Oakhill young offenders’ centre is suffering a lack of adequate control with surging levels of violence, vandalism and secret weapons.
A damning report this week highlighted serious concerns and called for urgent action to be taken.
The report shows there were 300 assaults on staff and detainees between March and August this year.
“Inspectors saw occasions when poor, often intimidating behaviour such as shouting, swearing and kicking property went unchallenged,” it states.
Combined with an “inconsistent” application of rules and incentives, this undermines relationships and leaves young people “vulnerable”, it adds.
Oakhill, run by private security company G4S, is designed to take 80 boys aged between 13 and 16.
At the time of the inspection, which was carried out jointly by Ofsted and the Care Quality Commission, the centre was close to maximum capacity.
Inspectors, who rated the centre overall as inadequate, said they found “no evidence that staff can adequately care and control this volume of young people”.
It refers to some of the youngsters carrying improvised weapons because they do not feel safe.
“This inhibits some staff from intervening because of the fear of a weapon, and this in turn reinforces the view of young people that staff cannot protect them,” states the report.
Inspectors also found Oakhill’s communal areas were covered in graffiti and some of the young people had decorated their bedrooms with “inappropriate” drawings relating to violence.
It said: “There is considerable graffiti in the communal areas and the bedrooms, some of which is gang-related. There is no evidence of this being challenged or addressed by staff... too many staff do not model an adequate standard of care or respect for the centre, so it is unsurprising that the young people follow suit.”
In March an officer was left fighting for his life with serious head injuries after an alleged attack by a group of young detainees on Oakhill’s football pitch.
The officer, who was only 21, was in a coma for weeks.
G4S bosses say they are now taking a number of urgent actions to address concerns raised in the report.
Lisette Saunders, Oakhill’s new interim director, said: “We take these findings very seriously. In the report, Ofsted recognised that senior managers at Oakhill know what is required to bring the centre up to acceptable standards.”
She added: “This year the team at Oakhill has made a number of changes, restructuring the workforce to provide better support for young people and frontline staff and greater management oversight and accountability.”