Portnet begins tests on 'world-first' wind wall for CT

Honeycomb structure will double as reefer storage, writes Ray Smuts THEY LAUGHED at Christopher Columbus's world is round pronouncement and were cynical of John F Kennedy's vision of putting a man on the Moon. What will the sceptics say, one wonders, about man's attempt-in-the-making to harness the Cape's vexing south-easter, the Cape Doctor, with its penchant for causing general mayhem ranging from disrupting shipping to blowing hapless little old ladies off their feet for six months each year. For several years now the Dutch and South African governments and their respective consultants have been looking at ways to address the problem of wind in the Port of Cape Town. Wind walls affording a measure of protection to shipping are already in place in the Ports of Le Havre and Rotterdam. But thanks to Dutch engineer Hans Wajga, a crane specialist, a wind wall with a difference - believed to be a world first - could also bring some relief to Cape Town if tests to be conducted by the Council for Scientific and Industrial Research (CSIR) from the end of July prove conclusive. (Portnet and the CSIR are about to finalise an agreement in this regard). What makes this proposed wind wall so different is that it will serve the dual purpose of minimising wind and acting as a storage facility for reefers or other boxes. Billy Cilliers, Portnet's manager for planning and development in Cape Town, says the initial Dutch study points to a honeycomb, rack-like, structure of around 30 metres high and about 590 metres long capable of accommodating 1 000 five-high cube capacity reefers. "This Vertical Reefer Stack (VRS) will provide us with an optimised reefer stacking solution as opposed to the present scenario where we are experiencing severe stacking capacity problems in the port." (Capacity is about 400 000TEUs and the port is nearing that having handled 370 000 TEUs last year). As to benefits that could accrue to Portnet from VRS, these would include reducing the wind in at least two container berths (probably 601 and 602) resulting in faster turnaround, very effective reefer storage and income from such storage. (Wind delays in the Cape winter months of October to March range from 10% to 30%). According to Cilliers, engineer Wajga's study points to a possible 20-25% decrease in wind from 80km/h, the maximum at which cranes are allowed to work in Cape Town. The CSIR's Adam Goliger, an expert on wind, says: "Its effectiveness will depend on many factors like size, height, angle, positioning and cladding, but my gut feel is that the wind force could be reduced by between 20 and 30%."