This picture shows a wider view of the Video Disc room. The window on the left looks out to the VT9&10 complex operations desk.
The DANGER barrier is there to prevent head and disc damage caused by people bumpng into the machine. Routine maintenance involved removed the discs and heads once a week (or more often), cleaning them with isopropyl alcohol and then reassembling them. The whole disc assembly was fastened to the drive motor shaft by a large nut which was tightened down to the required tension using Nick's car torque wrench.
Ampex decided there should be a better way as a Swiss (TSS?) company had a disc 'come off', bending the head stepper motor carriages up at 90 degrees! So they retro fitted an over centre clamp - all you had to do was tighted the clamp down and then flick the clamp lock over to hold everything tight.
I had the privelege (?) of first powering up after the modification. It was a 'Floodlit Rugby' match and, I think, John Philips was the PA. As the machine ran up to speed, there was a 'clink' from the new clamp - which had come undone......we both dived under the desk, I hit the breaker on the way down! When everything had stopped, there was a deep groove in the perspex lid - which was luckily in place - where the clamp had spun round at high speed. A modification came out the next day!