A young offender institution (YOI) in Kent was found by inspectors to be in a state of “considerable concern”, with staff being unable to keep children safe.

Boys at HMYOI Cookham Wood in Borstal, near Rochester, are reportedly held in solitary confinement for “days on end” and 228 weapons made by children were found on the premises.

At the time of inspection there were 77 boys ranging from those on remand to some serving long, indeterminate sentences including life.

They were being overseen by around 360 staff – including 24 senior leaders.

The young offender facility is capable of holding 120 boys aged 15 to 17, although some are 18.

Nearly a quarter of boys in the YOI said they felt unsafe.

The report by His Majesty’s Inspectorate of Prisons stated: “This was perhaps unsurprising in view of the prevalence of delinquent behaviour and the number of weapons found in the months leading up to the inspection.”

One child told the inspector: “I have been stabbed here and brutally assaulted and been punished for being the victim because Gov couldn’t prove who started it. The violence here is horrific, there are weapons everywhere.”

The report also said the diffidence and lack of confidence observed among staff in their dealings with young people suggested some of them may also feel unsafe.

Inspectors witnessed repeated examples of intimidating and threatening behaviour by children towards staff, including insulting or pushing past them, which went unaddressed.

Staff had extremely low expectations of those in their care, and there seemed to be an acceptance of poor standards.

The report stated some staff members seemed to have “given up” and did not wear the correct uniform to work.

Leaders were reported to have introduced extensive instructions where boys known to be in conflict had to be kept apart.

At the time of inspection, 90% of boys were being kept away from other prisoners – this resulted in nearly 600 separate instructions.

The report stated: “This overwhelmed any meaningful regime and dominated the experience of staff and children alike.”

It meant access to education and other activities was determined by which children could safely mix instead of individual needs or abilities being taken into account.

Levels of violence were high and some boys spent “days on end languishing in their cells” in response to incidents.

The boys would be held in solitary confinement for extended periods and most had hardly any meaningful human interaction during this time.

Other children were separated for their own protection. Inspectors met two boys who had been subjected to solitary confinement for more than 100 days because staff were unable to guarantee their safety.

One child had been separated for nearly six weeks and the regime he experienced was rarely recorded, although the evidence seen suggested he only had time in the open air on one-third of the days that he was separated.

Separated children received an inadequate regime, and the most consistent element of a child’s day was a 30-minute period of exercise but on many occasions even this was not delivered.

Most separated children did not receive any education.

The report continued: “There seemed to be no imagination, creativity, or plan for how to promote good behaviour with ineffective incentives on offer. Only on the small Cedar unit, with the possibility of temporary release for a few, were children being motivated to behave.”

As a result, solitary confinement became normalised and many were locked in their cells for 23.5 hours a day – some did not come out for “days on end”.

Evidence of the deterioration of Cookham Wood was also observed in the physical conditions of the YOI.

Living units were dirty, important equipment was broken and there was graffiti.

The safety team was also under-resourced.

HM chief inspector of prisons, Charlie Taylor said: “Cookham Wood holds some of the most challenging yet vulnerable children in the criminal justice system.

“Staff should be supporting them in learning how to manage their behaviour and deal with conflict so that violence is reduced within the YOI, and they are less likely to reoffend on release.

“Instead, we found boys locked in their cells overseen by demoralised, frightened staff while leaders stayed out of sight in their offices.

“Perhaps unsurprisingly, staff spoke openly of how little confidence they had in the leadership.

“We were surprised and concerned to hear that, since the new governor had been appointed, no senior leader from the Youth Custody Service had been to see for themselves the failings at Cookham Wood.

“These findings would be deeply troubling in any prison, but given that Cookham Wood holds children, they were completely unacceptable.

“As a result, I had no choice but to write to the Secretary of State immediately after the inspection and invoke the urgent notification process.”

The report notes there will need to be urgent, concerted and long-term commitment from leaders at the YOI and from the Youth Custody Service to improve standards at Cookham Wood and make it an acceptable place to hold children.

Andrea Coomber KC, chief executive of the Howard League for Penal Reform, said: “This is a damning report that sets out in shocking detail why prison is no place for a child. How can boys hope to thrive in an environment where conditions are filthy, equipment is broken, education is virtually non-existent, staff are demoralised and violence is rife?

“Worst of all in this long litany of failures is the normalisation of solitary confinement, to the point where many children are spending 23-and-a-half hours each day locked inside their cells.

“This is particularly concerning in a prison where more than half the boys are on remand, awaiting trial or sentence, and we know from the Howard League advice line that there are children in other prisons being held in similar conditions.

“The Howard League has warned for many years that Cookham Wood is unsafe and totally unfit for children. This is the latest in a long line of devastating reports, and probably the worst yet. In a jail without hope, it seems that even the staff have given up.

“What more evidence do ministers require to close this prison and ensure that boys are given the attention, care and support they need?”