WINDHOEK – Many Namibians, particularly motorists, have witnessed the gradual arrival of massive tipper or dumb bodies along the country’s national roads as they are being transported to the N$20 billion Husab Mine.
These dump bodies, which are the bins on the back of gigantic haul trucks to be used on the mining site, are so huge that most times oncoming traffic has to be diverted to the side of the road to enable the massive loads to pass. Swakop Uranium, which is constructing the Husab Mine, is a Namibian company owned by China General Nuclear Power Holdings Co, China Africa Development Fund and Namibian State-owned mining company, Epangelo Mining. Once in operation the Husab Mine will use a fleet of 39 of these haul trucks. To date, eight dump bodies have been delivered to the Husab Project site. The transportation of the dump bodies poses a huge logistical challenge for Swakop Uranium as the dump bodies, which are manufactured in Johannesburg, are 14.6 m long by 10.7 m wide by 5.4 m high. Due to their size, convoys are limited to three dump bodies per trip. The route from Johannesburg takes the dump bodies through several South African towns, including Wolmaransstad, Warrenton and Upington, before entering Namibia via the Nakop border post. From there they normally travel via Karasburg, Rehoboth, Windhoek, Karibib and Usakos to the Husab site in the Erongo Region.
Prior to loading the abnormal vehicles that transport the dump bodies, an application for an abnormal load vehicle exemption permit is submitted by the transporter to the Roads Authority. The application includes the proposed route, loading plan and vehicle details. The permit is then issued and coordination with the Namibian Police and the municipal traffic authorities commences. Loads such as the dump bodies are strictly controlled and police escorts must guide and direct the abnormal vehicle throughout its journey. At no time can the vehicle deviate from the route unless directed by Nampol and municipal traffic. Says Komatsu’s Gerhard Klopper:
“Every step of each journey has to be carefully measured and investigated before the 50-tonne freight can be granted permission to travel. Even then, strict conditions are applied and the vehicles need to be accompanied by at least two escorts from Transcor, as well as two road traffic authorities at all times. Everything needs to be planned – from the distance that could be covered during daylight hours, to powerline heights and bridge weight carrying capacities.” Swakop Uranium’s Grant Marais, Director for Communication and Stakeholder Involvement, explained that before the first trip commenced, bridges were measured for width and weight and culverts were measured to ensure that the lower part of the dump body did not damage the barrier built on the road either side of the culvert.
“In certain areas, the dump bodies have to be ‘jacked’ up so that they would clear the culvert barrier and bends checked to ensure that the lowbeds transporting the bodies could negotiate them without causing damage to the road or infrastructure. At the borders, fences and stop signs often have to be removed to make space for the trucks and replaced once the convoy had passed,” explained Marais. He added that escort vehicles are used to ensure that all road users are warned of the approaching convoy, so they could pull off the road safely and allow the convoy to travel to their next stopping point. Daily tracking reports are sent to the various stakeholders to inform them of the progress and positioning of the convoy.
“The last leg of the journey furthermore requires strict adherence to the Namib Naukluft National Park regulations and the convoy teams had to attend a safety induction and awareness briefing on the park. Parts of the Welwitschia Road had to be widened slightly for safe clearance and to avoid vegetation. The dump bodies are finally loaded off at the Husab Project site by way of a tandem lift, using an 80 tonne and a 90 tonne crane,” said Marais.
The convoys travel at an average speed of between 50 km and 70 km per hour. The first two dump bodies started the 2 250 km journey from Johannesburg to the mine on June 4, 2013, and arrived at the Husab site on June 28. Alternative routes are sometimes used because of road construction and directives from traffic authorities and it takes on average 2 to 3 weeks as the transporters and traffic authorities are getting more familiar with the routes. The dump bodies are manufactured by a company called Efficient Engineering, based in Johannesburg. Marais also remarked that the only other option to transport the massive loads was by road to Richards Bay (with similar logistical challenges) and then ship them from there to Walvis Bay. This option, however, was described as a much more expensive one. One of the first people to give fruition to the dream of having the very real and very big yellow machines to start the excavation of Husab’s two mining pits, is Rainer Horsthemke, Komatsu’s Operations Manager for the Husab Project. “We have received the complete components of the first two Komatsu 960E-2KT haul trucks at the premises of Wesbank Transport in Walvis Bay,” said Horsthemke.
“The contract to assemble the trucks was awarded to a local company, Rotary Mining. The assembly started in August 2013 and we have a tight deadline to meet,” he added. This deadline will see Komatsu deliver 11 haul trucks to the mining teams by the end of January 2014.
The Komatsu 960E-2KT haul truck is rated to carry 327 tonnes. Its diesel motor delivers 2 600kW of power (3 500 horsepower) and is coupled to an alternator that sends power to two Siemens AC (alternating current) induction traction motors mounted on each side of the back axle. The ‘T’ in the model name refers to ‘trolley-assist’, whereby the truck can couple onto overhead power lines using a pantograph mounted above the cab.
“We receive each Komatsu haul truck in sections comprising the chassis with the engine, radiator and rear axle box fitted. This section alone weighs 64 tonnes,” Rainer explained.
By Edgar Brandt