The prison is located in a largely rural area close to the village of Ranby in Nottinghamshire, about one mile from Ranby village which lies 3 miles from Retford and 6 miles from Worksop on the A620. Since opening as a prison in 1972, Ranby has regularly had its capacity increased, most recently in 2008 when further acommodation was built. Workshops,a new health care building, kitchen, library and education facilities were added. In May 2016, Ranby became one of six early adopter sites for autonomy, enabling the director of the East Midlands Prison Group to make their own business and financial decisions independently of the wider prison estate. HMP Ranby is now part of the North Midlands Prison Group.
The prison opened in 1971 on the site of a former army camp. It has seen a steady expansion from 2004 with the development of modern house blocks. The most recent expansion was C wing, which opened in 2008. Workshops, a new kitchen, a library and education facilities have been added as part of previous expansions. The recent expansion of the prison has enabled a larger number and variety of work places, including the conversion of the former clothing exchange store and original C wing into the health care building and performance suite.
The acting #1 governor is Andy Sleight, in charge since December 2021, and the prison can accommodate up to 1038 prisoners. HMP Granby is managed by HMPS and is part of the North Midlands group of prisons.
Short description of residential units
- House block 1: 248 prisoners.
- North: induction wing;
- South: prisoners with 12 weeks or less to serve
- House block 2: 244 prisoners.
- North: a general wing;
- South: the drug intervention and drug recovery unit
- House block 3: 237 prisoners with various sentences
- House block 4: 60 prisoners; the incentivised drug-free living wing
- House block 5: 192 prisoners with various sentences; eight spurs with 24 cells on each spur
- House blocks 6: 60 prisoners with various sentences
- House Block 7: 60 prisoners with various sentences