THERE was absolute bedlam. A banging, crashing, hammering racket so loud it felt like walking into the engine room of a battleship going at top speed.
There was no question of conversation, you had to shout into the ear of the person next to you to be heard.
The corridors and stairwells, and the mesh strung across the cell block at each floor level, were strewn with rubbish - newspapers, clothes, shoes, muck of one sort and another. The IRA inmates in Portlaoise Prison are in the middle of a protest.
The noise yesterday afternoon was to attract the attention of the media to the protest, which began three weeks ago after one prisoner was refused leave to attend his mother's funeral.
The IRA men knew when reporters would arrive in their cell block and were hammering as loudly as they could on cell doors. Other republican and "ordinary" prisoners in the block joined in.
Prison officers stood around shaking their heads, rolling their eyes to heaven.
"Their argument isn't with us, it's with the Department of Justice so it doesn't really affect us," said one, but another acknowledged that if the racket were to go on all the time - as used to happen during the frequent disturbances of the 1970s and 1980s - it would be hard for officers to leave the building without imagining they were going deaf or mad.
Portlaoise Prison is the highest-security jail in the State, and the extra measures are obvious from the moment you walk in.
Most prisons have two or three gates between the inner compound and the outside. Portlaoise has eight There are three more at the entrances to cell blocks, and others in the corridors and landings.
A prisoner in his cell is about 15 locked doors and gates away from freedom.
All visitors are searched and are required to leave items such as keys and red-headed matches (sulphur can be used in explosive devices) at the front gate. Prison officers even conduct "rubdown" searches of their colleagues.
There are two cell blocks. Block E is the separation block, where the various groupings of "subversives" live. It has four floors from ground level.
The top two corridors are for IRA inmates, the second floor is for INLA, IRSP, Republican Sinn Fein, Continuity Army Council and assorted republicans. The ground floor is mainly Dublin "gangland" criminals.
In the basement is a handful of prisoners, some of whom want to be separate from the rest. These include Dessie O'Hare, the kidnapper of Dublin dentist John O'Grady and one of the prisoners involved in the Mountjoy siege. Reporters were not allowed to meet any prisoners in Block E.
Block D is for "ordinary criminals," and also has a separation unit where four others from the Mountjoy siege are under a special disciplinary regime, denied privileges such as visits and phone calls until March 9th.
The republican prisoners always refuse to work - and so light maintenance and cleaning is carried out by the "ordinary criminals" of Block D. They earn 50 per cent remission on their sentences for coming to Portlaoise and doing the jobs the republicans will not do.
Assistant Governor Paddy O'Keeffe, who conducted yesterday's open day for the media, explained that the segregation in Block E meant not just separate corridors for the various groupings, but different times for all activities such as classes and recreation periods.
"We have to do everything four times," he said. The segregation is demanded by the prisoners, and each grouping has a leader who deals with senior staff at the jail.
Should prisoners be allowed to dictate their conditions in this way?
"We're pragmatic operators here, and you can't argue against pragmatism," says Mr O'Keeffe. He adds that the prison service is obliged to provide safe custody for inmates, and safety could not be guaranteed if some of the groups were allowed to mix.
"Sure they'd kill each other," said another officer later.
The republican prisoners have their own discipline system. Officially no one knows the details, they only know that it works. No IRA prisoner given temporary release, for example, has failed to return to the jail.
Portlaoise has 162 prisoners, of which loo (including 40 IRA inmates and 38 from Dublin crime gangs) are in Block E (blocks A to C are long demolished). There are 377 prison staff, and an undisclosed number of soldiers on rooftop posts and watchtowers.
Portlaoise is the only prison with an Army presence. "It really works," said one officer. "This is the only jail where a prisoner knows that if he gets out of his cell block, there'll be somebody pointing a gun at him."
There have been no escapes in 22 years, although there have been a few elaborate attempts. The high-security measures also mean drugs and other contraband rarely get into the prison, according to Mr O'Keeffe. The greatest need is for more work spaces and a modern building to replace Block D, which dates from the last century.
It is not known how long the current protest will last. According to Mr O'Keeffe, it does not affect the running of the prison.
The only obvious difference is that Block E looks like a rubbish tip. The Block D prisoners will not clean it up, nor will prison staff.
The IRA prisoners are responsible for it, according to Mr O'Keeffe. "They're putting it there and when the protest ends they'll clean it," he says.