A Dublin man arrested on explosives charges in the run-up to the State visit of Prince Charles last year has been jailed for five and a half years by the Special Criminal Court.

The court previously heard evidence that gardai found explosive device components in the man’s locker at Maynooth University.

Last month, Donal O’Coisdealbha (25), of Abbeyfield, Killester in Dublin 5 pleaded guilty to membership of an unlawful organisation styling itself the Irish Republican Army, otherwise Oglaigh na hÉireann otherwise the IRA within the State on May 13th, 2015.

Sentencing O’Coisdealbha ton Tuesday , Ms Justice Isobel Kennedy, presiding at the three-judge, non-jury court, said that the evidence against the man was “significant” and even “overwhelming”.

The court previously heard from Detective Inspector William Hanrahan, of the Special Detective Unit, that in the months leading up to the royal visit, in May, 2015, O’Coisdealbha and others were being kept under surveillance by gardaí.

In January 2015, O’Coisdealbha was observed at a pub, The Coachmans Inn, in Swords, meeting with “a particular individual” who has a conviction before the Special Criminal Court and who is suspected of having a significant role within the IRA.

Further meetings occurred between the two men in The Coachmans Inn in February, March, April and May of that year.

On May 9th, O Coisdealbha was seen in the company of two brothers driving to a house at Harbour Court in Courtown in Wexford.

During a subsequent search of the house, gardai found four improvised rockets, Semtex, a chord of cortex and two detonators.

A search was also conducted at O’Coisdealbha’s workplace at Maynooth University on May 13th. A a time and power unit (TPU) and a broken circuit board were found in a specific locker which only O Coisdealbha, who worked in biomedics, had access to.

A TPU had also been found in the Courttown house. When both TPUs were analysed, it transpired they fitted together.

O’Coisdealbha’s DNA profile was found on a pair of gloves in the Courttown house and also on an improvised explosive device found in a car at Mitchelstown in Navan.

Ms Justice Kennedy said that the court paid particular attention to the fact O’Coisdealbha used his intellect and educational skills to provide the TPU.

The court also heard evidence of audio recordings made by gardai of O’Coisdealbha and the other man.

They met on May 10th and plans to develop an artillery rocket were discussed.

The court heard that it was clear from that conversation that preparations were well advanced and the indication gardai had was that the event was to happen around May 19th, when Prince Charles was visiting the country.

There was a reference made that a timer was to be used with a 14 minute delay and the blame was to be given to a different organisation within the IRA.

Ms Justice Kennedy referred to a letter written by Maureen O’Sullivan TD, dated from July this year, which expressed some dismay as regards the length of time O’Coisdealbha had spent in custody.

The judge referred to a “puzzling” expression in Deputy O’Sullivan’s letter which said that nothing was to be gained by prolonging O’Coisdealbha’s period on remand.

The court could only surmise, she said, that the content in the testimony came about in circumstances where the writer was unaware of O’Coisdealbha’s decision to plead guilty.

Ms Justice Kennedy went on to say that among the aggravating factors was O’Coisdealbha’s use of his intellectual abilities and educational skills for nefarious ends.

Mitigating factors were his early plea of guilty, his lack of previous convictions, his remorse and his educational abilities

Having regard to the gravity of the offence, the judge said, the court considered seven years an appropriate sentence. Taking into account mitigating factors, the court reduced the sentence to five and half years in prison.

The sentence was backdated to May 30th last year.