Gautrain Explosives and Detonator Requirements
The requirements in terms of the contract were an initiation system that was safe, user friendly and reliable; an explosive delivery system that was quick, efficient and flexible to adapt to the sites’ requirements; logistics for emulsion non-explosive (storage constraints); an initiation system that would minimise air blast and ground vibrations (environmental constraints); and technical support and advice on blasting requirements.

To minimize airblast and vibrations the Smartdet®, fully programmable electronic initiation system is used for the shaft sinking and the QuickShot™ is a pre-programmed electronic initiation system used for the tunneling.

The QuickShot initiation system has been proven with features as inter-hole flexibility; pre-blast testing of all detonators; immune to electromagnetic radiation and stray currents; and improved blast cycles due to better advance, fragmentation and cleaning cycle.

AEL’s Underground Bulk System technology and DetNet’s Electronic initiation systems combine to optimize safety, while dramatically improving blasting efficiencies in a variety of tunneling and shaft sinking applications.

Considering the construction duration of the project, the consumption of the electronic detonators is between  15 000 to 20 000 detonators per month; a typical end takes anything between 100 and 150 detonators in one blast whether it’s a 3.5 m or 5.8 m advance respectively, depending on the size of the tunnel. Marlboro Portal has achieved a clean advance of 5.8 m of the 2km+ with a tunnel dimension of 12m wide and 8m high.

The success of this project is a combination of application and a product that is robust in terms of advanced technology. The Tunnel – drilling and blasting activities will end during 2009 – the final phase for the conventional tunneling using explosives and electronic detonators.