user: Question: When was the motor gear of the LMS 1946 no. 1901 model fitted?
Columns: ['LMS 1932/3 No.', 'LMS 1946 No.', 'BR No.', 'Date built', 'Date motor gear fitted', 'Withdrawn']
Types: ['real', 'real', 'real', 'text', 'text', 'text']
Sample row: [6400.0, 1900.0, 41900.0, '1932–12', '1950–9', '1962–3']
SQL:

assistant: SELECT "Date motor gear fitted" FROM "Table" WHERE "LMS 1946 No." = 1901.0;