The GWR 2721 Class was a class of 0-6-0 saddle tank steam locomotives. They were designed by William Dean and built at the Swindon Works of the Great Western Railway between 1897 and 1901.They were not a new design being a straightforward development of the 120-strong 1854 Class dating back to 1890. This lineage had begun with George Armstrong's 645 Class in 1872 and continued via the 1813 Class (in 1882) the 1854 Class and finally ended in 1948 with the GWR 9400 Class. 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?
A:
Mean Of Transportation