Chief Custodial Officer Neil Beales said he was proud his staff who "responded bravely and professionally" to resolve several incidents recently, on one occasion saving a prisoner's life.
A remand prisoner entered custody and was placed in the Intervention Support Unit on Friday due to significant concerns for his mental wellbeing, Beales said.
"While being placed into a cell he became very aggressive and staff worked hard to de-escalate his behaviour, however pepper spray was used.
"On Sunday, staff were required to intervene to save the prisoner's life after he made multiple serious attempts to harm himself."
Emergency services were called and the prisoner was required to be restrained.
He was sedated by ambulance staff before being escorted to hospital.
"He remains in hospital and we are working with forensic mental health services to ensure that he receives the care that he needs."
Beales said none of these incidents were linked and prisoners involved in the violent altercations would be held accountable and charged with misconduct.
The spate of violent altercations included one prisoner punching another prisoner on Friday, which was caught on camera.
While on Sunday, two prisoners had to be separated and moved after being caught fighting.
"We have a zero tolerance for violence policy, and any violence or assaults against other prisoners or staff is not tolerated in prisons," Beales said.
"Their charges will be heard by a hearing adjudicator or by a visiting justice.
"If found guilty, they can be sanctioned with a loss of privileges such access to hobbies or telephone calls or visits in excess of minimum entitlement, forfeiture of earnings, or cell confinement.
"Prisoner-on-staff assaults have also been referred to police."
More than 75 per cent of the prison population have convictions for violence.
"We are constantly working to ensure our prisons provide the safest environment possible for staff and prisoners," Beales said.
"We have invested significantly in training and tools to keep our people safe.
"This includes tactical skills, such as de-escalation, through to the introduction of stab-resistant body armour, on-body cameras and the expanded use of pepper spray."
