Experimental Projects

During their years at Alcoa of Australia, Bill France and Malcolm Torkington were required to perform volume calculations on the raw material stockpiles and the residue containment ponds. In order to complete the calculations, methods of data capture would be required that was not of the ordinary. Reflectorless theodolites were not invented and various methods tried utilizing existing equipment and methods. For the existing raw material stockpiles, cross section calculations were utilised as the mechanical stackers formed a long uniform figure and this was easily measured. The length was divided into regular intervals of fifty metres over a total length of 1500 metres and the height calculated using a clinometer. This method was quick and easy giving results to the necessary accuracy needed. The residue ponds were a different matter.

During the refining process, waste product is stored in ponds, large dams in excess of 1500 by 1100 metres in size. This residue is a slurry of water and chemicals and at the time this slurry was pumped into the large holding ponds. The mud or heavy material sinks to the lowest point and the water liquid is reclaimed back into the process. Capturing data for volume calculations was the challenge. A number of ideas were tossed around starting with a small timber and fibreglass barge that a commercial paper echo sounder could be placed into and by pulling the barge across the lake (all 1100 metres) utilizing large PENN fishing reels, a continuous paper chart of the bottom surface was printed. The idea was good but execution was another matter.

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Conventional levelling techniques were started for the so called hard mud surface. The distinction between hard and not so hard was soon established with the result being many trips to the showers and new uniforms requisitioned from the stores. The water line was needed and aerial photographs were examined however to fly the route every month was an expensive option so an old method was adopted. A Plane table and alidade was sourced trialled and eventually used as a quick and accurate method of drawing the water mud line. The lakes or ponds had grid markers placed upon each bank creating a 50 metre grid therefore utilizing these markers for the data collection was an obvious choice. The volume of liquid was calculated using the water line and depths achieved by the echo sounder method. To get the soundings a small dingy was purchased by an expert.

Little was left after it was in the caustic solution for a weekend so a new stainless steel boat was ordered. Safety of the operators (Bill and Malcolm) was paramount so it was tested for stability and many safety procedures put in place. This was to main method for a couple of years, then Bill was accepted into university and another idea was investigated. A remote control hovercraft was the idea and during his studies Bill designed and constructed a steel and timber hovercraft using two Honda stationary engines and air conditioning fans. Trials were successfully undertaken and Alcoa made an offer to part fund a fully working version. The engineering department of the University started a manufacturing facility to give students projects that were relevant to industry and after contacting them, they agreed to construct a lightweight hovercraft. After this collaboration a hovercraft was developed being a fully radio controlled platform to gather data.

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