The entire stage is worth study, but the fly tower is what we will investigate in this article. [Editor's note: this article is based on Chapter 6 of Rick Boychuk's book, which he plans to publish in the spring of 2015.]
The roof supports the greatest portion of the load of the gridiron, the galleries, and the flown scenery. The walls carry the balance. Rods attached to the roof descend to the beams of the gridiron. The various galleries are suspended from the gridiron on the onstage side and are attached to the walls of the stage house on the offstage side.
The main beams of the gridiron are small dimension I beams oriented across the stage. It is not apparent from the Moynet's drawing (fig. 1) how the gridiron beams and rods are attached to each other. Nor is it apparent how many gridiron beams are used or at what intervals.
Joists are laid onto the gridiron beam(s) at right angles, parallel to the center line. The distance between these grid joists is not defined, but they are frequent and appear to be around 0.75 to 1.0 meters apart (2.46 to 3.28 feet). This distance is estimated by counting the number of intervals between joists and dividing that number into 12 meters and 16 meters which are the typical distances between fly galleries in nineteenth-century stages.
As can be seen in figure 2, an enlargement of figure 1, there is a layer of boards on top of the grid joists. These are laid parallel to the plaster line. Although Moynet doesn't show it, there would have been a small space between each board to allow passage of loft lines.
The grid joists are mostly one piece of lumber. The exceptions are at center and immediately above the onstage faces of the fly galleries where the grid joists are in pairs. The reason for the double grid joists at center isn't clear, but one can see in the illustration that ladders and other vertical timbers were secured between the offstage pairs of joists. The reason for the double grid joist offstage is found in the drawing; ladders and additional vertical timbers are secured between the joist pairs. This same construction is evident in the Bourla Theatre in Antwerp, the oldest remaining European nineteenth-century theatre with its original stage machinery intact.
These timbers and ladders extend from the gridiron to the bottom of the first fly gallery; the fly galleries are attached to them. So, as well as being used to access the various fly galleries, the ladders are the suspension supports for the galleries. They also bear the upward compressive load of the cleat rails.
The cleat rail is a distinctive feature of both figure 1 and figure 3, as well as many other drawings of European stage machinery. It is made from a horizontal piece of square or rectangular wood of substantial size. This rail has pieces of lumber bolted to it in a vertical or slightly angled orientation These cleats, as shown in Moynet's drawings and in other drawings of older theatres, are not the sophisticated sculpted cleats of a nautical tradition, just simple short pieces of lumber with rounded corners and edges.
Moynet's cleat rail is not a continuous length of timber. Each length of rail is secured between the vertical elements of the galleries.
Below the cleat rail is another interesting feature, a rail at the bottom, like an ankle rail. This rail does not have cleats and it is cylindrical, possibly a pulley, although some drawings from other sources show an ankle rail that is rounded only on its underside. Figure 3 shows the flyman operating a line that appears to raise and lower a drop.
Supporting each fly gallery floor at its onstage edge is a double wooden beam that extends from the upstage wall to the proscenium wall. The beams would be bolted or dowelled to the sides of the ladders. Resting on these beams are the floor joists of the galleries, which extend offstage. The floor joists are at intervals of roughly 450 mm (17.7 inches). Boards are laid upon the joists forming the gallery floors. Although not apparent in the drawing, there would be openings in the floor at each ladder.
It is not evident exactly what happens at the offstage wall. Do the joists extend to the walls there to sit upon a ledger board? Or do they extend to a beam that is a distance from the wall allowing for an arbor well? This drawing is not clear. Figure 3 shows that an arbor well exists on both sides of the stage. How would a beam located even a short distance from the wall be supported? Moynet is silent on the point.
There are two types of bridges in this drawing: crossover bridges at the upstage wall and flying bridges over the stage playing area. Figure 1 shows a total of thirteen access routes from one side of the stage to the other. But, while the second and third galleries each have six bridges, the first gallery--supposedly the most populated with stagehands because it has the cleat rail--has only the one bridge located at the upstage wall.
The floors of the flying bridges at the second fly gallery are at the same level as the fly gallery floor. However, the floors of the flying bridges at the third fly gallery are raised to the level of the top of the rail. If the reason for the flying bridges is for quick access across stage, why introduce an obstacle to the flymen on the third gallery by making them climb the ladder to reach the bridge? Moynet offers only a hint of an explanation that goes beyond mere passage from one side of the stage to the other. He tells us that the flying bridges were spaced at intervals such that a man of average height could stand on the flying bridge and reach a piece of scenery half way between it and an adjacent bridge. Perhaps a secondary purpose of the flying bridges was to assist scenery on its way up and down, or perhaps to correct fouled scenery.
Figure 3 is Moynet's drawing of the counterweight and drum system for raising and lowering a drop. The drum, which is located on the gridiron, contains two drums of different diameters. On the drum with the smaller diameter we see lines A, B, C, D, and E. These are the loft lines. On the same smaller drum we see line F; this is the counterweight line. The counterweight line pays off the drum in the opposite direction to the loft lines, thereby balancing the load. On the drum with the larger diameter we see lines G and H; these are the operating lines. These lines pay off the drum in opposite directions. The flyman could raise or lower the drop depending on which of the two operating lines he pulled. The different size drums provided the flyman with leverage. The counterweight travels the same distance as the batten because its line and the loft lines are on the same drum.
The loft lines fan out from the drum to the loft blocks over which they roll and then descend to the batten. Lines G and H come off the drum toward offstage, one coming off clockwise, the other counterclockwise. Each goes to a block and down to the fly rail. The line descends offstage of the ladders to the second fly gallery where it appears to rub against the support beam on the offstage side. Then it rubs against the cleat rail on the offstage side to pass onstage of the ankle rail from which it rises to the operator's hands. It is presumed that while not being used, the operating line would be tied off at the cleat.
Moynet tells us that the counterweighting of the line set could vary in any one of three ways: the line set could be piece heavy, arbor heavy, or balanced. One could easily suppose that the decision of which counterweighting to use would depend on the main action of a given piece.
Returning to the flying bridges, it's curious why there are so many. It seems that providing cross-stage access and reaching fouled line sets is not sufficient justification. Perhaps the bridges were also used to trim the line sets.
The table above is derived from takeoffs of Moynet's drawing, figure 3. The batten length is assumed to be 14.5 meters (47.57 feet) long. Travel distance is assumed to be 22 meters (72.18 feet). Note: these dimensions were estimated by transferring a digital copy of Moynet's drawing to a CAD program and then scaling it.
Information from rope manufacturers tells us that rope made from natural fibers can vary in length by eight to ten percent depending on atmospheric humidity levels. Using those variables, we can calculate the variance in the lengths of the five loft lines because of humidity changes.
The deflection in the batten from a dry day to a rainy day could be drastic. As shown in the table, the long loft line could change in length by as much as 22 inches. Scalloping of the drops would be severe, rendering the scenery unusable without trimming. Fouling of the line sets would have been inevitable.
Flying bridges, then, especially the raised flying bridge at the third bridge, would allow four stagehands to go to the battens and, working together, trim the batten quickly and easily.
R.W. (Rick) Boychuk writes about the world of stage rigging. He started university to study history, but took a drama class and become hooked. During a forty-year career in theatre, however, he never stopped reading history. His book The History of Counterweight Rigging is on schedule for launch at the USITT Conference & Stage Expo in March 2015.
Loft Line Drum to Loft Block to Total Lengths Loft Block Low Trim Length meters feet meters feet meters Long L 8.6 28.2 22.0 72.2 30.6 Center Long CL 5.5 17.9 22.0 72.2 27.5 Center C 2.7 8.7 22.0 72.2 24.7 Center Short CS 1.6 5.2 22.0 72.2 23.6 Short S 4.6 15.1 22.0 72.2 26.6 Loft Line Total 8% of Variance Lengths Length Total Length from CS line feet meters feet mm inches Long L 100.4 2.4 8.0 560.6 22.1 Center Long CL 90.1 2.2 7.2 309.3 12.2 Center C 80.9 2.0 6.5 85.4 3.4 Center Short CS 77.4 1.9 6.2 - - Short S 87.2 2.1 7.0 239.8 9.4