Claim: In the Table of locomotives the class are categorized as F6 and F6-a and it was built from January 1930 to November 1931.
Evidence: F6 January 1930 June 1954 F6 January 1930 December 1954 F6 January 1930 February 1954 F6 January 1930 February 1954 F6 January 1930 December 1953 F6 January 1930 December 1952 F6 January 1930 September 1952 F6 January 1930 October 1952 F6 January 1930 October 1952 F6 January 1930 July 1954 F6 January 1930 September 1954 F6 February 1930 November 1954 F6 February 1930 December 1954 F6 March 1930 December 1954 F6-a October 1931 December 1954 F6-a October 1931 December 1954 F6-a October 1931 December 1954 F6-a October 1931 December 1954 F6-a November 1931 December 1954 F6-a November 1931 August 1952 F6-a November 1931 June 1954 F6-a November 1931 October 1952