In 1933 the Great Western Railway introduced the first of what was to become a very successful series of railcars which survived in regular use into the 1960s when they were replaced with the new British Rail first generation type diesel multiple units. 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?
Mean Of Transportation