IT WAS about three o'clock on the morning of Wednesday 31 March 1976 when the Cork to Dublin mail train emerged at last from the gloom. It was behind schedule.

'Frank' (as we shall call him) was positioned at a bridge over the railway track towards the Sallins side of Hazelhatch in north Kildare. He was carrying four flares, in case any might be defective. He fired one into the darkness above . . . a signal to other members of the 17-man gang farther down the line to put detonators on the track.

They did so, rapidly. The plan was that the train should stop beside fields where a Volkswagen van was parked to take away the haul.

Three detonators went off as the train passed over them.

Immediately it began to stop;

by regulation, the driver had to stop the train when he heard detonators. It was a signal of danger ahead.

When the train stopped it was boarded hastily by members of the gang. They were armed and wore balaclavas.

They were "very aggressive", Frank recalled. It was planned that way in rehearsal, for quickest results. No one was hurt.

No one was assaulted. The gang met "no real resistance".

Over the next minutes, 12 bags containing registered letters and old bank notes, which he valued at "close to £1,000,000", were thrown from the train to the fields below, where they were lifted into the blue Volkswagen van. It had been commandeered by gang members about four hours earlier from greengrocer (and New Zealander) Ray Reynolds in Palmerstown, Co Dublin.

'Disappeared into the night' The official estimate put on the haul by the authorities later was £221,000, an amount described then as the biggest ever taken in a robbery in the Republic. So large was the haul that the van had to be pushed out of the field by seven or eight of the gang members, he recalled. The entire operation took less than 25 minutes.

The only house near the scene had been commandeered by gang members about two hours earlier and its phone cut off. Living there were Conal and Marion O'Toole, their three children, and Marion's mother, none of whom was aware of what was happening or of what had been planned. There were three cars in the driveway of the O'Toole home. Two would be used by the gang.

When the Volkswagen van was pushed out of the field and drove off, other members of the gang followed. Frank took one of the O'Toole cars.

He recalled that one car drove in front of the Volkswagen van and one behind. Two garda patrol cars passed them, heading for the crime scene.

The van, unable to pull the weight, stalled at Captain's Hill, near Leixlip. Both cars emptied as gang members got out to push the van uphill. "It looked amateurish after such a professional operation, " Frank commented. Then the van "disappeared into the night", he said.

He assumed its contents would be going to IRA prisoners' dependants, but he didn't know.

"You did the job you were asked to do and then it was on to the next operation, " he said.

"I have no idea what happened to the money. It was handed over and that was not an issue with me. It could've been used to set up ten builders, when I look back. Anything could've happened [to it]."

Frank drove on to Templeogue in south Dublin where he had parked his own car the previous evening. He put the keys of the O'Toole car under its back bumper and left it there, and drove in his own car to the house where he was then staying in north Kildare.

He got word of their car's whereabouts to the O'Tooles "four or five days later", he said.

Guards 'gave me an alibi' He had been in bed "ten minutes" when two detectives from Dublin arrived at the house. It was about 6.45am. "I was their main suspect and they gave me an alibi, " he said.

He would tell them so later.

They had found him in bed.

Had they touched the bonnet of his car they would have felt it was warm. They did not.

In a raid on the (now) TD Tony Gregory's house in Dublin that morning, also in connection with the mail train robbery, he was saved from arrest when detectives found the bonnet of his car was cold.

Gregory was already by then a well-known political activist in Dublin city centre, a member of the Irish Republican Socialist Party, as were most of the other suspects arrested.

Gardai were correct in being suspicious of Frank's role in the robbery. For six weeks beforehand he had been involved in planning it. He had identified the train to be robbed and its schedules. He had bought a bike so he could do surveillance of the rail line in the north Kildare area to establish where the best place to mount the robbery would be, remoteness and accessibility being priorities. He chose the location.

It had been necessary to bring in "outsiders" to help the local IRA cell mount the operation. That cell, as with all such IRA cells, consisted of four. When an operation was to be mounted, instructions would come from headquarters to just one member of the cell; that way the flow of information could be controlled.

The robbery had been well rehearsed beforehand in sheds around north Kildare.

Every detail was anticipated and planned for, except the weight of the haul. To the best of Frank's knowledge, not one of the other 16 gang members was ever held or questioned in connection with the mail train robbery. Nor was he again, after being pulled from his bed by two detectives that morning. Besides, most of the other 16 "didn't have permanent addresses", he recalled.

"Being a volunteer was a bitch of a job. You were lucky to have a house to go to. A lot of the time you go around in wet clothes, with no proper meals, going from shed to shed. How often did you have a warm bath? How often did anyone put an arm around you and said they gave a f**k?

What kept you going was bravado or getting one over on the guards, whatever, " he remembered. "One thing the IRA could never allow happen was for a ceasefire to go on over ten days. Volunteers might get used to a normal life, a warm bed, money for the pub."

Frank had been active in IRA operations for 12 years and was on the run for short intervals during that period.

He had been arrested and remanded in custody many times, occasionally for things he didn't do, but was never charged or sentenced to a jail term. "Even in Green Street [Special Criminal Court] they had to have some sort of evidence, " he said.

He remains totally convinced that the authorities knew from very early on that neither Nicky Kelly nor any of the others charged in connection with the mail train robbery had anything to do with it.

"I can guarantee you, the state, the government, everyone with the slightest interest, knew Kelly didn't do it, and from the beginning knew it.

Why were they at my house [where he stayed that night; it was not his home] if they didn't?" he asked. "They knew only the IRA could have pulled something like that off." He added: "Kelly and the rest couldn't have robbed a chip van."

Besides, Frank told the gardai directly. About 15 months later he was arrested in connection with another IRA operation. He teased the detectives about not doing their job properly over the mail train robbery. He told them they had given him an alibi, where it was concerned, because they hadn't checked the bonnet of his car. He told them they should have done their police work better.

They were "embarrassed", he said. But he would never accuse the guards of being stupid. Some were "highly intelligent".

"They are like any organisation. Like the IRA. You meet every kind . . . the good, the bad bastard and everything in between, " he said.

Troubles 'were a mistake' In his 60s now, Frank is from rural Ireland. A fit man of medium build and stature, he drinks little and speaks in an intense, staccato style. He drinks alcohol on occasion but has no problem in dispatching coffee, cup after cup. "It never keeps me awake, " he said.

When we met in July 2006, he recalled the silence in his primary school classroom when his Old IRA teacher spoke of his own activities during the War of Independence.

But Frank insisted that no one but himself was responsible for his activities during the more recent Troubles, none of which, apart from the mail train robbery, he wished to discuss in any detail. He regrets it all.

"I gave too many years of my youth to it, " he said. All that came of it was that "it gave a lot of people reasons to visit graveyards". He now believes that, with the EU and normal population trends, the North "would have sorted itself out. The Troubles were a mistake."

He blamed "a lot of naivete" for ever getting involved.

"Reality comes with age, " he commented. Looking back, for instance, at Padraig Pearse's speeches, "he was a raving lunatic, wasn't he?"

However, Frank's views on Gerry Adams and Martin McGuinness are very different. He has "the greatest of respect" for both. They were "two incredible soldiers and two incredibly able politicians" whose "greatest achievement was to be able to secure the peace process to where it is without allowing the IRA to split. It has never been done before."

As for himself, Frank ended his activities with the IRA before the peace process began and has never been politically active. He doubts he would have been involved at all but for what he learned while in the US army during the 1960s. The Vietnam War was escalating and he was drafted.

"We were all trained for field intelligence with long-range reconnaissance patrols." At the time the casualty rate for such patrols in Vietnam was as high as 90%, he was told. He and others questioned what it was all for.

"Who gives a f**k for Vietnam?" they asked. He realised that he was "an Irish farmer going to kill Vietnamese farmers with whom I had far more in common". He refused to go to Vietnam and was honourably discharged. He believes that if he had not got that army training he "would never have got involved here".

Not that he was blaming the US army either. The responsibility lay with himself alone, he said.

It was from his US army training that Frank taught IRA members how to handle interrogations, he said. "You take control of the situation.

Refuse to answer questions.

Concentrate on a white spot on the wall and remember the fear is based on what you know they can do to you, not what they are doing to you, " he recalled.

He also said he introduced the cell system to the IRA, whereby no more than four in an area belonged to the organisation.

"It worked very, very effectively, " he said. "The four would know each other intimately. If something needed to be done in a particular area, headquarters would contact one member of the cell. That way it was very easy to find out what happened if anything went wrong. Very few did [go wrong] because of that."

There was a downside, however. "It was why supergrasses lasted such a long time, " he said. Because those involved knew each other so well there was no suspicion and there was an element of trust: "You didn't squeal on a buddy."

When an instruction came from headquarters, "you didn't ask why", he said. "You just got on with the job, and when it was done you waited for the next instruction."

Despite this, Frank insists he was never actually a member of the IRA. "I worked on my own. It's the reason I survived as long as I did. I was always independent, " he said.

However, he believes the IRA considered him a member.

He "disagreed entirely" with the IRA shooting RUC men in the North and indeed with the shooting of British soldiers there, believing the campaign should be targeted at those responsible in Britain. He blamed the British for starting it all in 1972, when internment was introduced in the North. In so doing they "declared war", he said. He believed they did so deliberately, so their soldiers could have training in that type of warfare "and republicans fell into the trap". Otherwise he believes the Troubles would not have happened at all.

Internment led to the IRA having more recruits than it could accommodate. Such was the chaos, he said, that the Provisional IRA was "a sad f**king bunch when we started".

He dismissed outright suggestions that Fianna Fail or Charles Haughey had any part in their creation. "Not at all.

They were created by the British army, " he said.

He had high praise for Haughey. "He was one of the greatest Irishmen we ever had." He had been "directly responsible for the peace process being started. Himself and Fr [Alec] Reid. They had been dealing with the IRA behind the scenes from the early '80s, " he said.

Frank's praise was not party-political. "The biggest [arms] dump in this country was on a Fine Gaeler's land, " he remembered as an example.

Such "everyday people took huge risks of their own free will", he said.

Subversive views Today Frank owns and runs the small service business he set up when he "retired" from active service with the IRA.

He reared his children to think for themselves, to be independent, and not to make his mistake, not to waste their youth as he believes he wasted his own. They are now young adults. His family is all to him, and particularly his wife, who stood by him through "the stupid years" when she suffered harassment because of his activities.

It is for the family's sake that he doesn't want his name used in this interview. He doesn't want them to be a focus of any attention it might provoke. The guards "know who I am", he said. He was not concerned that they would identify him.

Yet he retains many of his subversive views. He sees the gardai as "enemies of the state set up after the 1918 election".

He believes refining diesel along the border and smuggling there to be "patriotism" . . . not that he is involved in either, or has been, or benefited in any way financially from such, or from any IRA activities. And he defines a patriot as "a man who fights his government for his country".

As for Nicky Kelly and others charged in connection with the mail train robbery, he is dismissive. They were "pub talkers who talked too loud and too long".

He was direct and forthright, which is why he has been dubbed 'Frank'.

Taken from 'While Justice Slept: The True Story of Nicky Kelly and the Sallins Train Robbery' by Patsy McGarry (published by The Liffey Press, 16.95)