Officers found the four bombs stored in a derelict house not far from the M1 motorway.
It is suspected that the location on the outskirts of Dundalk, Co Louth, was specifically chosen by the gangsters because it allowed for the easy distribution of the devices.
Several local residents were evacuated from their homes yesterday as the army bomb disposal unit moved in.
"The Defence Forces deployed to Haggerdstown, Dundalk following a request from the gardai; the area had been cordoned off by the gardai and local residents were evacuated to a safe location," said a spokesperson. "The viable devices were made safe in situ without the need for a controlled explosion and will be removed to a secure military location for further examination."
Once those tests are completed army officials will hand over the devices to gardai to assist with their investigations.
The scene was declared safe at 6.15pm.
Security sources are alarmed at the ever growing prevalence of pipe bombs which are being traded by gangsters for as little as €100.
Just last week a Herald investigation reported how the Army's EOD unit was called out to deal with a bomb alert in the capital on average once a week last year.
Yesterday's haul is being linked to a gang in north county Dublin. It is believed that the group is manufacturing the devices for sale.
The target market is other criminals and security sources say that the location just a few minutes drive from the M1 motorway allowed for easy access for customers.
Figures obtained by the Herald show that 53 of the 96 viable improvised explosive devices (IEDs) dealt with last year were discovered in the Dublin region.
Hotspots include the Crumlin, Tallaght, Finglas and Coolock areas -- areas that have been the scene of a number of disputes between gangland criminals and separate feuds between Traveller families.