Methane gas the source of the Joburg peak hour explosion
Independent contractors sent to assess the explosion in Joburg, found the gas explosion did not come from an Egoli gas pipeline. There was no gas leak and no gas rapture during the explosion, according to Floyd Brink, City of Johannesburg Municipal Manager. He was addressing a media conference in Johannesburg, on the 02nd August 2023, about progress regarding a recent explosion on Lilian Ngoyi Street (formerly known as Bree Street).
Brink also said the explosion was not caused by negligence by the electricity or any of the City’s departments, or any intentional action by individuals such as zama zamas (illegal miners) or terrorist attacks. He also said there were no people found living in the tunnel under discussion.
“The type of gas that fueled the explosion is lighter than air (methane), and is believed to have traveled through the service channel from Loveday to von Brandis street.”
An independent engineer who works with the City, said the Joburg explosion must have been between a threshold of between 5 and 15%.
Although inconclusive, preliminary findings suggest methane gas could have led to the explosion.
The eruption is believed to have started slowly and pressured upwards by 17 bar (1,700 meters per second) to have caused the explosion. The underground tunnel pressure was exacerbated by sealed manhole lids used to prevent cable theft.
The engineer also said if manholes were open, the incident would not have happened.
The source of methane could have been from overloaded sewer systems that needed to breathe. Another possible cause could have been from recent seismic activity from a recent earthquake in Johannesburg, a few days before the incident.
Although it is very difficult to locate the source of the methane, Brink says the area is safe and liveable.
Preliminary rough estimate for recovery is calculated at R178 million for the reconstruction of the tunnel and fixing the road. About R4 million was spent thus far.
Plans are to repair and upgrade the tunnel to suitable international standards, which will introduce elements like gas detection and alarm, sensors and monitors for employees.
Kabelo Gwamanda, the Executive Mayor of Johannesburg, thanked his dedicated team for tireless efforts in tackling the incident.
Although it is unclear how many other similar pipes and tunnels there are in the City that could cause a similar incident, Brink said, “as much as we are focusing on Bree Street, we will also focus on areas surrounding there, to have similar projects, to look at gas detection, and any other lessons learnt.”
The article was written by Nandi Mgwadlamba, editor of www.earthnews365.co.za
email: info@earthnews365.co.za
