"Marrying the three sisters", they called it. For minor infringements, prisoners could receive 25 lashes, for major ones, 50.

Don't read any further if you have a delicate constitution.

Under the age of 16, males could be caned or birched. Over 16, they could be flogged. Female prisoners were not beaten.

Prisoners who were to be flogged were tied into this frame face down. Their shirts were taken off. A wide leather belt was put around their waist to protect their kidneys, and a leather collar was added to prevent their throat being cut.

The whip, a cat-o-nine tails, was soaked in salt water to minimise infection (and probably maximise the sting, but that's saying the quiet bit out loud). Afterwards they were taken to the hospital to have salt rubbed into their back to minimise infection and promote healing. And to sting like hell, but again, quiet part, out loud.

The scars would never heal, though.

During the 1800s at least, the flagellator would often be another prisoner.

The triangle was last used in 1958 (at Pentridge prison; this one had closed by then) when two prisoners injured a guard in an escape attempt.