The area between Johannesburg and Pretoria has the fastest rate of economic development in southern Africa. The Gauteng Rapid Rail Link, running at speeds of up to 180 km/h, will be a new rail mass transit system that will serve the Johannesburg-Pretoria corridor, as well as a link between Sandton and the Johannesburg International Airport industrial development zone.

The new rail system will cover approximately 80 km with eight stations and a host of associated infrastructure.

The project, one of the 11 Blue IQ projects, will cost in the region of R7 bn, and will create 42 000 job opportunities during the construction phase, which is planned to start at the end of 2003.

After construction is complete, the project is expected to create and sustain 60 000 jobs a year in the vicinity of the stations and associated infrastructure.

With the project on a tight time line, it is essential for the consulting engineers involved with the preliminary design work, to make use of cutting-edge design technology. After extensive investigation, the MXRail civil engineering design software from Infrasoft was chosen. TechnoCAD, a local software development company specialising in civil engineering design software, and Infrasoft have partnered to produce a fully localised version of the software. The software natively supports the Southern African Lo survey system (WGS84 or Cape Datum), as well as UTM and other survey systems used throughout the world. In addition, Southern African railway design parameters have also been incorporated in the software.

"Localisation of global software for African conditions is extremely important," says Peter Webb, director of TechnoCAD. "With MXRail, we have taken a globally recognised cutting-edge technology and incorporated southern African design parameters. We now have an extremely powerful design tool, which is being used extremely effectively by the consulting civil engineers."

MxRail has been developed in conjunction with internationally renowned railway engineers and provides automated track design solution. Using comprehensive data import and analysis tools, MXRail can ensure that any existing surveyed rails are accurately defined at a very early stage. "Rails are modelled using MXRail's unique three-dimensional string modelling techniques", says Webb. "The same technology is used in our sister product MXRoad, already being used extensively for major highway development and grade separated interchanges in southern Africa. The three-dimensional string technology provides an intuitive solution to the problem - you just cannot use template-based solutions for a design problem such as this.

"Horizontal dynamic regression offers a new approach to track alignment that allows for efficient multiple analysis of potential track designs. Best-fit analysis of straights and curves can be carried out dynamically and in plan. Furthermore, it can be used to keep slews to desirable limits for realignment work, with all the relevant information constantly provided on screen, enabling designers to quickly locate track misalignments and survey errors."

Using dynamic three-dimensional alignment techniques, rail engineers can design horizontal and vertical profiles, which are the basis for the design of tracks, turnouts, crossings and layouts. Track and switch rails are modelled in 3D, giving complete definition of design. Cant (super elevation) is automatically calculated and applied. Turnouts are provided in a library, which now includes the commonly used ones in southern Africa.

MXRail automatically creates high quality drawings with routines for the production of plan and profile contract drawings. Complete with interactive graphical tools, the sheet and page layouts can be customised, then used again. MXRail long sections can be created to show cant and cant deficiency schematics. One of the key features of this design software, is that it is able to run inside AutoCAD, the CAD platform software from Autodesk. "We are very pleased to have the opportunity to be involved with a project such as this," says Webb. "It has given us the opportunity to mould global technology to solve local civil engineering design problems."

For further information: TechnoCAD 011 803 8834, sales@technocad.co.za