Boys over 16 years who are too difficult to be handled in a certified school or have misbehaved there are sent to a : -

Borstals: Boys over 16 years who are too difficult to be handled in a certified school or have misbehaved there, are sent to a Borstal. Borstal, as an institution, falls between a certified school and an adult prison.  A borstal sentence is usually for 3 years, and is regarded as a method of training and reformation.