Following Transnet National Ports Authority’s (TNPA’s) ongoing efforts to address shallow spots exacerbated by the size of megaships now calling at the Port of Durban, harbour master Captain Alex Miya has reinstated a number of berths back to their original permissible draughts.

“The vessels calling at our ports have gotten bigger and, therefore, require deeper draughts. But they also cause challenges for ports because of the manner in which they more aggressively displace material from the seabed, causing shallow spots.

“Shallower berths can cut into the vessel payloads of ship owners because it means they cannot sail into the port with their vessels fully laden and have to wait for high tide to sail or berth,” explained Durban port manager Moshe Motlohi.

The permissible draught referred to the vertical distance between the sea bottom and the lowest part of the ship’s underside, otherwise known as the under-keel clearance.

The Durban port allowed a 600 mm clearance to minimise the chance of the vessel running aground in that area.

Four of the eight container berths at the Durban container terminal (DCT) had recently been called back to their original permissible draught of 12.2 m, while Berth P at the Point Terminal, Berth MW9 at Maydon Wharf Terminal and bulk Berth BCA 4 in the Island View precinct had also been called back to their permissible draughts of 10.3 m, 9.3 m and 10 m respectively.

“We are also expecting engineering sounding results that are likely to indicate more berths will be called back to their permissible draughts.

“Ultimately, the safety of vessels must take priority for us as TNPA, which is why the harbour master took the safety precaution to review the permissible draughts of some berths earlier this year,” Motlohi noted.

TNPA was, meanwhile, pursuing various interventions to tackle the issue of diminishing draughts and was continuing with maintenance dredging and pushing forward its R2-billion dredging fleet replacement programme.

While the Impisi plough tug continued to dredge in the port, the short-term plan was for the Italeni grab hopper dredger to continue to dredge along the berth pockets of the DCT.

Italeni would remain in Durban until the port took delivery of a hired dredger dedicated to its dredging needs.

TNPA would also be taking delivery of its new Ilembe suction hopper dredger in December, which would be used for dredging larger areas, such as the entrance channels. 

TNPA had also received approval to build a new grab hopper dredger dedicated to the port, which should be delivered by the end of 2016.

“The long-term intervention will be TNPA’s project to deepen and lengthen the berths to cater for the bigger vessels now calling at the port.

“This project is expected to start next year and would enable the port to berth three big vessels rather than the two it was currently accommodating. This will immediately reduce the number of vessels waiting at anchorage, thereby improving port turnaround time,” said the authority.

An additional benefit was that the port would cease to be a tidal port, so that berthing and sailing would no longer depend on high tide. This would optimise the capacity of the port and improve the total vessel stay in South African waters.