Static and dynamic weigh- ing technology specialist Cardinal Weighbridge Company South Africa (CWCSA) has replaced the underperforming train weigh- ing system at JSE-listed sugar producer Illovo Sugar’s Noods-berg mill, in KwaZulu-Natal.

Illovo Sugar Noodsberg project engineer Craig Lipsett says the old rail weighing system was unreliable, resulting in inaccurate weighing of rail cars and trucks loaded with sugar.

This sugar is typically transported and distributed to African consumers and industrial markets, particularly in South Africa, for final distribution by road to their customer base.

“Owing to the unreliability of the system, many of the rail cars were underfilled to prevent excess train weight exceeding the legal rail freight limit set by State-owned freight logistics group Transnet Rail. This was a costly and uneconomical exercise, and showed poor use of the rail transportation system,” he explains.

Illovo Sugar’s brief for CWCSA was to manufacture a “reliable, accurate and cost effective” weighbridge that could be adapted to the sugar producer’s existing loading system and within the existing confines of its rail loading facility at the Noodsberg mill.

CWCSA’s assessment was aimed at fully understanding the client’s existing problems and the type of rail car required. It also needed to propose a solution that would fit and work within the confines of the existing load-out station.
Based on this assessment, CWCSA’s design team proposed a static weighing solution that would enable the system to use three individual weigh platforms with the ability to weigh cargo as one weighbridge, if required. The design had to consider two types of rail cars that could be filled using the existing twin outloading spouts.

The final system design was for the supply of three in-ground weigh platforms, measuring 6 m × 3 m and 8 m × 3 m. Each platform, controlled and monitored using the Gravity system controller, was fitted with four load cells per platform, giving an overall length of 22 m. The system controller enables the facility to switch between each platform and measure cargo units individually or with another unit.
Meanwhile, existing outlet spouts facilitate the filling of the trucks, which enables an operator to select a weighbridge after identifying the type of rail car to be filled. The system will automatically tare each rail car arrival on the weighbridge and provide a tare weight record.

Once the preset full set point is reached during filling, a signal to stop filling can be given to stop the feed supply. After a short delay to allow for any in-flight material and settling of material in the rail car, a final gross weight is recorded.

Consulting civil and structural engineering group Liebenberg, Jenkins & Partners project manager Leon van de Linde says the operator will then be able to print out the individual weight records or a total weight of the train on completion of the filling of all the rail cars.

Liebenberg, Jenkins & Partners has been commissioned to construct the concrete pit that the platforms will be lowered into.

“Another consideration that the design team had to overcome was the low headroom under the twin silos and how the 12 t platforms could be manoeuvred and installed safely into position above the preconstructed inground pit,” explains Van de Linde, adding that this is an indication that the construction phase has gone well. The concrete cast was completed, with no other modifications or alterations required.

The concrete platforms were designed and manufactured by CWCSA. Within the design of each weighbridge, CWCSA design engineers included built-in inspection points by means of access manholes and the facility of preset lifting points to facilitate ease of installation.