Africa’s longest underground tunnel with three stations that cost £2.6bn to build | World | News

A 9.6-mile-long underground tunnel in Africa is nothing less than a construction marvel.

Built at a cost of a whopping £2.6 billion ( $3.3 billion approximately), the Gautrain rail tunnel is Africa’s longest tunnel. 

A first-of-its kind in Africa, the tunnel includes three underground stations: Johannesburg Park Station, Rosebank Station and Sandton Station.

The Gautrain Line features an extensive and sophisticated tunnel network that plays a crucial role in connecting key areas in Gauteng, South Africa. 

The tunnel was completed using both tunnel boring machines (TBMs) and conventional drilling and blasting methods. 

It alone significantly enhances the connectivity between central Johannesburg, Sandton, and other strategic hubs.

The Gautrain project itself spans an 80-kilometre route and was designed to alleviate road congestion while providing a modern and efficient rapid rail system. 

The tunnel infrastructure includes seven emergency access shafts to ensure safety, along with safe havens at critical points for passenger protection in case of emergencies. 

These safety measures, combined with state-of-the-art track geometry and condition monitoring systems, ensure that the Gautrain network operates smoothly at speeds of up to 160 km/h.

The project’s construction and tunneling phases were a major engineering feat, completed in phases between 2010 and 2012. 

The integration of underground tunnels allows the Gautrain to bypass dense urban areas, offering commuters a seamless travel experience from Johannesburg to Pretoria and OR Tambo International Airport.

Africa is home to many long tunnels and these tunnels across the continent serve a variety of purposes, including waterways, railways, and road networks.

Constructing these tunnels is a highly challenging task, made even more difficult when both ends of the drilling need to align precisely while maintaining a line of sight. 

Traditional tools like compasses are ineffective due to the absence of magnetic fields, and GPS cannot be used underground. As a result, engineers and construction workers face significant obstacles, relying on advanced techniques and precision to ensure these tunnels are successfully completed.