Government policies to develop war-related industries were successful in increasing the sophistication of Australia's industrial sector and self-sufficiency in most categories of weapons. In the decades leading up to the war successive Australian governments had provided subsidies, tariffs and other incentives encourage the development of military-related manufacturing sectors such as the production of aircraft, automobiles, electronics and chemicals. These secondary industries were integrated into a war economy during 1940 and 1941, and were able to meet most of the Army's needs by 1942. Government-led efforts to develop and manufacture advanced technology enjoyed some notable successes, including the development of lightweight radar sets, optical devices for artillery and equipment adapted for use in the tropics. Australian industry also developed new weapons which were mass-produced for the military, including the Owen submachine gun and a shortened version of the Ordnance QF 25 pounder. In addition, Australian scientists and pharmaceutical companies made important advances in the treatment of tropical diseases. Not all development projects were successful though: efforts to develop an Australian tank (the Sentinel) did not cease until after it had been rendered obsolete and unnecessary, and the development of Australian-designed advanced bomber and fighter aircraft—the CAC Woomera and CAC CA-15 respectively—were abandoned as the engines these aircraft required were not available and adequate US and British designs were produced under licence instead.