The first significant expansion of the prison buildings occurred in 1858 with the construction of B Division. Built in the centre of the prison with 123 cells and, in the 19th century, designed to hold 300 prisoners. A new wing was added in 1872 with 36 cells, guard accommodation and a wall separating it from the rest of the prison, with 37 more cells added in 1878. By 1880 the accommodation was seen as insufficient for the 280 prisoners then held, with up to three per cell and eighteen per dormitory room. A "T" shaped building was constructed in 1884 with 96 cells over three floors, and the walled area expanded. The building included a chapel, offices and three dark underground cells used for solitary confinement. Known as A Division, it was built by prisoners at the jail as part of their enforced labour.