SELECT road_numbers FROM table_name_33 WHERE build_year = "1943" AND railroad__quantity_ = "clinchfield railroad (12 new, 6 secondhand)"
Berapa angka jalan ketika tahun pembangunan tahun 1943, kereta api (kuantitas) adalah Clinchfield Railroad (12 baru, 6 bekas)?
CREATE TABLE table_name_33 (road_numbers VARCHAR, build_year VARCHAR, railroad__quantity_ VARCHAR)