sentences:  Linker the Ulster Railway (UR) from Belfast to Portadown and Dublin and Drogheda Railway (D&D) from Drogheda to Dublin it completed the missing link in the Dublin to Belfast main line.On 6 January 1852 became a junction, when the northern section of the D&BJct was opened between Portadown and about beyond .Bridging of valley near Bessbrook by construction of Craigmore Viaduct delayed the running of through trains to just north of until 1852.