Copyright resides with the residual holder, no reproduction without permission.
Thanks to Peter Poole for making these site plans of Pebble Mill available, and for adding the following information:
The plans show the patch panel points around the Pebble Mill building. These boxes were fitted with camera connection sockets, microphone sockets, audio tie-lines and mains power sockets. The outside boxes were fitted with heaters to prevent corrosion of the sockets. All the audio circuits appeared on the north riser jack field. They could then be connected to any studio using a double ender. In the audio unit the plans were used in pre-production planning. A rigging form would be completed showing the studio microphone setup. It would show all the cable connections from the studio floor to the mixer jack field. This is a simplified description. Normally the audio set up would be more complex.