Maximising ventilation air flow

Kiruna in Arctic Sweden is one of the largest underground mines in the world. In a recent project to boost its output of iron ore, a ventilation shaft with a 400 m vertical drop and a cross section of some 3×4 m needed to be scanned to know its shape. 3D Laser Mapping together with AF Infrastructure AB developed a solution to scan this vertical ventilation system.

Due to the scale and nature of the project area, problems were faced when mapping the shaft. Previous methods of gathering as-built data involved a platform that was moved manually between set ups, which proved to be expensive and time consuming. 3D Laser Mapping was approached by AF Consult, with the hope of finding a faster solution to the problem.

A system was devised that used ZEB technology, combined with the ZebRA (Remote Actuator), a device that can be used on a remotely controlled platform. This allowed the ZEB1, which is normally handheld, to be mounted to a metal cross frame and lowered into the mine shaft. This increased the mobility and versatility of the solution.

To execute the initial scans for this new project, the ZebRA system was lowered into the vertical shaft at about 1.5 km/h. This allowed for a depth of 350m to be scanned in both directions in only 30 minutes.

‘If you use the technology correctly and know what you are doing this is most definitely a game changer. After a trial period…we have refined our method and feel confident about what we can deliver to our clients.’ Lennart Gimring, Senior Consultant, AF Consult – Sweden.

After repeat trials and testing of this new system, a methodology was devised for the most successful use of the ZEB1 scanner in the vertical shaft, reducing the length measured per scan to 100 m for improved accuracy. AF Consult is constantly refining the technique, resulting in a growing confidence in the solution.