked hoist!), then it will need to have a control panel located where the operator can see the truss moving up and down, and that control panel must have a key locking switch (among many other safety features too numerous to mention here). If that control panel key gets left where the students can access it and run the winch unsupervised, it creates a huge liability for you and the school. Then there is the temptation to 'ride the truss'. Given the opportunity and lack of supervision, some student(s) will think that they can ride the truss up and adjust the lights in the air . . .
Inconvenience and safety aside (do we really want to put safety aside?), a big truss hanging ugly across the ceiling of an otherwise nice auditorium is a sure visual distraction for the audience.
Inconvenience, safety, and ugly aside, there can be an issue in some buildings of having enough structural capacity to support a large truss spanning the auditorium. This assembly is full of lights, hoist motor(s), wiring raceway (plugstrip), and the self-weight of the truss structure. This has to be assessed by a structural engineer to make sure the weight is attached and distributed properly. This is a 'live load', not a static load, so if you have a ton of gear in the air (yes, this stuff adds-up fast), then the loading on the building is considered to be twice as much (2 tons).
There are other ways to do this that are safer (with proper training and supervision), less ugly, weigh less, and facilitate aiming the lights in-situ without a whole lot of wiggling going-on.
Odds are, if you have a venue with no front lighting positions, then it may be old enough that the house lights and ceiling need a major renovation anyway. This is the time to upgrade the house lights to LEDs, add stage lights, improve the room acoustics (better ceiling design), and possibly quiet-down a noisy air duct system all at the same time. Toss-in a fresh coat of paint to spruce-up the space a bit, too.
Will this renovation significantly tear-up the ceiling? Maybe. If so, seize the opportunity to update the seating, too. Older auditoriums can have narrow seats that don't fit the modern audience's rear-ends. Wider seats may reduce your seats/row count by one seat. Older seats may be wood or thinly padded plastic - this is both uncomfortable and it makes for poor acoustics. If yo have seats that do not automatically fold-up the seat pan when not occupied, it is probably in violation of the Fire Code egress regulations. Good quality padded seats present the same amount of sound absorption to a room whether it is occupied or not. This means the room acoustics don't change significantly depending upon the number of tickets sold. This is better for band, orchestra, drama, lectures, and choral presenters. If the ceiling is needing renovation, this is the perfect time to replace the seats - take out the old ones, renovate the ceiling, then install new ones (and get some new carpet on the floor, too!).
Plan for a real improvements to the auditorium, don't just scab-on a short-term solution. Involve professionals (insert shameless plug here) to get it right and plan a composite renovation so everyone can enjoy your space.
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Erich Friend
Theatre Consultant
Teqniqal Systems
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Original Message:
Sent: 04-10-2017 13:41
From: Susan Draus
Subject: Light truss on a winch?
Has anyone had experience with a lighting truss on a winch? It can be lowered for bulb change and focus, then hoisted back up for performances. We're thinking of installing one over our audience. Any recommendations? Problems? Considerations?
Mrs. Susan Draus
English/Theater Arts
Downingtown High School West
445 Manor Ave. | Downingtown, PA 19335
P: 610-269-4400 ext. 7921 | E: sdraus@dasd.org | W: http://www.dasd.org/dhsw
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