Osaka was the second largest city in Japan, with a population of 3,252,340 in 1940. Traditionally, it was the most important industrial concentration in the Far East. Osaka was one of the principal centers of heavy industry, noted for its shipbuilding, iron, steel, rolling stock works, as well as non-ferrous metals enterprises (notably copper and aluminum). In addition, it was outstanding for its production of aircraft propellers and governors, munitions and ordnance, textiles, special steels, wires, electrical equipment, chemicals, instruments, and machines and machine tools, particularly anti-friction bearings. It had also become a transportation center, and ranked third as a port. Much work had been done to develop its naturally shallow harbor. Lastly, it was the center of an extensive