Climate change partly behind port congestion, says Transnet
● Transnet has blamed climate change for Cape Town being one of the world’s worst performing ports — and it may have a point.
Recent scientific findings suggest the weather along the Atlantic seaboard is getting windier, the swell bigger and the waves longer, all of which affect Cape Town’s ability to berth ships and operate cranes to offload large containers. And it’s not just Cape Town — stormier weather is having an impact along the entire coast.
The issue was raised this week by Cape Town port manager Rajesh Dana while addressing exporters about port congestion partly caused by crumbling infrastructure — and, Dana said, partly by the weather. An increase in long wave action — small long-period waves caused by wind — had prompted Transnet to buy special equipment needed to stabilise ships berthed inside the port.
The arrival of 52 new hydraulic tension mooring units had been delayed by port congestion elsewhere in the world — they were due to arrive last month. Transnet currently only has six of the mooring units, at Ngqura and Cape Town ports. “We are finding that climatic sea conditions are changing way beyond expectation,” Dana said, adding that winds were becoming more unpredictable. “These phenomena are not unique to Cape Town,” he added.
Transnet has contracted the Council for Scientific and Industrial Research (CSIR) to determine long-term weather trends, with specific reference to the port.
Senior South African researcher Dr Neville Sweijd, director of the CSIR’s Alliance for Collaboration on Climate & Earth Systems Science, this week confirmed a study on extreme wind in the Port of Cape Town, which coincides with a broader CSIR study of climate change impacts on ports in general. He said the research would benefit port operations “in the short term in predicting and managing wind dynamics — specifically on decision-making regarding if and when and for how long to close or open the port”.
Some concerning recent scientific findings include:
● Wave height has increased significantly at two locations near Saldanha Bay since the 1960s, from 4.1m in the 1960s to 6.1m in the 2010s and 6.24m in the past two years;
● Cape Town port has lost an average of 1,200 hours a year of operations due to extreme wind — an increase on previous years and well above the recorded average disruption of 800 hours;
● The South Atlantic has seen a marked increase in “storminess” — extreme waves and storm surges — associated with a southward shift of “storm tracks”; and
● +The coast is increasingly affected by “long waves ”— almost imperceptible long wave lengths up to several hundred metres that are hugely disruptive to ship berthing.
A group of leading scientists is looking specifically at climate change trends to better predict possible impacts — on everything from ports to agriculture. Sweijd said research findings suggest extreme weather events are also on the increase, which is a predicted side-effect of climate change.
“We have had a few interesting big swell events including the September storm surge and some spectacular swells sometime last year or the year before. I guess the message is, as we experience more volatility and variability on extreme weather and wind, we can expect to see more powerful impacts which generate waves. Precisely how these waves will impact our shore (and ports) remains to be seen.
“This last winter was of course quite special — so when we have cut-off lows hanging about in one place we will see wave generation of a range of wave lengths and heights including long waves. This is a research question.”
The port has a 90km/h wind limit, above which all operations must cease. Huge volumes of South African fruit, mostly apples and oranges, are shipped overseas in late summer on refrigerated “reefer” ships, with the peak fruit export season beginning in January. Transport delays are costly and affect revenue on both sides of the supply chain.
Speaking to exporters this week, Dana said the climate change impact was aggravating human errors at the port, where recent interventions have significantly eased congestion — unlike in Durban where a major container backlog persists. He said maintenance of critical equipment and capital investment remained areas of concern: “We are in a perfect storm — we are alive to this fact. We are well aware of the challenges. Our approach though is to co-create solutions to the challenges.”
Earlier this year Cape Town port plumbed new depths when it was ranked 344th out of 348 ports in a World Bank Port Performance Index. But Transnet says it is already seeing improvements thanks to its hydraulic tension mooring units, with the next batch expected to further improve ship berthing.