Queen's "Crown" lighting rig was used for the last two concerts of the A Day At The Races tour June 6-7 1977 at Earl's Court. The total cost was GBP 50000 and it was the very first mobile lighting rig. It weighed 2 tons.
The lights are the exact same as before but they were hung off the Crown and aligned straight across like the Sheer Heart Attack / A Night At The Opera rigs. The side and ceiling lights were run along the bottom of the Crown as shown in the pictures.
There was a very large screen or fabric material that shaped the top resembling a Crown lined with lights. The rig ascends at the start of the show revealing the stage, and descends at the end of the show covering the stage.