Throughout history there have been inventions and discoveries that have changed the course of thinking, in particular the thinking of pioneers. Imagine the difference it made when engineers got the use of the rope, the wheel, writing materials, bronze, iron, nails, screws, drills, steam, electricity, petrol and nuclear power. All these advances and thousands more happened to some engineers, somewhere, in mid-career. Consider for a moment an electronics engineer born around 1930, who could still be in practice today. That engineer has had to adjust, in mid-career, to television, transistors, radar, the laser, computers, the harnessing of infrared, glass fibre, satellites, robotics and the evolution of whole new disciplines such as mechatronics, software engineering and information technology.
Bob Stanway reviews the legislative framework for transport policies and how this is likely to affect institutional structures Position papers on institutional restructuring in South Africa were delivered by Jack van der Merwe (Deputy Director- General of the Gauteng Department of Public Transport, Roads and Public Works) and Bob Stanway (Chairperson of Stanway Edwards Ngomane Associates), with the former taking a wider perspective by looking at public sector restructuring, change management, strategic management and the departmental staffing and functions within Gautrans. The latter paper concentrated more on the Green Paper on National Transport Policy, the associated legislative framework and the issue of transport authorities per se.
Francois Botes reviews the presentations relating to infrastructure funding and the resolution adopted at the conference In an environment of tight budgets and growing investment needs, the question of how transport infrastructure will be funded in the future has never been more important. The objective of the presentations in the session of the conference on transport infrastructure funding was to provide a background for assessing and debating the issue of the funding of transport infrastructure and maintenance.
The shape and pattern of urbanised land in South African metropolitan areas show common characteristics such as low-density sprawl, fragmentation of development and the separation of land uses, urban elements, races as well as income groups. The combination of a monocentric economic activity structure, where the majority of jobs and services are concentrated, with a dispersed settlement of high-density low-income areas at the urban fringe has many adverse effects on poor households. The adverse effects include the generation of enormous amounts of movement, high transport costs and unnecessary time spent on transport. Long trips reduce opportunities for low-cost modes of transport, such as walking and cycling. It also results in a unidirectional flow of traffic during peak hours, which contributes to congestion and unproductive use of road space. The low-density sprawl in higher income areas prohibits the provision of viable transport services.
An integrated water management strategy was applied to achieve both practical engineering and environmental objectives with regard to water control at the new Pullens Hope opencast coal mine Opencast collieries on the Eastern Transvaal Highveld are often situated in valleys where the depth of overburden to coal is small. Low stripping ratios result in economic mining, but mining in or through a valley necessitates dealing with the stream in that valley and two problems present themselves: Firstly, there is a distinct risk of flooding to the mine. Secondly, water entering either the opencast workings or the backfilled voids of the mine becomes saline and needs to be contained and dealt with in an environmentally acceptable manner. If this water is allowed to return directly to the natural streams, environmental damage could occur.
The paper descriptionbes a particular method which has been developed by the writer of constructing precast prestressed circular tanks. Precast panels, the full height of the wall, are erected on a ring foundation with gaps approximately 1 foot wide between them, these gaps being filled with in-situ vacuum processed concrete. A horizontal prestress is applied by stressed high tensile wire loops in contact with the outer face of the wall, the wire being covered with a protective rendering. After a general descriptionption of the method, the writer discusses some design considerations and finally descriptionbes the two 7 million gallon raw water reservoirs constructed for the South African Coal, Oil & Gas Corporation Limited at Sasolburg, Orange Free State.