Erin was one of two engines built by Hunslet in 1894 for the reopening of the Waterford and Wexford Railway and was bought by the Fishguard and Rosslare Railway and Harbours Company. The FRRHCo was jointly bought between the Great Southern and Western Railway(of Ireland) and the Great Western Railway(of Britain) in 1898 and Erin was absorbed by the GSWR. Erin continued to operate passenger services between Wexford and Rosslare Harbour until releived by the arrival of GSWR Class 47 0-4-4Ts. Erin was allocated a number 300 but this was for accounting purposes only as the GSWR beleived that engines should not bear both a name and a number. Erin later worked on Waterford Quays, Tralee and occasionally worked Fenit Pier throughout the GSWR and GSR before being withdrawn in 1930.