What were the three stages of Sir Walter Crofton’s Irish prison system?

Sir Walter Crofton’s Irish system, developed in the 1850s, was a pioneering penal method that emphasized rehabilitation through training and performance. The system consisted of three distinct stages:12

• Solitary Confinement: The initial phase of the sentence was served in isolation.12
• Congregate Work: Prisoners moved to a phase of group labor, where they earned credits, or "marks," based on their industry and good behavior to advance through higher levels.12
• Intermediate Prisons: In the final stage, prisoners were placed in facilities with minimal supervision. This allowed them to demonstrate their dependability and employability in the outside world before their eventual release.12

Following these stages, release was conditional, often involving "tickets of leave" and ongoing supervision to ensure continued good conduct. This approach significantly influenced the development of modern parole and reformatory practices.12