The Northern Counties Committee (NCC) Class S2 was a solitary two-cylinder compound 2-4-4T steam locomotive that was introduced for service on the 3ft (914mm) narrow gauge railways of County Antrim in north-east Ireland. It was heavily rebuilt from a BNCR Class S locomotive by the addition of a standard gauge boiler. Given a list of categories: company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, what category does the paragraph belong to?
Answer:
Mean Of Transportation