Officials reveal methane gas was the cause of explosion downtown Joburg

Officials reveal methane gas was the cause of explosion downtown Joburg
At a Wednesday media briefing, Floyd Brink, the city manager of City of Johannesburg, disclosed this.

According to an inquiry, the tragic Lillian Ngoyi Street (formerly Bree Street) explosion that shook the center of Johannesburg last month was caused by methane gas.

One person was killed in the explosion, numerous people were hurt, it damaged the local infrastructure, and services were interrupted.

Since methane is lighter than air, it often rises. From an unidentified source, it moved up the entire length of the service tunnel to the tunnel's crest close to Von Brandis Street. Why did we not see any fire has long been a mystery.The threshold for low explosive levels is somewhere between 5 and 15%. Anywhere from 5 to 15% will result in an explosion, and anything over 15% will start a fire.

"This one was an explosion since it was between the threshold of between 5 and 15%. We could not detect any evidence of black scorch from a fire as we drove our drones inside those tunnels, he claimed.

Brink said, "Several other potential causes, such as a gas leak, illegal underground mining, or negligence, were ruled out by the investigation."

The city manager stated that the projected cost of the necessary repairs to restore and rebuild the area is presently more than R100 million.

"At this time, our estimated estimate is now around R178 million, and that figure is based on work that has already been completed but is based on conceptual concepts. We will signal as we get closer with specific plans. Depending on the designs we come up with, that sum might rise.

"That is a preliminary look at what it will cost us for the road, what it will cost us for any other infrastructure damages, and also to reconstruct that particular tunnel," added Brink.

He said that the City of Johannesburg spent over R4 million on "professional experts, services, the cordoning off of the site, technology that we've used, and the provision of temporary relief" in the wake of the explosion.

According to Brink, the city has drawn several conclusions from the incident and steps are in the works to prevent a repeat.

To lessen the possibility of these explosions being severe, the tunnel designs will be updated based on the most recent international standards for tunnels. For all staff members working in the tunnels, we will also implement continuous gas detection, alarms, sensors, and monitors.

"We would need to improve to make sure that we use technology as we move forward with the reconstruction and upgrading of these specific regions. Our tunnel designs will be based on internationally recognized standards that are pertinent to tunnels and explosion prevention with unintentional release of combustible gas in cavities and/or tunnels, the man stated.

Brink emphasized that other projects will also start at other streets in the region to "look at gas detection and any other issues" in addition to the work to secure the tunnel being focussed on Lillian Ngoyi Street.

(With help from a press release from the South African government)
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