Issues in public assembly facility design, operation and maintenance.

This is probably the oldest, and simplest, style of stage rigging technology.  This label for overhead rigging generally includes:

• spotline rigging (one or two lines placed temporarily to raise and lower or otherwise manipulate a single scenic piece)
• 3 or 5 line linesets
• head blocks (with multiple sheaves) and loft blocks
• rope used as the lifting material
• one or more pinrails

Flipping this list around, an essential piece of this technology is the pinrail.  On a sailing ship, which is the source of much of this technology, this would be either the fife rail (around the base of the mast) or the pin rails at the bulwarks.  In the theatre, this is either a timber or pipe, typically with holes punched every 12-18 inches for the belaying pins.  Traditionally, the belaying pins are removable for the simple reason that you can release a line very quickly by simply pulling the pin out (preferably while holding the rope!).  Modern pin rails are sometimes fabricated with pins welded into place.  Like so much theatre technology, pin rails have not disappeared with the advent of newer systems; many new theatres are still built with this device.

The rope, on the other hand, has changed.  Natural fiber (hemp or manila) has been nearly universally replaced with synthetics.  The simple reasons are strength and longevity.  Natural fibers are sensitive to moisture and will deteriorate over time.  This is not an issue with synthetic fibers.  There are trade-offs, however.  The synthetic fibers can be more slippery and can me more costly.

Like many things, there are advantages and disadvantages to this style of rigging.  Some advantages:

• Flexible–especially in a stage with a gridiron, setting a spot block and running a spot line is a very quick, simple process.
• Nearly silent–if the equipment is in good repair, the only noise from a rope system is the rope whispering over the blocks.
• Trimmable–it is very simple to adjust for trim (level) across any given lineset.
• It is possible to add counterweight, with either a Sunday or trim clamp.

There are also some drawbacks:

• It takes a very high level of skill to set up and use a rope system.
• Much of the time, the linesets are unbalanced.  This is an inherently unsafe scenario and has to be handled thoughtfully and with caution.
• It is very easy for a lineset to get out of trim (level).

The type of facility you would typically see a full-blown rope system would be in a smaller facility that most frequently utilizes painted fabric scenery–essentially, the average theatre from the 1930′s and earlier.

Spot line rigging, on the other hand, is common in many theatres and most especially in those with a gridiron, as the gridiron makes it very easy to rig.  This includes theatres currently in various stages of design or construction.

A technician working with a rope rigging system needs:

• to be able to estimate weights
• to be able to handle the amount of weight hanging on the other end of the rope
• a basic knowledge of knots

Like any rigging system, a rope rigging system should be regularly inspected, including having a periodic professional review (we recommend annually with all rigging systems).  The other major maintenance items are keeping the lines coiled and neat–off the floor, away from dirt–checking the condition of the rope and ensuring all knots are securely tied.

This is the kind of rigging system usually visible in movies showing a theatre.  It is far more “theatrical” and interesting visually than counterweight sets or winched sets–in the case of the last, there might not be anything to look at except the controller!  Watch for sandbags and coils of rope on the screen.

All stage rigging systems have essentially one goal: to hold material (scenery, lighting, masking drapery) in the air–safely.  There are many similarities between the various systems that have been devised to do that job.  There are also significant differences, mostly dependent on exactly what you want to do with the scenery and how you want to do it.  Here’s an overview of each type of system.  Later articles will look at each type in detail and discuss the strengths and weaknesses.

Dead-hung.  This refers to rigging systems that cannot be moved vertically.  Typically, this consists of pipes or tracks suspended directly from the building structure with chain or cable.

Hemp.  These are the systems we see frequently in old movies with 3-5 ropes and sandbags.  The name comes from a frequently-used rope fiber–although it is interesting that the majority of natural-fiber ropes used in the modern theatre building are spun from manila rather than hemp.  But that’s a different discussion!  The equipment is able to be moved vertically.  The sandbags are used to balance the load applied.

Counterweight.  It is probably a safe guess that this is the most common type of rigging system installed in theatres in the United States.  There are many variations within this category.  two big ones include how the arbors are guided and if the system operates in single or double purchase.

Manually winched.  The most common example of this type of system has one or two hauling lines from the winch to a clew, then multiple lift lines out from the clew to the batten.  These are typically used on equipment that needs to be accessed relatively easily but not rapidly or frequently.

Powered winches.  This is easily the most diverse category.  Hydraulics, packaged hoists, counterweight assist, dead-haul…the list goes on!

As I noted above, later articles will discuss each category in more depth and touch on the options, strengths and weaknesses.  In the meantime, regardless of the type of system, remember that it is suspending thousands of pounds of weight over people’s heads.  These systems should be inspected on a regular basis.  We recommend annually!

Last year, one of our projects featured examples of four of these–on the same stage, at the same time.  There were dead-hung line sets, some hemp sets (with one really old sandbag that basically disintegrated when it was touched), two different versions of counterweight and even a manually-winched set.  There were a lot of interesting “features” to that system.  One of these was the access system devised to allow relatively easy re-rigging of the hemp sets.  One of the down sides to a rope system is that if you accidentally let go of the rope, there is a distinct possibility that the rope will snake its way right out, over the block and into a nice pile–at the floor.  Since this particular auditorium did not have a gridiron, the designed solution from the 20s or 30s was this.  A center catwalk was installed running from stage left to stage right.  It was long enough to reach all three of the primary rigging beams.  At the far downstage and upstage ends of the rigging beams, there were squared steel “loops,” about 12 inches wide, hanging down to approximately the elevation of the catwalk.  We could not figure out what they were until we noted the 2×12 plank laying on the floor.  We finally made the connection.  The intent was that you’d carefully extend the plank out from the catwalk into the loop.  One end of the plank rested in the loop, the other on the edge of the catwalk.  That allowed a worker to walk out, balancing on the plank,to re-reeve the offending line into the block.