The 13-storey building that defied the efforts of international explosives experts yesterday was finally felled last night after a crane with a wrecking ball finished the job the explosives couldn't do.
The task had been expected to take another 24 to 48 hours. But after preparatory work with a "long-reach" crane further weakened the building - crumpled but still standing after the controlled explosion - the wrecking ball reduced it to a pile of debris at 9.40 p.m.
The demolition firm which had won the tender to demolish the former nurses' home on the grounds of St Vincent's Hospital in Dublin said the explosion "had gone to plan" and said it had used the "minimum" amount of explosives it thought necessary.
"We were under pressure to minimise the amount of explosives we used because this is a hospital site in a residential area," said Mr Darren Palin, commercial director of the Yorkshire-based Controlled Demolition Group.
Mr Brian Doran, of Downes Meehan and Robson architects, said he was "very surprised" when he heard that the demolition company had been unable to raze his firm's building yesterday.
Technicians had spent three days wiring the building with explosive charges and two months pre-weakening it, drilling more than 800 holes in it. However, the concrete structure was not for collapsing.
Following a 10-second countdown and two blasts in rapid succession, the building front cracked and partially collapsed inwards, but it did not fall to the ground.
One gable end remained almost intact while the middle of the building sagged and it was left leaning to one side.
Mr Chris Robson, son of Mr Harry Robson, co-founder of the designing firm, said his father would find it ironic that the building was so resistant to demolition, given that it was designed and built "on a very tight budget".
"I don't think it was one of the buildings they were most proud of," he said.
According to Mr Doran, the firm had "had mixed feelings about it. We felt putting a tower block there was not perhaps the best idea."
Mr Palin said the building was a lot stronger than had been anticipated. "The gable ends and lift shaft have kept the building intact," he said.
"The project has now changed from an explosives demolition project to a traditional demolition."
He said the company, which has been bringing down highrise structures all over the world for over 20 years, had never had a failure like this. "Well done to whoever designed and built it," he said.
However, CDG did have a similar experience in 1997 in Scotland, when its efforts to level an industrial crane did not go according to plan.
Having wired it with controlled explosives at its Clydeside site, the crane remained its full 287 ft high after the blast, albeit a different shape.
A spokeswoman for the company said the Glasgow incident was different because it involved a crane.
Before yesterday' planned implosion, the chief executive of the hospital, Mr Nicolas C. Jermyn, said the project would mark a "fundamental milestone in the realisation of the development plan for the hospital". The razing of the former nurses' home is part of a £170 million project to build a new main hospital building, which will be linked to the existing main building by two link corridors. After the blast, Mr Jermyn said the failure to level the building using controlled explosives would not mean further expense to the hospital.
Completing the job was CDG's concern, a spokesman said. The hospital reopened as planned at noon yesterday, although traffic remained restricted into and around the hospital until the demolition was completed. It refused to say how much it was paying the demolition firm.
CDG is one of the companies tendering for the demolition of Ballymun flats, due to begin early this year.
