HS 100
The HS100 video disc was launched in the States in March 1967, being used in the coverage of the "World Series of Skiing" at Vail, Colorado. Ours arrived in 1968 and was installed in the 'viewing room' that would later become VT17. The installation was designed so that the machine and its desk could be taken out on location - in fact it made only one outing and that was to Wimbledon in the summer of 1969.
Later on a set of spares (a very large set of spares) was purchased which amounted to another machine! It can be seen in this picture, (left) by Geoff Higgs, sited to the left of the main crate.

Nick Bayston became 'Nick the disc' and cared for it for many years.(Click here for an Ariel feature on Nick) One of the new SREs (Senior Recording Engineers) was attached to Nick in rotation and together they provided slow motion facilites to, mostly, sports programmes. The disc was used in drama for special effects and in "Life at Stake - Apollo 13" it was used to create scenes of weightlessness in the Lunar Module.
For Sports programmes it was operated by a Sports PA (later Sports AP) on the grounds that the studio director could swear at them without (much) risk of their walking out of the room!

The disc, which weighed 2.3kg and rotated at 3000rpm, was mechanically quite sensitive, especially to vibration - as the heads 'flew' microns off the surface of the two rotating discs. When head met disc it was normally the end of both (see below)

Disc scratch

The two pictures above show HS100 disc 011484 resting on my back lawn (!). This disk failed in February 1972 while holding the opening titles for the Winter Olympics. Just ten seconds to TX there was a loud 'whistling' sound which was the head touching the disc surface and making the groove seen in the right hand picture. The photograph below, taken during rehearsal, shows the actual shot we were holding when the disc failed. The damage was to the rhodium top coating, which was above a thin layer of nickel-cobalt and then copper, all on a 16 inch diameter aluminium disc.

Winter Olympics
The head assemblies were delicate, lightweight items. As a result of the high rotational speed they actually flew a few microns above the disc surface. They (four of them, one above and one below each of the two discs) were moved along tracks by stepper motors to cover the entire dic surface. John Sedgwick took these pictures of a video disc head that has survived.

The delicate assembly required careful handling during cleaning - it was very easy to damage the connectors let alone the head itself.
The picture above clearly shows the pads which stop the head from damaging the disc surface when it 'lands' on power-down.

Recently I have also been given one of the original HS100 brochures - thanks to Bob Oakley - follow the Brochure link for a scan of it.