The Long-gone Industries of Concord (Pt.3)

Industries of Mortlake  – Cabarita

Australian Gas Light Company

Concord’s most significant industrial complex was also one of its earliest. The Australian Gas Light Company was established in Sydney in 1837, only twenty-five years after the world’s first gas company had been formed in Britain. In the 1830’s the city of Sydney was lit by ineffective oil lamps. By the 1880’s gas lighting had become established as the most effective method and suburban growth meant that gas consumption and demand were increasing at a rapid rate. To satisfy that demand, the Australian Gas Light Company purchased thirty-two hectares of land at Mortlake in 1884.

Gas was made by heating coal in ovens or retorts that excluded air. The nineteenth-century retorts, built of fire bricks in benches of up to nine retorts to one producer, were horizontal. Their charging and discharging was a hot, dirty and labour-intensive operation. To ensure a steady supply of gas at an even pressure capable of reticulation, gasholders were situated at the works and at points throughout the company’s supply area.

The development of a site as large as Mortlake represented a change in policy for the AGL Company which had previously attempted to satisfy the ever-increasing demand for gas by building relatively small works at different parts of the metropolitan area – the original works at Darling Harbour had been supplemented by smaller works at Balmain and Five Dock. The expansive site at Mortlake, selected ‘after much deliberation’, offered apparently unlimited room for growth and answered the needs of the company’s foreseeable distribution system which encompassed Sydney and its suburbs to the east and south and, later, to the west.

The site offered easy access to Sydney by both land and water. A jetty was built to allow direct delivery of coal by collier, while the land access provided a path for the company’s mains. For many years gas from Mortlake travelled nine kilometres to join older mains and improve the supply to Burwood, Ashfield, Strathfield and Canterbury. Although initially the Darling Harbour works continued to supply the city and inner suburbs, it was not long before Mortlake gas was extended to the city mains and travelled to St Peters, Marrickville, Rockdale and Randwick.

After the AGL Company purchased the Parramatta Gas Company in 1890, Mortlake was well suited to supply the districts of Parramatta, Granville and Prospect. The building of the Ryde railway bridge in 1896 allowed gas mains from Mortlake to cross the river and reach Ryde, Gladesville and Hunters Hill. Thus Mortlake quickly became central to the company’s operation and the works at Balmain, Five Dock and Parramatta were closed down. The site’s natural rocky outcrops were levelled for the building of two retort houses. With a length of eighty-five metres each, they were at the time the largest in Sydney. The accompanying holders, over thirty metres high, were also on a scale never seen before. Built close to Tennyson Road, these holders radically changed the appearance of the Municipality of Concord. So too did the increased river traffic as colliers steamed regularly up the Parramatta River to be unloaded by steam cranes at the jetty at Breakfast Point.

By 1890 the `village’ at Mortlake was the most densely populated area of the municipality. As well as the coal and coke handling, labouring and stoking work that were obviously necessary for the production of gas, the workshops at Mortlake, being almost self-sufficient, provided work for many tradesmen. In 1896 the Mortlake gasworks employed an assistant engineer and three clerks, sixty-three lamplighters, and 212 stokers, mechanics and yardmen – a total of 279 men. Local foundries also expanded to make castings which were then completed by AGL workmen.

Larger and more sophisticated than Sydney’s earlier gasworks, this first stage of Mortlake’s development was planned and executed before the electric light was seen as a serious challenge to gas lighting. In 1897 the streets of Concord were supplied with the newly developed Welsbach Incandescent Burners to celebrate the AGL Company’s diamond jubilee. Gas street lighting was still being installed until the end of World War I, by which time consumers were being offered a range of novel gas appliances such as radiators, bath heaters and irons. Demand for these gadgets gradually increased and continued the pressure on the Mortlake works.

During World War I the works at Darling Harbour were closed and the site resumed by the government. While electricity gradually extinguished the gas lamps of Sydney, two new retort houses rose at Mortlake. These contained the new vertical retorts, which significantly improved the efficiency of the coal carbonisation process. A third gasholder, much larger than the original two holders, took its place on Tennyson Road. Telpher tracks, supplied with electricity from the works’ own power station, were installed to move coal from the new wharf to the bunkers above the retorts. Accompanying plant and the increased workshop area provided an even wider variety of jobs for the treatment of marketable byproducts as well as in the gasmaking process itself.

The twin problems of fluctuating seasonal demand for gas and mountainous stockpiles of coke were solved by the increasing use of carbureted water gas plants. These, together with the space-saving qualities of vertical retorts, made it possible for the gasworks at Mortlake to meet the needs of all the company’s consumers until coal carbonising ceased in 1971. The increasing demand for gas was met by the building of a fifth retort house and three manually operated water gas plants before the 1930’s, and by the addition of a sixth retort house, a fourth water gas plant, a new tar distillery and another holder before the outbreak of World War II.

Problems with coal supply and government directives for the production of alternative fuels during the war years, combined with industrial troubles and rising coal costs in the immediate postwar period, brought diversification to the Mortlake works. In the 1950’s, as there was no longer a ready market for coke, the use of petroleum products in gas making increased.

By 1960, as sales of gas were rising, gas at Mortlake was being produced by all the methods that had been devised in more than a century of the industry’s history. Operating at Mortlake were four enormous houses of vertical retorts, seven water gas plants, four housed in the second retort house, two oil gas plants and one ballast gas plant.

The works transport scheme, too, was changing. The last locomotive was removed in 1949 and conveyor belts replaced the Telpher system. Electrically driven prime movers and mobile cranes superseded their steam driven predecessors while diesel powered back loaders and other earth moving equipment further reduced the labour of moving materials around the site.  While coal supplied the main feedstock of production, the workforce remained very large, peaking during the 1960s at 2000 men, a large proportion of whom were the tradesmen who kept the plant going.

By the end of the 1960’s, however, the use of coal as a universal fuel had finished. Its once-valued byproducts now had few markets and the smoke produced by its burning was no longer a source of civic pride but a problem for pollution controllers. The market for gas was supplied from catalytic reformers, which converted a feedstock of naphtha to towns gas. Coal carbonising ceased in 1971 and the four catalytic reformers then in use occupied only a fraction of the space that had been needed to produce coal gas. The smoke, dust, heat and most of the noise cleared from the municipality, the prime movers disappeared from the wharf and the colliers stopped their journeys from Newcastle. The huge concrete coal bunkers emptied and the stockpiles of coke and iron oxide heaps disappeared from around the dam. The retort houses were silenced and all were removed except for two whose shells were retained to protect the residents across the river from the hum and hiss of the catalytic reformers.

These reformers converted natural gas into towns gas for domestic consumption. They remained at Mortlake until Sydney consumers supplied from the works had their appliances converted for direct supply of natural gas. Then the holders, which are among Concord’s best-known landmarks,  disappeared.

In the 1960’s, 140 men were needed to operate the retorts in each shift but with the changeover to natural gas it only needed four to work on the reforming plants and two in the computer room to monitor the natural gas pipeline and control supplies to the Australian Gas Light Company’s still-growing district.

The works were demolished in the 1990s, and replaced by a large residential development – Breakfast Point Estate.