Drafting for the Theatre

20. Levels—Both Stationary and Rolling

257 20.1 Holding It All Up Flat frames such as those discussed in the previous chapter are designed to simulate interior and exterior walls and are rarely called on to support much weight other than their own. Standard flat frames use construction materials oriented in the face direction, making them essentially “two-dimensional” objects. On the other hand, weight-bearing structures such as platforms, stairs, wagons, and stud walls rotate these framing members 90°, using them in the “on-edge” position (fig. 20.1). This rotation increases the material’s moment of inertia (stiffness), resulting in an increase of the material’s structural capacity. since this text is devoted to drafting, rather than engineering principles. So while the drafter will be introduced to a few basic engineering issues, the focus must remain on how these concepts are to be communicated in shop drawings . These remarks are focused on the nature and extent of the details required to produce a drawing useful to scenic studio personnel. The drafter, although normally not the person who will build the unit, must fully understand the basic principles behind such construction in order to produce useful drawings. 20.2 “Hollywood” or “TV” Flats and Stud Walls Board lumber is significantly stiffer when placed “on-edge” than when used in the face direction. This increased stiffness is the engineering principle behind the construction of a Hollywood/TV style flat (fig. 20.2). As the name indicates, this style of flat is utilized extensively in the television and film industries and is characterized by its lightweight, rigid frame and rapid construction. Placing the frame “on-edge” eliminates the need for the addition of stiffeners , making the unit ideal for situations requiring hard-covering applications. 20. Levels—Both Stationary and Rolling Numerous materials with potential structural properties can be found in the average scenic studio, and consequently, a wide range of alternative construction techniques for weight-bearing structures has evolved. For most theatre technicians, there is no single preferred technique, no “one right answer,” but rather a variety of alternate systems, each having advantages and disadvantages. Choice of technique is based on the unit’s desired appearance , use, and handling. Examining all these numerous alternatives here would be impossible and inappropriate, 20.1 Platforms, stairs, wagons, and stud walls 20.2 A Hollywood or TV flat 258 The type of joinery most commonly used in “on-edge” construction involves end-toface butt joints. Because no gusset fastening is required, it is standard practice to draw front elevation shop drawings of these units. This procedure provides the carpenter a more comprehensible visualization of the finished unit than is provided by rear elevations. If “onedge ” units are drawn using rear elevations, the drafter must clearly label the drawings as such. Hollywood-style flats are more difficult to draw by hand than standard frames, since the¾″ dimension of the frame is very narrow in½″ = 1′-0″ scale. Framing principles remain the same, except that framing members must be positioned so as to tightly secure the perimeter of the 4′×8′ modular sheets used to cover them. Should the unit be used structurally, the framing pattern has a vertical rather than the horizontal orientation shown in figure 20.2. Exterior plywood gussets and internal diagonal braces may be used to keep the walls more square, although most frequently they are omitted since the panel material serves the same purpose. Typical specifications include the frame material (usually 1×3 or 1×4), fasteners , covering, and joinery details. More often than not, a Hollywood-style flat is larger than a single 4′×8′ hard cover. Where joints occur the drafter must provide sufficient framing to firmly secure the edges of the hard covering. Even with this attention to good fastening technique, sheet products create seams, so many of these frames are covered a second time with a muslin cover, sewn into a single piece if the unit is wider than the standard muslin available. Common practice is to stretch and wrap the fabric around the edges of the unit and staple it to the rear edge (preferable ) or the side faces. If desired, the fabric can be stapled and glued directly to the hard covering, identical to standard flat covering methods, although using this approach is less likely to diminish the panel seam lines. Hard-cover seams will be less of a problem if the drafter provides a sufficiently wide surface area in the framing on which to abut the sheet products. Two...