The homemade device, which contained shotgun powder, was “incomplete” as it did not have key components, including a detonator.
It was the fourth device discovered by gardaí in less than 24 hours. The other devices were viable pipe bombs and were found in or around Traveller halting sites in Finglas, north Dublin.
Garda sources said these devices are not linked to either the impending visits of Britain’s Queen Elizabeth or US President Barack Obama and suspect they are connected to Traveller feuds.
The dud pipe bomb was left on a ledge underneath the rail line on Amiens Street Bridge, adjacent to Connolly Station, in the north inner city.
It sparked a major operation yesterday morning, involving the evacuation of Amiens Street and its buildings as well as Connolly Station.
The army’s explosive ordnance disposal team was alerted. Experts conducted an examination and the device was made safe.
It was handed over to the gardaí and the device is now being examined by the Garda Technical Bureau.
Republican group Éirígí is planning to set up “camp” in the Garden of Remembrance on Sunday and intend to stay there until the Queen’s visit on Tuesday.
Garda sources said they will not be allowed to camp there and will either be prevented for accessing it on Sunday or removed soon afterwards.
Meanwhile, gardaí released details yesterday of travel and parking restrictions, as well as security searches on pedestrians and vehicles, in Dublin city centre, Phoenix Park and the main approach roads (N4, N7 and M50) starting on Saturday.
There will also be restrictions in Co Kildare for the Queen’s visits on Thursday to the National Stud, the adjacent Japanese Gardens, and Gilltown Stud.