The Centre for Scientific and Industrial Research- (CSIR-) hosted Alliance for Collaboration on Climate and Earth Systems Science (Access), along with other CSIR researchers and partners, have noted the wind aberrations in the Port of Cape Town.

The team is actively assessing the economic impacts of these wind disruptions while supporting the Transnet National Ports Authority (TNPA) and its clients with short- and long-term wind predictions.

At the peak of the fruit picking and packing season, Cape Town’s gusty summer southeaster typically swirls over and around Table Mountain and Devil’s Peak. It is normal for that strong Cape Doctor wind to then blow down to the bay, focusing, as if through a lens, onto container ships and cranes moving in the port.

It is unusual, however, for the port to experience extreme winds that are more frequent and intense than before.

“This is our concern, especially when demand for marine services in the port is increasing,” Access programme director Dr Neville Sweijd says.

If these amplified harbour winds exceed about 80 km/h, port operations need to shut down to avoid safety risks from swinging containers and the potential collapse of cranes. 

Sweijd says such wind disruptions are causing logistical headaches and financial losses for fruit exporters. Over the last few years, the Port of Cape Town lost, on average, 1 200 hours of operational time a year as a result of extreme wind disruptions.

"Occasionally, fruit companies have to put their fruit on a truck and get it to Durban so that they can get it to their market on time,” he points out.

“We provide them essentially with weather parameters that inform their port operations,” CSIR engineer Vuyo Ndayi adds.

Ndayi specialises in ocean monitoring in ports. He says the CSIR’s wind anemometers and sensors provide wind speed, wind direction and wind gust data that allow for hourly and daily operational decision-making.

“We need to get a good handle on understanding the wind, how it will trend going forward and what measures we can actually then put in place to try to reduce the effects on port operations,” TNPA technical director Magenthran Ruthenavelu explains. 

He adds that the research will inform potential changes or additions to the port layout and structures to divert wind away from the operational area of the terminals.

Fruit exporter Fruitways spokesperson Zelde Kennedy says the data will also help exporters plan around anticipated wind delays.

“It will definitely have an impact on our cost, and I think it will be better for the whole industry,” she says.

Sweijd says the extreme wind disruptions are linked to climate change.

For the windy Cape Town port, Ndayi says, long-term predictions and climate modelling will try to answer the question of how the wind will change.

“Is it going to become worse? Is it going to become better? Are we going to see it outside of the spring and summer months, and how is that going to affect how things are run in the port?” he muses.

The Access programme is supported by the National Research Foundation and the Belmont Forum.