MODELS ASSISTED OVERCOMING MAIN HYDRO PROBLEMS

Bay of Plenty Beacon, Volume 15, Issue 6, 6 March 1950, Page 8

MODELS ASSISTED OVERCOMING MAIN HYDRO PROBLEMS

Models of the Maraetai and Roxburgh dams are included in an exhibition at the Dominion Physical Laboratory. They have been consti'ucted to help solve the engineering problems which have to • be overcome. On the Maraetai penstock model tests are being made to determine if one penstock has sufficient capacity to act as a secondary diversion tunnel while the main diversion tunnel is being plugged and converted into a spillway tunnel. Flow Conditions Later tests —are conducted under the control of Ministry of Works engineers—will be carried out to investigate flow conditions in the river bed below the discharging penstock. A two dimensional preliminary model of the Roxburgh spillway has been made to indicate the flow conditions through a sluice and the effects of omitting a plug from the downstream end of a sluice when floodwaters are discharging over a spillway. Another model of the Roxburgh dam and river is nearing completion for tests to determine the hydraulic conditions during the diversion of the Clutha River and the various stages of construction. It will also demonstrate the efficiency of the final spillway system. \ Though five months will have passed before the Roxburgh model is finally completed, it is quicker to build it than to calculate mathmetically how the dam should be built to withstand all the stresses to which it will be subjected. Made with transparent sides, the models clearly demonstrate how the final structures will react to the water they will have to handle in helping generate power. They are modified as necessary until engineers are thoroughly satisfied with them. Only Small Part The models are only a small part of the large range covered by the exhibition. Sections deal with electronics, electron microscopes, metallurgy, standards, geophysics, radar and radio, nucleus physics, instrumentation, machine-room display, grind-ing-room work, glass working, heat treatment and building and civil engineering research.