Another aspect of quality control of production items requiring scientific support was the radiological examination of castings and welds. Techniques in X-ray and gamma ray radiography had been developed at the Munitions Supply Laboratories and were applied to the examination of light alloy castings in the aircraft industry, to the examination of aircraft engine forgings, and to heavy castings and welded items. Personnel had to be trained in the new processes and centres of testing set-up in appropriate factories. From a core staff of one hundred and fifty at the beginning of the War the dispersed radiographic effort grew to eleven hundred in four years. In fact, from the Maribyrnong Laboratories flowed most of the scientific support for the systematic examination of defence material, embracing explosives, textiles, fuels, lubricants and paints

Being cut off from external sources of materials supply and without access to the accustomed sources of technological support, Australians had to rely on their own resources. The response was impressive and the nation's talent for improvisation was coupled with an ability to mobilise and co-ordinate its limited supply of technical and scientific manpower.

An immediate consequence to Australia of the reduction of British support in 1940 is exemplified in the production of gas-masks for the Services. The fear of gas warfare had remained since the First World War and the protection of both military and civilians had to be assured. Respirators were designed to give protection against mustard gas; the technology incorporated in the filters was of British origin but, as supplies of Chinese feather-down impregnated with lamp black became unavailable, substitute merino wool and asbestos mixtures had to be investigated. MSL has been charged many years before by the Gas Warfare Board to acquire knowledge in this field; although machines to produce suitable fillings had been ordered from the United Kingdom, the inevitable delay in delivery could not be accepted. Down fillings of Australian origin had to be developed, and the standard charcoal absorbers had to be modified to give protection against arsine gas. A process of impregnating with silver nitrate was developed.

Over half a million service respirators were produced in six months in 1940; all production remained in the laboratories because of material problems. A substitute for the glass composite eyepiece had to be found, because there was no machinery in the country for its manufacture. Cellulose nitrate was tried, but eventually toughened glass was adopted. The tropical environment of the war led to new formulations of the rubberised material and the demand for new designs of respirators. Later, the threat of gas warfare receded and the research effort was directed elsewhere.

Australian Academy of Technological Sciences and Engineering