Rope-access specialist Skyriders removed coal hang-ups and conducted high-pressure washing on the internal silo surfaces at one of State-owned power utility Eskom’s silos. The project started in mid-July and was completed that same month.

Removing the coal hang-ups required two teams of experienced rope-access technicians to use breakers and other mechanical means.

“The teams worked systematically to ensure that only small sections of the hang-ups [broke] - free at a time. If large pieces break free . . . it can cause damage. For instance, if they were to fall or block the hoppers, it can result in additional problems,” explains Skyriders marketing manager Mike Zinn.

The team spent five days and five nights removing the coal hang-ups, with the high-pressure washing of the internal silo taking three days. All hang-ups were removed without incident.

Zinn highlights the confined space, dust, potential gas and dust explosions – combined with the sheer volume of the coal hang-ups that had to be removed – as some of the challenges.

“We mitigated these challenges by having two shifts working day and night. We also used rope access to help achieve the goal in the shortest time available.”

Each shift comprised a five-person rope- access team, with a three-person confined-space standby rescue team during the project’s peak, with 16 employees working in total.

“In addition to the confined-space rescue equipment and gas-monitoring equipment, only breakers and spades were used to remove the coal. Thereafter, high-pressure washers were used to wash the silo’s internal surface,” says Zinn.

He adds that a Ferno Arachnipod – a versatile modular total edge management system – was used to ensure rapid extraction of the team in case it was required.

Zinn highlights the importance of employing a comprehensive and safety- focused solution for this type of task, as personnel who remove coal hang-ups and conduct high-pressure washing inside silos often do not have the necessary training, specialised equipment or confined- space standby and rescue support. He attributes this to companies often regarding the removal of coal as a simple task.

“The sheer size of the silos, the volume of hang-ups, the inherent dangers of the coal and the confined space make it an extremely dangerous place to work and, when the situation takes a turn for the worse, you want a well-equipped, well- trained and professional team doing the work,” he concludes.