Normally made out of the salt encrusted oak of former naval vessels ensuring that the pil beam is solid and free from chafing.
It was thought to have originated in the early 16th century in the South west of England and was first mentioned in Brother Callicot's ecclesiastical tome 'Under ye leather Hud'.
A working example is still kept in operation in Wormwood scrubs prison. This is required by law as some present day statutes still have the Pil beam as a condition awarded in court for minor offences such as home taping from the radio.
'Hang on, things are livening up, the Pil beam is being wheeled out'.
'Hand me another C45, I am going to tape the Steve Wright show off the radio'
'You know you can end up over a Pil beam for something like that'.