going, the design was changed to accommodate these ‘post-Panamax’ behemoths. The revised design specification will give Durban a distinct competitive edge over other ports and enable it to accommodate the larger container vessels— which deliver lower freight costs to shippers and industrial end-users alike but so far do not call at African ports. The project was an opportunity to clear out a number of hazards from the harbour, including four concrete caissons deliberately positioned to prevent U-boats from slipping in during World War II. These had to be removed ahead of the dredging operation, and the original plan was to lift them intact and dump them out to sea, says project manager Dave Ward. “Achieving this was quite challenging because the structural integrity of these caissons had deteriorated with the result that we could only do that in sections. We did manage to float one caisson out, but the rest we had to cut up into much smaller pieces using advanced technologies such as underwater diamond saws.” Another surprise that turned up well into the contract was the discovery of an unknown wreck in the channel for which historical records were unavailable. “The approach to the identification of the wreck and rendering it harmless to shipping while meeting the objectives of the project was in itself a significant achievement,” says Ward, who emphasises that the speed and efficiency with which this project was brought to completion in February 2010, a month ahead of schedule, can be attributed mainly to good communication between the Port authorities, the shipping lines and the contractors and subcontractors. “We
were able to execute some of the dredging work ahead of time, even in the navigable channels, without disruption to shipping and the working Port. It was business as usual.” With around 8,000 ships utilising the harbour every year that was quite an achievement, he adds. “Throughout the project we were able to keep the traffic going in the Port by doing all the work on the north side first, then diverting all the traffic into the channel on the north while we then turned our attention to the south channel. That proved to be very successful.” In February 2003, coastal engineering consultants Prestedge Retief Dresner Wijnberg were appointed jointly with the CSIR Stellenbosch to undertake the preliminary design work. The main contract for the works was awarded in May 2007 to a consortium comprising Dredging International of Belgium and Group Five of South Africa, while project management was carried out by Transnet Capital Projects and its joint venture EPCM (engineering, procurement and construction management) contractor HMG (Hatch, Mott MacDonald, Goba). The type of contract used was the New Engineering Contract (NEC), and Ward believes this was a key factor in managing risk and controlling the project, thereby overcoming potential problems. “The NEC form of contract is based on mutual trust and cooperation between contractor and client. This assisted all stakeholders to focus on project objectives and find solutions.” Safety is always a good indicator of how well a project is being approached, and the project achieved one million hours without an LTA (lost time accident). “Health and safety were constantly enforced,” Ward says. However, the outstanding safety record also depended on the quality of collaboration between the contractors and project management teams, and their experience. “We were pleased that even the newer but more innovative subcontractors found in the project an excellent opportunity to stretch their capability in partnership with a global player like Dredging International. This assists in demonstrating the expertise available in South Africa and is good for the construction industry. An example of this is the Durban-based commercial diving and marine construction company Subtech, for whom this was a significant contract where they were