POWERHOUSE COLLECTION

Computer hardware cabinets, part of computer system used by Transgrid NSW

Object No. 2008/58/1

The computer hardware cabinets contain the minimum operable configuration of a computer system that controlled the distribution of high voltage electricity through NSW, Australia between 1985 and 2003. Transgrid, the organisation that donated these cabinets, oversees and coordinates high-voltage electricity transmission in New South Wales. They are one of the companies that were formed to take over the duties of the former State Electricity Commission. The TOSBAC Series 7/70E System, of which these cabinets form a part, is a Supervisory Control and Data Acquisition (SCADA) system designed and marketed by Toshiba. It runs TREX 2 (Toshiba Real-time EXecution) which is a special operating system for SCADA. While the TOSBAC and TREX comprise a computer system designed for general control application, this system was especially commissioned to run the State electricity grid in NSW. It was purchased in 1982 and was running by 1985. DAC, (Data Acquisition and Control) as it is known by the Transgrid engineers who operate the system, is the third computer system to have been used to control the grid. The first was an analogue computer from Leeds and Northrop called 'George' which was installed in the mid 1960s, and the second system was a PDP/11 called 'Little George' which ran from 1978 to 1985/6 when DAC was brought on line. The TOSBAC system illustrates the use of computers to implement sophisticated control of a major public utility, and the importance of computer systems to our technological infrastructure. It was still in use up until 2003 and had been controlling NSW's high-tension transmission for the better part of twenty years. Prior to the grid being set up, power stations had to be built at the site of the power requirement. For example the Powerhouse Museum currently resides in the former power station built to supply electricity to Sydney's tram system. The understanding of power transmission has had implications for computing history. American scientist and engineer Vannevar Bush built his famous differential analysers in order to perform the calculations necessary to understand the behaviour of transient signals in electricity transmission lines. Moreover, this computer system represents an essential aspect of industrial and technological practice: control. From the governors used with industrial steam engines in the 1800s through to the operating system on personal computers, all technology requires a control system. Electricity is one of the most valuable and volatile elements of modern life. A highly sophisticated and reliable method of control is required to enable the safe delivery of electricity. The TOSBAC system is a significant example of a control system designed to manage an often unpredictable but essential commodity. Damian McDonald October 2007