Coronal capping design being completed for Namibian mine

10th July 2020 By: Tracy Hancock - Creamer Media Contributing Editor

Coronal capping design being completed for Namibian mine

TIME’S UP The coronal capping structures for two smokestacks had reached the end of their service life, and it was deemed necessary to replace them

Rope access specialist Skyriders is preparing to install a new coronal capping, with its design in the process of being finalised, for two smokestacks at a mine in Namibia.

The company secured the contract earlier this year, having had previous experience with this client in 2018 when it completed inspections of the operation’s cooling tower and smokestacks in 2018. Based on recent visual inspections, Skyriders was asked to help design and install a new coronal capping, explains Skyriders marketing manager Mike Zinn.

“A coronal capping, often a steel structure, sits at the end of a smokestack to protect the concrete or brick structure from lightning strikes. As smokestacks are often the tallest structures on mining sites, they often get struck by lightning.”

As the coronal capping structures had reached the end of their service life, it was deemed necessary to replace them.

Phase 1 of the project involved the design of a new capping, for which South African consulting engineering firm Nyeleti was subcontracted. The firm is familiar with the site, having assisted Skyriders with the initial inspections at the Namibian operation.

“The new design is similar to the old capping but will be easier to install using rope access. It will be designed to be light enough for us to lift with our rope access systems, but strong enough to withstand the tough conditions it will be exposed to on top of the stack.”

Nyeleti has also been briefed to ensure that the mechanism for bolting the capping onto the smokestack is more stable than that of the old capping, to prevent it from shifting when it is struck by lightning.

The finalised design will be issued to the customer, which will put the fabrication of the capping out to tender to Namibian companies. Once the capping has been fabricated, Skyriders will undertake the installation.

A six-person team of rope access technicians will hoist sections of the capping, which will be bolted together at the top and secured to the smokestack. Three technicians will be based at the top of the smokestack, while the other three will be based on the ground.

The customer has stated that the old capping is adequate for the time being, as it is currently the dry season in Namibia and no thunderstorms are expected.

“The hope is that by early September, before the country’s rainy season starts, we will be able to install the capping, as the restrictions on cross-border travel, owing to the Covid-19 outbreak, are expected to be less stringent than they are now,” says Zinn.

Impact of Pandemic

Having remained operational throughout the local national lockdown, the biggest challenge Skyriders has faced when servicing mining customers is the limitation on the number of people allowed in a vehicle during Level 5.

Zinn explains that the company has only a certain number of company vehicles that have the necessary permits to access customers’ premises. When sending a four-man team to one site, two vehicles were needed, resulting in the company incurring additional operating costs.

“Because many customers had reduced their staff complement, securing the permits for vehicles or extra employees was a massive challenge.”

A small part of the workday is still disrupted because of all the additional paperwork needed to operate during the pandemic, in addition to the sanitising of equipment and vehicles before and after use.

Owing to the nature of some contracts, Skyriders customers understood the use of additional vehicles, despite the extra cost to their account, while others were grateful that Skyriders remained operational during this time by obtaining the necessary permission from government.

After the lull in the second half of April, and early May, as companies prepared to comply with the various health and safety measures required by government, enquiries for Skyriders’ services have started increasing.

“Our industrial and mining customers realise that if production has not stopped, maintenance will inevitably have to take place,” notes Zinn.

He expects Skyriders’ Namibian project to keep the company busy, but points to enquiries from a gold mine in Mali, as well as Botswana diamond producer Debswana Diamond Company, about basic facilities maintenance.

Meanwhile, the advantage of using Skyriders’ rope access services amid the pandemic is the size of its teams, Zinn advances.

“To date, our largest team to work on a project has comprised ten individuals. We also work at height, far away from other contractors or a customer’s employees. Offering a range of services, from welding inspection to concrete repairs, we can safely assist clients during this difficult period using our existing working methods despite the current restrictions,” he comments.