Interesting Iains, thank you for those links.
My prison visiting experiences were thirty years ago, and of course I'm a bit out of date with my information.

In my day, if a prisoner was still recalcitrant after a period 'down the Seg' he was moved to another prison and put on a wing there.
This is why I visited in several prisons to keep in touch with individuals who were always being shipped out in a 'sweat box' (prison van) to some other place.

I visited in:-

HMP Wayland
HMP Norwich
HMP Blundeston
HMP Highpoint
HMP The Mount
HMP Wormwood Scrubs
HMP Hollesley Bay
HMP Parkhurst