What are the works numbers where the year is 1929 and the driver diameter is 60"/1520mm? 
CREATE TABLE "class_16_da_4_6_2_builders_works_numbers" (
  "sar_no" real,
  "builder" text,
  "year" real,
  "works_no" real,
  "firebox" text,
  "driver_diameter" text
);
SELECT "works_no" FROM "class_16_da_4_6_2_builders_works_numbers" WHERE "year"=1929 AND "driver_diameter"='60\"/1520mm';