Great Northern Railway Class P were two sets of 4-4-0 locomotives for the Great Northern Railway of Ireland (GNRI) introduced from 1892 by locomotive superintendent J.C. Park; four having 6 ft 7 in (2.01 m) driving wheels and eight having 5 ft 7 in (1.70 m) driving wheels. Park was succeeded by Charles Clifford who constructed 17 broadly similar locomotives from 1896 with 6 ft 7 in (2.01 m) driving wheels; these were designated Class PP.[2] The last PP class survived until 1963.[3]