Early technology (continued)

In competition with electricity, the use of gaslight was prolonged by the Welsbach Incandescent Burner developed in Germany in 1887, which produced a brilliant light by heating a mantle. Far more economical than standard gas lamps and further improved with automatic clockwork controls, incandescent gaslight was retained in some municipalities until the 1920s.

In the cities, where the demand for gas continually increased, mechanisation was introduced progressively from the later years of the 19th century. At the Works, automatic stoking machinery was used for gas production and elevators and light rail systems transported the coal and coke. For gas distribution, boosting engines were employed where high pressure mains were laid and larger and larger holders were built to supply areas remote from the manufacturing plants.

In general the smaller gasworks in Australia continued to use horizontal clay retorts but in the larger gas works the horizontal retort was supplanted by the inclined retort in the 1890s and later by the intermittent vertical retort system. The greatest change in gasmaking technology, however, was the introduction of the continuous vertical retort developed in Britain in 1911. This was immediately adopted by the larger Australian gas companies. Constructed of fireclay moulded sections, the seven metre retorts tapered from top to bottom. Their vertical installation made use of gravity to charge them from the coal hoppers situated above and aided the efficient use of heat. Gas was taken off at the top of the retort and at the base an extractor continuously turned out coke, which was removed at two-hour intervals. There was a considerable saving of labour and a great improvement in retort house working conditions.

26 Australian Gas Light company's Mortlake (Sydney) carbonising plant in the 1950s. (Australian Gas Light Company Ltd. photo)

Although electricity became the preferred source of illumination as the 20th century progressed, gas continued to keep its place as a viable form of energy. Gas was retained in some industrial processes and competed successfully in the domestic market due to the continuing popularity of gas cooking and promotion of gas hot water and gas refrigeration. Consequently the demand for gas production remained high and most Works met their requirements with a variety of production methods.

During the 1920s and 1930s attempts were made to construct successful complete gasification plants. This technique originated in Britain and Europe, but its implementation in this country was brought about by two Australian gas engineers who built plants of their own design, C. F. Broadhead of the Metropolitan Gas Company in Melbourne and Herbert Wood, whose plant was used by the Manly and Bathurst Gas Companies. The complete gasification plant attempted to maximise the yield of gas by combining the action of vertical retorts with that of water gas plants which extracted the last vestiges of gas from coke. These complete gasification plants provided a valuable means of meeting peak winter demand during the late 1930s and early 1940s.

Australian Academy of Technological Sciences and Engineering