Haha Phil, after telling my mum about those rides, she remembers them like they were yesterday. XD
The witches hat was basically a circle with a wooden seat, bars came up into a cone shape that you could hold on to and there was a central bar in the middle of the circle to support the ride.
Once everybody got on, everybody rocked back and forth to start it spinning and the in-and-out movement around the central bar.
You pretty much had to hold on for dear life, as if you slipped into the middle, you got crushed between the seats and the central bar There was space underneath, but if you fell off backwards you would not have time to get low, because it would throw you off with force.:shock:
Also, as there was pretty much no way to stop it, the only way to get off was to jump from the seat onto the concrete below. XD
Also in your second photo, in the back right you can see the bench with handles on. That's a very small version in the photo, but with larger versions about 10-20 people got on, and started swinging from side to side. You could easily get more-than-vertical with enough people, and you only had the tiny handle to hold on to to stop yourself falling off onto the concrete below.
Sounds like great fun... XD
Edit: Found a photo of the Witch's Hat thing: