Issues in public assembly facility design, operation and maintenance.

This was a good show for us!

Here are the answers to the questions we submitted (the organizers of the show chose to use the light source technologies question).

Four options to support and access performance lighting in front of the proscenium include catwalks, tension grids, dead-hung battens and battens (pipes) on some type of hoist or lowering system.

• A catwalk (or lighting platform–this is NOT your classic catwalk as the railings are intended and spaced to support lighting functions) allows easy access to fixtures but must be carefully placed to be effective.  Too close and the light will be aiming almost straight down, causing heavy shadows particularly in the eyes.  Too far, and the lighting becomes very flat and uninteresting.
• Tension grid, which is a woven steel cable mesh, provides the greatest flexibility.  Lights are above the mesh and shine through onto the stage below.  The mesh does not affect lighting (or sound) going through it with one exception: PAR fixtures.  The beam of light is parallel enough to project the image of the mesh to the surface below.  Lights can be used anywhere above the surface as needed.  The cost is about the same, per square foot, as catwalk while weighing less.  It is also possible to rig through tension grid.
• Dead-hung battens are surprisingly common and about as inconvenient as possible.  This is also the least expensive, initially, of the available options, as it is nothing but a pipe suspended from chain, cable or threaded rod directly from the structure above.  Like catwalks, these must be carefully placed to be effective.  Access for maintenance and focusing is ideally from a lift (although seats frequently interfere) or from a ladder, if low enough.
• Hoists for this application come in many flavors, each of which has its strengths and weaknesses.  Lineshaft winches, dead-haul drum winches, package hoists, self-climbing trusses, trusses with chain motors, counterweight assisted winches are just some of the options.  There are also manually-cranked winches and other variations.  The major weakness, other than placement, is that focus (aiming) of the lights will take extra time as the hoist has to be raised and lowered repeatedly to focus the lights by trial and error.

Next up are the three most common stage rigging technologies being installed in current theaters, churches and auditoriums.  Those are manual counterweight, powered hoists and dead-hung.  What is appropriate for a given stage and application varies with the space, the users and the intended uses of the system.

• Manual counterweight systems operate by balancing the load (lighting or scenery, typically) with steel counterweights.  There are variations even within this type of system (single purchase, double purchase, motor assisted, etc.)
• Powered rigging systems are most commonly seen in the form of package hoist systems.  These are standardized zero fleet-angle winches that operate on a common backbone (power and control) and usually have a common control point that often allows grouping and presets.  Other types include lineshaft winches and dead-haul winches.
• Dead hung rigging includes any rigging suspended in a static manner from the structure above.  Some examples are studio pipe grids and curtain tracks that do not fly.

The two dominant lighting source technologies at the present in the theater world are tungsten-halogen and LED.  Fluorescent is used heavily in TV studio applications.  LED technology is rapidly evolving and quickly gaining ground on traditional halogen sources.  Already, LED cyclorama lighting fixtures outperform their conventional counterparts–at least when the rich colors typically used on a cyc are involved.

Finally, the role of a theater design consultant.  Primarily, the design consultant’s role is to provide options to the design team.  Once the function of the facility and its primary program functions have been determined, HOW to accomplish those goals becomes the next puzzle.  In presentation environments, there are many ways to accomplish the same end–and each has its own strengths and weaknesses.  What is right for one user may not be appropriate at all for another.

We’ll be exhibiting at the Trade Show sponsored by the East Kentucky chapter of the American Institute of Architects and the Bluegrass Chapter of the Construction Specifications Institute.  Look for us in Booth 31 at The Crowne Plaza Campbell House in Lexington, Kentucky.  We’ll be happy to help answer the questions to Construction Jeopardy.  Our questions:

• What are four options to support and access performance lighting equipment location in front of the stage (over the audience)?
• What are the three most typical stage rigging systems currently being supplied and installed on stages, in auditoriums and churches?
• What are the two dominant lighting source technologies at present for theatrical presentation facilities (including churches)?
• What is the role of a theatre design consultant in a typical project?

(Answers later or come see us in Lexington!)

I was speaking with an architect a few weeks ago and mentioned that, as a consultant, we carry professional liability (“errors and omissions” or E&O) coverage for our design services.  We see this as a tangible benefit to our clients and potential clients.  Why?  And what does it mean to you?

In very general terms, a professional liability policy covers us–and our clients–for damages (economic or bodily injury) that are incurred as a direct result of the performance of our specific design consultation services.  Our policy is much the same as that issued to a licensed design professional–an architect or engineer.  It’s important that all of the design professionals involved in a building carry this coverage.  The major reason why is buried in our commercial insurance policy, which is likely very typical in that it excludes liability from professional design services.

One requirement of our professional liability policy that is, again, likely very typical: we are required to ensure that our design subcontractors carry their own E&O coverage.  The implication of this is that an architect or engineer that hires us as a designer should be requiring this coverage from us, as well–it’s likely to be a requirement on their policy as well as, we think, a generally good idea to protect both themselves and the end client.

We were recently asked for our advice regarding stage drapery and humidity control.  Below is essentially the text I shared.  This system is fairly typical of many auditoriums: all of the drapery is manufactured from cotton fibers and is hanging from a counterweight rigging system.

Cotton fiber, without any treatment, is flammable.  To meet building code requirements, the cotton fabric used in your drapes was run through a flame retardant solution.  This solution is a blend of metallic salts that help to prevent the fabric from sustaining flame.

We strongly recommend maintaining a humidity-controlled environment for natural-fiber fabrics for several reasons.

1. Untreated natural fibers in a humid environment will deteriorate at a faster rate—moisture accelerates decay.
2. The salts used to flameproof this fabric are hydroscopic and will “pull” moisture from the air.
3. Salt, combined with moisture, is corrosive and will further accelerate decay of the fibers.
4. Large drapes can soak up a significant amount of water from the air.  Even if the rigging system was left balanced, the water in the drapery can dramatically change the balance of the lineset.  This is, at best, an unpleasant surprise for the next operator of that lineset.  At worst, this is a recipe for a runaway lineset that can result in serious injury.
5. When the fabric is weakened, the additional moisture (weight) has the potential to tear the drape away from its reinforcing webbing at the top.  This has a similar result to the scenario described in #4, above, except that the out of balance condition is in the other direction.  The results have the potential to be just as unpleasant.

There are other drapery fabrics that were either not available or not of an acceptable quality at the time the system was purchased.  These velour fabrics are made from polyester and are inherently flame retardant—meaning that they do not require treatment and the side effects that come with it.  These fibers will not deteriorate because of moisture.

As long as the drapery in use is fabricated from cotton, we believe that their environment must be humidity controlled.  One of the fabricators that we work with regularly states that they will not warranty cotton drapery that has been subjected to more than 65% relative humidity.  Failing to control the environment both creates a significant safety hazard (that increases that the drapery ages) and shortens the life of the fabric.