Located in Mpumalanga , the Kusile Power Station project consists of a power station precinct , power station buildings , administrative buildings ( control buildings and buildings for medical and security purposes ), roads , and a high-voltage yard . The associated infrastructure will include a coal stockyard ; coal and ash conveyors ; water-supply pipelines ; temporary electricity supply during construction ; water and wastewater treatment facilities ; ash disposal systems ; a railway line ; limestone offloading facilities ; access roads ( including haul roads ); dams for water storage ; and a railway siding and / or a railway line for the transportation of the limestone supply . In February 2011 , Esor Franki was awarded the P26 Terrace Underground Facilities contract at the Kusile Power Station in Ogies , Mpumalanga , which consisted of all the interface piping between the bulk supply systems and the terminations to the buildings on the power block , and was mobilised to site in March 2011 . The entire contract comprises the installation of drainage systems and high-pressure fire and water supply piping in a range of diameters from 150mm to 630mm for pressure lines , and up to 2 500mm for bulk stormwater lines . The total meterage to be installed in the contract period is in the order of 50km of networked pipe . The balance of the contract comprises the installation of two HDPElined holding recycle dams and 10km of in situ concrete networked cable and pipe tunnels . It is the Esor Construction part of the contract that this article covers .

Esor ’ s scope of work

Alex Keevy , contracts director at Esor Construction , explains the scope of work undertaken by the company . “ Most of our work is underground , and consists of piping and large-diameter concrete drainage works , up to 2 500mm . Also included in our scope of work is 11km of underground , cast in situ cabling trenches , which vary in size and depth , but on average are about 9m 2 , in which thousands of kilometres of electrical cabling is housed . Some of these trenches are up to 10m below GL ,” he adds . Esor handled the HDPE piping for potable water and also the piping for fire water .

Included in the above surface drainage works are open V-drains , which are built around the perimeter of the coal stockyard that feeds coal to the six units .

The volume of water coming out of the coal stockyards amounts to thousands of litres , as not only must the stockpile be dampened down daily to prevent spontaneous combustion of the coal , but rainfall must also be drained away to the stockyard dams . Keevy describes how the stockyard itself is lined with concrete and is tapered from the centre to the edges to facilitate efficient draining , which is further enhanced by an intricate drainage network below the concrete slab that feeds the water into the V-drains and ultimately into

14 - CEC February 2018

The Civil Engineering Contractor February 2018 | Page 16