Old and new flying at the National- part 2, the new

The new system control desk is a lot more intuitive than the old and uses 2D & 3D graphics to great effect. It has two physical controllers but virtually there are six and a paging arrangement means that the flyman can quickly take control of any or all playback cues in order to react to subtle timing variations in a performance. The large bar-like device on the front left edge is a dead man’s handle arrangement where removal of rotational pressure will cause a smooth cessation of all movement. (The red emergency stop button does what it says on the tin).

The ability to profile movement speed makes the Leeds Grand system look soulless and sterile when doing flying cues, especially the house tabs.

Meanwhile, up on the grid, something that looks somewhat like a floor polisher is able to be positioned pretty much anywhere. Large yellow spreader plates are used where the lifting weight is going to be over the spot grid limit. The placement of the units was demonstrated for us and the biggest nuisance is in the tidying up of the excess cable from the DC controllers.


Old and new flying at the National- part 1, the old

I had a very interesting technical visit to the National Theatre last Tuesday morning, including a visit to the grid 27.5m above the Olivier stage.

The Olivier is an open stage in an ampitheatre style and the fly tower is more-or-less hexagonal in shape. It was recognised back in the early 1970s that standard flying bars parallel to the proscenium was not appropriate for a venue without a proscenium, so instead, a very flexible point hoist system was installed. There were 170 hooks which can be moved left or right from their home position, connected via a switching matrix to 36 variable frequency controller units known as cyco-converters. It was all controlled via a PDP 11 Mini computer and a custom control desk. The system was clever enough to move any of the hooks at any individual speed in either direction, up to the limit of 35 moving at any one moment (One was a a spare).

The system worked very well for the first three decades but accelerated component failures in recent years now mean that only six controllers work and lots of the winches are unservicable. On that basis, the old system is now relegated to rigging and static flying. Looking at an article written in 1979, it seems that the current control desk is not the original one so there has been an interface refresh at some point.

The theatre has now installed a phase 1 upgrade consisting of 30+ new hauling units, more about the new stuff next time.