Construction World March 2016

COVER STORY

for new Zambian grain operation MEGA DAMS JSE listed multidisciplinary construction group, Stefanutti

the site inspection, no rock was evident in any of the test pits. However, once we started the excavations, boulders larger than a standard car were unearthed within five metres of the test pits. This, as well as finding sedimentary and metamorphic rock types in the same material matrix, is extremely unusual for this area,” Pells explains. The task of moving these large volumes of rock is being led by a range of Cat earthmoving machines that are undertaking the grading, dozing, mass excavation, materials handling and compaction on the two sites. Robust machines for the task In October 2015, Stefanutti Stocks’ 22,4 tonne operating weight Cat 320D2 L hydraulic excavators were joined by a latest generation Cat 329D2 L fleet to meet the intensifying earthworks demands. Cat D5 dozers, given their compact design, were deployed in the trench bases, with Cat CS533E single drum soil compactors in smooth drum and padfoot configuration used for overall layer works preparation. The Cat 329D2 L is supplied and supported by Southern African Cat dealer, Barloworld Equipment, and is powered by a Tier II, Stage II Cat C7.1 engine generating a net power of 151 kW (compared to 112,5 kW on the Cat 320D2 L). It has a maximum operating weight of 30 115 kg. This makes the machine well suited to demanding applications that include quarrying, industrial materials handling and construction. Compared to its Cat 329D L predecessor, the new machine offers up to an 11 percent reduction in fuel consumption when set in economy mode without a noticeable loss in power delivery. “This is a robust machine that has stood up well to the demands on this project, especially given the rock volumes we have had to move,” says Pells. The intensity of the project is demonstrated by the fact that Stefanutti Stocks has had more than 40 tipper trucks on site. It has also employed articulated trucks for overburden haulage, as well as to trans- Elsewhere in Zambia, Stefanutti Stocks is working in parallel on key contracts that include the Bottom Road, which commenced in October 2015. This 107 km section traverses the north bank of Lake Kariba. The road, originally established in 1957 as part of the Kariba Dam construc- tion works, runs from Sinazongwe to Chababona and forms part of the Link Zambia 8000 national infrastructure upgrade initiative. Currently, the road comprises some 50 km of passable gravel, with the balance largely restricted to all-wheel drive traffic. The entire road is now being upgraded to an asphalt section. Other recent road contracts include the Lusaka International Airport to Arcades dual carriageway rehabilitation. Alongside road and earthworks activities, Stefanutti Stocks’ Building Division is forging ahead on a number of Zambian develop- ments. These include a new Central African Aftermarket facility in Kitwe for an engineering group, completed in late 2015. The Actis Logistic Park in Lusaka, which included infrastructure, roads and services in its contract scope was completed in the first quarter of 2016. A new hotel project is pending in Kitwe. A further cross-border operation sees Stefanutti Stocks Roads & Earthworks deployed at the Liqhobong Diamond Mine in Lesotho where it is the main contractor for all the earthworks phases. The mine’s majority shareholder, Firestone Diamonds, expects initial production at Liqhobong to commence during the fourth quarter of 2016. Back in South Africa, Stefanutti Stocks Roads & Earthworks under- takes projects in all provinces, including a number of recently awarded medium-sized road contracts currently underway in the Eastern Cape and KwaZulu-Natal. port and deposit the rock used to form the dam toes. Other Stefanutti Stocks contracts

Stocks, is at an advanced stage of completion on two clay core earth- fill embankment dams in Mumbwa, Zambia. The fast track projects see Cat machines forming a core component of the construction mix.

Operating from its home base in South Africa, Stefanutti Stocks is progressively expanding its African footprint. The group’s focus continues to evolve, with new oppor- tunities unfolding in East Africa and West Africa. Closer to home, the company operates throughout Southern Africa, with established operations in Botswana,

Namibia, Mozambique, Swaziland, Tanzania and Zambia. Stefanutti Stocks has been active in Zambia for the past 16 years and operates as a fully localised company. Stefanutti Stocks Construc- tion Zambia Limited offers its Zambian clients a turnkey focus on roads and earthworks, civil engineering and building and is currently busy with a number of projects in this developing country, which ranks as one of the world’s major copper producers. Abba and Katonga dams One project now at an advanced stage of completion entails the construction of two clay core earth-fill embankment dams, named Abba and Katonga, respectively. The project is being undertaken for German agricultural enterprise, Amatheon-Agri Zambia Ltd (part of the Amatheon Foundation), which is setting up an approximately 400 hectare grain farming operation (for wheat and maize) in Mumbwa, situated in Zambia’s Central Province. This will be fed via pivot irriga- tion, with the dams coming into play especially during the drier winter periods. These dams are substantial structures, with client funding sourced from Japanese and European entities. “In terms of the two dams, Abba will have a crest length of 550 metres, a wall height of 22 metres, an approximate capacity of 10,2 million cubic metres, and a surface area of 115 hectares when full,” explains Jonathan Pells, contracts director: Africa at Stefanutti Stocks Roads & Earthworks. The second dam, Katonga, will have a crest length of 1,1 kilometres, a wall height of 21 metres, a capacity of around 7,2 million cubic metres and a surface area of some 97 hectares. Both dams have core cut-off trenches to a depth of 10 metres, tapering to a final width of four metres at the base. As is standard for clay-core structures, these trenches were filled with impervious materials to protect the integrity of the dam walls and to prevent seepage. Between the two dams, the project scope has included the removal of 300 000 cubic metres of material and the placement of 800 000 cubic metres of fill material. It has also seenthe installation of 18 000 cubic metres of gabions, which serve as erosion protection on the dam spillway overflow sections. Rocky challenges At the onset, an unexpected challenge was the presence of major rock obstructions in the core trenches, which needed to be cleared. “During

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CONSTRUCTION WORLD MARCH 2016