Conservation Management Plan
15. Stage Bridges 15.1 The standard layout of the English Wooden Stage relied upon two key elements, the “bridge” and the “cut”. The bridge was a large timber platform that could be raised and lowered between the substage, stage and sometimes above stage level to produce three-dimensional scenic effects. John Crallan’s axonometric illustration of a stage bridge mechanism demonstrates the principle upon which most bridges operated during the second half of the nineteenth century. Contained within the Citizens’ Theatre substage are three such structures, generally in good condition though in need of stabilisation and conservation. Nevertheless, they are remarkably complete and by far the best surviving examples in Scotland. 15.2 As with the Corsican Trap this kind of equipment was in response to the dramatic fashions and demands of the time, and enabled theatre managers to produce spectacular stage effects for pantomimes, sensation dramas and melodramas. The bridge platform, which stretched the full width of the proscenium opening was controlled from a timber windlass located on a mezzanine floor beneath the stage. A rope attached to this windlass was passed down into the cellar where it ran around a deflection pulley before being wound around the circumference of a large timber drum measuring approximately six feet in diameter. Two more ropes were wound onto the shaft, one of each side of the drum. These then passed to respective deflection pulleys mounted at each end of the bridge guides, eventually passing up and over a final set of deflection pulleys just below stage level, before being attached to the bridge platform. 15.3 This rigging system produced a mechanical advantage proportional to ratio between the circumference of the drum and the shaft. The operation of the bridge was also assisted by counterweights attached be ropes to each end of the platform. This allowed the stage carpenters to compensate for any particularly heavy scenery or large numbers of performers who had to be raised up to stage level. 15.4 The bridge platform was constructed to form a strong timber lattice capable of supporting significant weight. However in order to maintain the scenic illusion it was often necessary to “mask” this timber framework with scenery. This was achieved by using the “cuts” which were regularly positioned inbetween the bridges on the stage. A typical layout, and one illustrated by Sachs, was a sequence of a bridge and two cuts repeated at least three times as demonstrated by the stage at the Citizens’ Theatre.
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