The prisons watchdog has flagged up high levels of violence and severe drug problems at a large men's training jail.
HMP Northumberland recorded 142 violent incidents, including 29 assaults against staff, in the six months before an inspection this summer.
The overall tally compared with 60 registered at the previous assessment in 2014.
HM Inspectorate of Prisons (HMIP) said the prison suffered six self-inflicted deaths in the last three years, but few of the shortcomings identified by investigations had been addressed.
A survey of inmates found three in five (61%) said it was easy or very easy to obtain illicit drugs in the jail.
The inspection report said the positive rate from random mandatory drug testing between January and June 2017 was 17.37%.
With the inclusion of testing for new psychoactive substances - formerly known as legal highs - the percentage of prisoners testing positive increased to a third (33.9%).
The report praised 'excellent work' being carried out on a residential unit dedicated to older inmates.
A weekly club provided 'purposeful activities' for over 50s such as carpet bowls, speakers, quizzes and table games.
Mr Clarke said there was a 'very clear determination' on the part of the prison's leadership to make improvements, while a spokesman for HMP Northumberland said an action plan has been put into place since the summer inspection.
The spokesman added: "We are pleased the report recognises the on-going commitment from the prison leadership to make improvements, that the majority of prisoners report positive interactions with staff and that prisoners are developing good work skills and high achievement rates in education and vocational training qualifications.
“We continue to work hard to tackle drugs and violence, which are a challenge across the whole prison estate, and we have strengthened our violence reduction team, introduced more drug testing and secured funding for additional CCTV equipment. Also as a priority, we have significantly improved our public protection processes and are working more effectively with probation services."