 The type regularly replaced Dugald Drummond's ageing LSWR T9 class 4-4-0s on portions of the Atlantic Coast Express over the steeply graded mainlines west of Exeter.The N class was also successful on the Central section, where they worked alongside L. B. Billinton's LB&SCR K class 2-6-0s.However the large cylinder and cab sizes of the N class prevented use of the type on the Eastern section's Tonbridge–Hastings line.