A combination of rope access and the use of an Elios collision-tolerant drone allowed a prominent colliery near Delmas in Mpumalanga to complete a routine silo inspection in record time, not only minimising downtime, but ensuring the health and safety of all involved in the fast-track project.

The project took place over a routine ten-day shutdown at the colliery at the end of July, which posed an immovable deadline for the inspection work to be concluded, Skyriders Marketing Manager Mike Zinn explains.

“Not only was our scope of work manifold, but the time pressure was immense,” Zinn adds. Skyriders deployed a 21-person team, consisting of a two-person drone team, 18 rope-access technicians, and an inspection manager to oversee the successful completion of the project.

The first phase was to deploy the Elios collision-tolerant drone to ascertain the extent of the coal build-up within the silo, which then gave another contractor the necessary information to plan to remove the coal as quickly and effectively as possible.

The Skyriders’ rope-access team would then re-enter the cleaned-out silo, wash all the internal walls using a high-pressure cleaning system, and then carry out a detailed visual inspection in order to determine any defects in the concrete that required lining repair.

The presence of various factors such as moisture in the silo causes the coal material to bind and adhere to the walls in a compacted form. This build-up can restrict coal flows and place undue stress on the silo walls, as well as clog silo outlets.

Such was the extent of the coal build-up that the Skyriders team itself jumped in to assist when the contractor responsible for removal of the initial coal build-up began to experience complications. “We were ultimately responsible for the entire scope of work. It is safe to say that our timely and effective intervention saved the day for the colliery,” Zinn comments.

Not only was the project completed within the tight timeframe, the visual inspection revealed that no additional concrete repairs were necessary. Within 12 hours of the successful completion of the inspection, the silo was up and running again.

“This project was a particular challenge, as it combined confined-space work with work-at-height. Each of these disciplines has specific health and safety protocols that have to be adhered to at all times. Here our use of a drone, combined with rope access, was the ideal solution to meet the client’s requirements as quickly and as cost-effectively as possible,” Zinn elaborates.

While initially sceptical about the application of hi-tech drone technology in such an arduous and potentially dangerous environment, Zinn says the colliery manager was won over by the highly successful outcome.

“The underlining message is Skyriders does not use technology just for technology’s sake. It is highly unlikely that this project would have been completed within the stipulated timeframe without the combined use of drone and rope-access services,” Zinn concludes.