Guy Kendall, head of electronic systems at the National was responsible for finding a solution. The brief was simple: provide a new control system for the three lifts and the main stage wagon to enable synchronous motion.
"Once we had the brief from the designer we knew that the existing systems could not provide the functionality required,' explains Kendall. "So we contacted Stage Technologies with a seemingly impossible challenge. They had to work with equipment that while aged was still functional yet was never really intended to operate in the manner which was now expected - accurate tracking of three independent hydraulic platforms (scissor and jigger) and tight positioning of a 15m x 15m hydraulic wagon, all with 100% reliability for a show running in rep with no dark time.
"Our envelope of operation was so tight that a few centimeters out of alignment on the elevators would damage the set, or worse still block the stage for the remaining scenes causing a performance shutdown. The wagon had to track downstage 20m and stop within 10mm reliably on every single move."
Kendall's systems engineering team worked closely with Stage Technologies engineers as well as with one of the National's automation technicians, who helped to install the cable infrastructure early in the mornings before performances. Testing was carried out in the same fashion before handing back to the stage for matinées or voice work. An overnight period saw the commissioning of the wagon with perfect control and the three elevators followed a few days later with an accuracy of 5mm.
Training was provided for the Lyttelton operators, first at Stage Technologies London office and later in situ at the theatre. An Illusionist desk was provided for the duration of the show, along with eChameleon programming capability to allow dependable cue plotting for the lifts and wagon.
(Jim Evans)
