Hanging by a Thread: Rigging

CHAPTER TEN

IN THIS CHAPTER

Ropes

Knots

Rigging Systems

Study Words

Now that the scenery is built, how do you get it into place? How do you get it into its storage position? Does it fly in and out, does it track on and off, or does it just sit there? Once you know the answer to these questions, the solution lies with the rigging department. Rigging is one of the most critical, and therefore dangerous, parts of theatre. We build scenery that is heavy and then we hang it over people’s heads. We hang pipes with many lights and cables on them … over people’s heads. If any of that weight falls down, it can be disastrous.

Rigging at its most basic is all about knots. Where do we get these knots? Again we will honor the history of knots, which all come from sailors! Once we learn about the knots that make theatre rigging safe and easy, we’ll move on to more complicated rigging where new technology has really made a huge impact. Fifty years ago if you wanted a platform to move across the stage somebody had to push it! It sure is different today with the advent of mechanization.

The earliest stagehands in history were also sailors. Many of our knots, ways of rigging, and general traditions come from the standard uses on boats. More modern equipment and techniques come from mountain climbers. It is an interesting combination that gives the theatre the capability to fly things into the air.

ROPES

Let’s start at the beginning and talk about rope. You can pretty much divide rope into two basic categories: natural and synthetic. Natural ropes are made from a wood pulp fiber that is harvested from plants like jute, hemp, and bamboo. The fibers are then twisted and/ or braided to add strength to the fibers. Watch out for splinters as the rope ages, especially if you might be allergic to hemp! There are no longer any advantages to natural rope. It starts degrading the moment it is made, because it was once alive. It is losing its moisture and elasticity; basically it’s biodegrading.

FIG. 10.1
All of our rigging techniques and traditions come from sailing. Take a look at this fully rigged boat for comparison.

Synthetic fibers include nylon and polyester. Synthetic ropes are made through the twisting and braiding process as well. Abrasion, chemicals, heat, and UV (sunlight) will all affect synthetic rope and cause it to degrade. Rope can also be made from wire, but we will discuss that later in the chapter. Originally theatre used natural rope because it was the only option. Natural fibers are subject to changes to heat and humidity, which can make them stretch. Synthetic fibers don’t have this problem and therefore can have a longer life. The replacement schedule for natural rope is five years, whether it has been used or not. There is no replacement schedule for synthetic. It lasts practically forever.

Both types of rope come in a variety of thicknesses and lengths. The material the rope is made from, the thickness, and the manufacturing process all combine to give the rope its strength rating. Always check a rope’s rating for how much weight it will hold before you use it. The best advice about rigging I can give you is to be cautious and never attempt anything you are unsure of, and always ask for help if you need it. One last thing, wear gloves when working with rope. It will help you to keep a good hold on the rope, and should the rope slip, you will not hurt your hands. Rope burns are a total drag, so avoid them at all cost!

FIG. 10.2
Backstage at the 1869 Bardavon Opera House. Look at the rigging both below the loading floor and above it.

FIG. 10.3
Natural rope made from hemp.

FIG. 10.4
Synthetic rope made from nylon.

KNOTS

Knots are the basis of rigging. There are many different knots, and a handful of those are critical to theatre. The overhand knot, square knot, bowline, clove hitch, belaying, and coiling are all essential to theatre rigging. The overhand knot is the simplest of them all. Hold the rope with both hands parallel to the ground; cross it over to form a loop; wrap the right-hand end through the loop; and pull! Congratulations, you’ve learned a knot. Of course, you probably already knew this one—and be careful not to use it too much since it is the one knot that can destroy rope faster than any other.

The square knot is the basis for so much. Almost everyone knows how to tie this knot, or at least has heard of it. Also known as a reef knot, the square knot is secure and easy to untie. While holding both ends of the rope, cross the right side over left and wrap around the left, just like when starting to tie your shows. Then cross the left over the right and wrap. Pull to make the knot tight. To untie, hold both ends and both sides of the loop and push them toward each other.

FIG. 10.5
Overhand knot step-by-step.

FIG. 10.6
Square knot step-by-step.

The bowline is my personal favorite. I learned it in Girl Scouts where we were told to recite the following story while tying the knot: The little bunny comes out of the hole, walks around the tree, and goes back in the hole. OK, so you’ll understand that better after I describe it more fully. A bowline is one of the most important knots to know. If properly tied it will not slip and can be used to secure things or lift people. Hold one end of the rope in your left hand. With the portion of rope in your left hand, make a small loop in the rope above your hand with the part going away from you on the under side of the loop. With the piece of rope in your right hand feed it through this small loop from the bottom. Take it around the piece of rope going away from you. Bring the end back down through the small loop. Pull the end tight.

FIG. 10.7
Bowline step-by-step.

The clove hitch is very important to almost every rigging job in the theatre. Used as a traditional hitch that is securing only one end, the clove hitch is liable to slip. It requires a load attached in each direction in order to be effective. Since the clove hitch is almost always a load-bearing knot, it should not be tied with rope that is thin or very slippery, as it can work itself loose, especially under a swinging or rotating load. However, for this very reason, the knot is useful in situations where the length of the rope ends need to be adjustable. It can also jam and become difficult to untie under some situations, so be aware of this.

To tie a clove hitch, first place a loop around the pipe, with the working end of the rope on top. Run the working end around the pole once more until you meet the place where the ropes cross, then pass the working end under the cross. Pull to tighten. Sounds easy, right? Well, going correctly under the cross can be confusing, and it is the step that makes the clove hitch secure. Practice this repeatedly until you can do it almost without having to think about it.

FIG. 10.8
Clove hitch step-by-step.

You can use the clove hitch to join two pieces of pipe or wood together. You can also use it for pulling a straight length of pipe up into the air. To do this you will need the half hitch. The half hitch is really a cornerstone knot that forms the basis for a multitude of other knots, and so you should take the time to truly master it. By itself, it is not particularly reliable. To tie a half hitch, loop your rope around the pipe. Cross the short end under the long, main length of the rope. Bring the short end over and down through the hole between where the rope crosses and the pole. Push the knot to the pole, and pull to tighten!

Now you can raise straight pipes using a combination of the clove hitch and the half hitch: Grab the pipe, tie a clove hitch at the bottom, flick the rope around the top, and do a half hitch to pull the pipe up without it flailing. Now you’ve got the basis for knots in the theatre. Most other knots are based on these. Once these are mastered, all the other ones will be easily learned.

Belaying is not technically a knot, but it does have to do with all of our rigging. In order to belay, you will need a cleat or pin. The goal is to secure a rope by winding it in a figure-eight pattern around the cleat. To secure the belay, the final figure-eight wrap gets a 180-degree twist before being put on the cleat. Pull down on the working end of the rope to tighten.

A quick note about working with any kind of rope. Every time you tie a knot in it you weaken the rope at the point of the knot. Keep this in mind and realize that rope does have a life span. Knowing all of this helps you to properly store rope in order to extend its life and keep your backstage area as clean and safe as possible. This brings us to the last knot I will discuss, and again it is not actually a knot.

FIG. 10.9
Belaying step-by-step.

Coiling rope is one of the few ways you can safely store rope without putting any bends, kinks, or knots in it. It doesn’t take much time to learn or to do on a regular basis. Once you are in the habit, you’ll wonder how you continually stepped over piles of rope in the dark for so long. To coil a rope, take one end and make a big loop. The loop size will change depending on the diameter of the rope, but let’s say it should be around 18 inches. Continue to loop more and more of the rope in this way until you have about 2 feet left. Hold the looped rope in your left hand and grab the remaining rope in your right. Begin to wrap the remaining rope around the top of the loop; it will probably take five to six wraps. Then thread the loose end of the rope through the coils and pull tight.

The monkey’s fist is an interesting knot to know about based on its history. I won’t explain how to tie it, as you will probably never need it. However, there are interesting stories about it and it is a fun knot to know about. Sailors on boats originally used the monkey’s fist. Once the knot is tightened it adds a substantial amount of weight to the end of the rope. This allowed the sailors to throw the rope up into the air, hope to go over something, and have the rope come back down. The extra weight helped that last part. Putting a stone or marble into the fist and tying the knot around it is the original way to do it. This added more weight, but also made it easier to tighten the knot. The key with this knot is not tying it, but tightening it. I like to tie it without the stone or marble as more of a challenge.

FIG. 10.10
The monkey’s fist is a knot that is more about tightening than tying. It’s fun to attempt once you are more advanced.

RIGGING SYSTEMS

OK, now that you’ve learned the basic knots, let’s start looking at the basic rigging system within a theatre. All theatres will have parts of the following in common. There will be differences, and I will point these out along the way. Let’s start by talking about line sets. Line sets are the individual rigging points for hanging pipes and scenery in the air. It doesn’t matter how they are hung, if they are in the air, they are line sets. The line set inventory will tell everyone where the pipes are in relation to the plaster line. That way everyone has a line that they can all reference. If everyone agrees to the same point of reference, then any information after that will all be coordinated.

There are four basic rigging systems that you will be exposed to over time while working in the theatre: hemp house, single purchase, double purchase, and winch or automated. We’ll look at each system one at a time, explaining the varying reasons for each. All are still in use today at different theatres, and all are viable options for many of the techniques you’ll learn that carry over to other rigging topics we’ll discuss. Don’t think that you’ll ever run into a hemp house or a double purchase system and just ignore the information. There is something within each style to learn from and use elsewhere.

HEMP HOUSE

I spoke with Jason Adams at the 1869 Bardavon Opera House while they were renovating their stage house. Jason said they had evaluated many options before deciding to stay as a hemp house. A hemp house or rope house is defined as such since the lift lines from the battens are rope, organic or synthetic, not wire. A hemp system is counterweighted with sandbags tied onto the lines. Wow, hang on, what is a counterweight? A counterweight is used to offset the weight of what you are trying to lift. Think of a seesaw: There is a pivot point in the middle and a child sits on one end, which makes that side drop to the ground. If a child sits on the other end (providing a counterweight), then the first child can rise into the air.

The locking device to make sure nothing falls down unexpectedly is a pin rail. Belaying, which we just learned, is done using the working end of the rope and the pin rail. When you do this, keep in mind you are holding all the weight until you get it tied off. The same is true when you are untying the line. Make sure you have a good hold on the rope above the pin rail. Once the belay is released you will be holding all the weight.

The next step in the rigging progression is to add weight to the working line before belaying to the pin rail. This is the counterweight that helps to balance the weight on the other end of the rope. Sandbags are just what they sound like: a bag filled with sand. They come in a variety of shapes and sizes. The difference in the sizes changes the amount of sand and therefore the weight of the filled bag. The goal is to add enough sandbags to the working end of the rope to equal the weight on the other end.

FIG. 10.11
Sample line set inventory.

In order for all of this to work properly, there has to be a number of pieces or hardware in place. Let’s discuss those now so we can get a bigger view of the rigging system. We’ll look at each type of system individually. Some of the hardware repeats for each system, so as we go it will get a little easier. Let’s start with a hemp house. Hemp rigging is the simplest of all the rigging systems. Let’s get some vocabulary out of the way. A sheave is basically a pulley. It has a groove around its circumference to support and contain a rope and a bearing at its center to permit rotation. A block is an assembly that consists of one or more sheaves in a housing. A spot block is designed for a temporary and easily movable connection to a gridiron or other theatre structure. A head block is a pulley mounted to overhead steel above the fly loft that changes the direction of multiple ropes. A loft block is a pulley mounted to the gridiron or support steel that supports and changes the direction of a lift line rope between the load and the head block. The following diagram illustrates how all the parts we’ve just talked about go together.

FIG. 10.12
Even the rigging backstage can look awesome with the right lighting!

FIG. 10.13
Seesaw with a center pivot point.

The rope attaches to the pipe with a clove hitch. Then the rope goes straight up to the loft block. The rope could also go to a spot block. All the blocks have pulleys so the rope goes through it in order to make a 90-degree change of direction. Due to the width of the rope the groove is U-shaped. Usually there are three or five ropes attached to the pipe. All of these now go over to the head block where they go through their individual sheaves and turn direction again. The various blocks have to have enough sheaves to accommodate the number of ropes per pipe. Once the ropes come out of the head block, a sandbag is attached. Then the ropes continue down to the pin rail where they are belayed to secure them.

FIG. 10.14
Sandbags on the floor backstage, waiting for their next job.

If you are dealing with something that is extraordinarily heavy, you can add a block and fall for an additional mechanical advantage. A block and fall is a piece of equipment that simulates the standard blocks allowing multiple ropes to come in through the top. The difference is in the “fall” side as it reduces the number of ropes coming back out down to one. The ropes coming out of the head block are now tied off to the top of the block and fall. This reduces the number of ropes to one and also the overall weight to make it workable for one stagehand to move the pipe. The bottom of the block and fall is fixed to the pin rail.

Keep in mind the goal is to balance the weight to keep it in place, and make the pipe lighter in order to get it moving. If you have to choose, you always want the pipe to be slightly heavier than sandbags so pipe is more likely to drift down rather than up. This helps when you are flying pipes into the floor, and doesn’t really affect anything when the pipe is tied off. A dead lift is tough, meaning trying to lift the full weight without any help from counterweights. You can’t get enough hands around the rope to physically lift heavy items. Plus, the stagehands have to take one hand off the rope to move their hand higher before pulling again.

FIG. 10.15
Diagram of a hemp house.

SINGLE PURCHASE

Before we change topics to single and double counterweight systems, let’s introduce some more vocabulary. We are now changing from using synthetic rope to using wire rope. Wire rope consists of a number of strands twisted on the diagonal around a core. Each strand consists of a number of wires twisted on the diagonal around a core. You can see how strong it can be! A thimble is a grooved fitting around which a wire rope is bent to form an eye. It supports the rope and prevents it from kinking and wear. In order to hold the thimble in place, you use a wire rope clip. This is a U-shaped bolt and a pad with two holes for sliding up the bolt. Two small nuts are used for holding the pad in place. The wire rope comes out of the thimble and doubles back on itself. Both pieces of rope go between the bolt and the pad. Once the nuts are tightened, the wire rope stays securely in place.

FIG. 10.16
(1) -inch wire rope sling, (2) -inch wire rope, (3) locking carabiner, (4) -inch wire rope clip, (5) -inch thimble, (6) -inch shackle, and (7) 3-foot spanset.

The arbor is a carriage or rack that contains weights, usually cast iron called pig iron. The loading floor is where the technicians add and remove counterweights from the arbors. It is usually located so that technicians can change the weights when the pipe is at the lowest level.

In both single and double purchase systems, the rigging overhead is identical. Wire rope goes up to the loft block. Blocks can be shaped differently depending on how they are to be hung and how many ropes must pass through them. As wire rope is thinner than synthetic rope, it uses a V-shaped track in the blocks. The wire rope goes through the head block and down to the arbor. A wire rope then connects directly to the arbor. The hand pull is a big, thick, synthetic rope that attaches to the bottom of the arbor and then goes around to the head of the block. Pulling on the hand pull raises and lowers the pipe.

In a single purchase setup the loading floor is on the stage floor. This means you will lose a lot of stage space in wings to accommodate the arbors. The advantage of the single purchase system is that the counterweight requires a 1:1 ratio. You will need to add one pound on the pipe for every one pound of arbor weight.

DOUBLE PURCHASE

A double purchase system puts the loading floor halfway between the stage floor and the loft blocks. There is also an extra pulley both above and below the arbor in order to double the wire rope length. This is necessary in order to make this system work properly. The pipe travels 1 foot for every 2 feet the rope has to travel. You will need to use twice the amount of weight of what is hung on the pipe. The advantage is that you do not lose any floor space. This is often the major deciding factor in which type of system to use.

Let’s look at automated systems next. Winches are geared mechanisms that can be either hand operated or motorized. They are used to raise or move heavy equipment. The gearing produces a mechanical advantage in both speed and load capacity. As a transition between counterweight and winches, let’s look at the counterweight assisted winch setup. This is a motorized winch that is retrofitted into existing manually operated systems that use counterbalancing weights. The counterbalancing weight will be fixed at 50 percent of the maximum capacity of the set. The winch is rated at 50 percent of the maximum capacity of the set. By using the winch it will operate the line set at any load from 0 to 100 percent of its rated capacity, without the need to ever adjust the counterbalancing weights.

Fully motorized systems contain one of two types of winches: single drum winches and line shafts. A drum winch system has a head block and loft blocks just like a regular counterweight system. This is a good way to motorize a system and balance the costs. The line shaft winch has a drum for each lift line, which eliminates the need for blocks. The biggest concern with the line shaft system is the cost. If your system has 30 line sets, you will need 150 drums.

TRUSS

A truss is our next concept in the realm of rigging. A truss is two or more pieces of pipe fabricated together with crossbracing. This is used in place of standard pipes when you have extremely heavy loads to lift, or there are extended distances between lift lines. Trusses come in a variety of shapes and lengths. There are flat trusses, triangular trusses, square trusses, and then any kind of custom shape you can think of.

FIG. 10.17
Diagram of a single purchase system.

Spansets, generically known as round-slings, are continuous loops of monofilament or steel-galvanized aircraft cable in a canvas-like (polyester) sheath. The number of loops used determines rating or weight capacity. A wire rope sling is an alternative to the spanset. A wire rope sling is made from larger gauge wire rope and is fabricated with a large eye and thimble at each end.

In order to use the spanset or wire rope sling you will need a shackle. The shackle is a U-shaped device with holes at each end to accommodate a pin or bolt. There are three different configurations for using a spanset with a shackle. The strongest of these is called a basket. This is made by creating a U shape out of the spanset. It gives you four points of contact. The next configuration is to use the spanset straight. This will give you two points of contact. The last is the choke. You wrap one end around and then put one through the other. It is not as strong since a bend weakens the line of the spanset. Of course there are ways to shackle two spansets together for more length and flexibility.

FIG. 10.18
Diagram of a double purchase system.

I cannot stress enough how dangerous rigging systems can be if they are not used properly. Regular inspection prevents a lot of problems. The person operating the system needs to pay attention to every part of the system. The initial installation needs to be done properly, of course. Regular inspection should be a continuous process during the use of equipment, as well as one or two times a year for a complete maintenance inspection. With that said, if you do the job well, there will be time to relax between cues.

FIG. 10.19
Hick, a rigger for the 1869 Bardavon Opera House, stands next to a 1-ton chain hoist box during a load-in.

FIG. 10.20
A box truss with chain hoist attached, waiting to be raised.

FIG. 10.21
A curved and box truss at Production Resource Group.

FIG. 10.22
At the end of a long call, the riggers get a chance to relax!