On Friday evening, after 60 hours of speculation about the cause of the explosion in the Johannesburg CBD on Wednesday, city officials revealed the cause of the explosion – gas.
During a technical briefing, Johan La Grange, a civil engineer contracted by the city, said, “The reason is the gas, the reason is the gas.” Gas was leaking. The source of the gas is what we’re trying to determine – is it an old gas line, whether it’s from tenants or customers, or an Igoli gas leak [is unclear]. “
Daily Maverick I reported earlier on a preliminary investigation that indicated three possibilities: flaring of methane or natural gas, or the possibility of a gas pipeline leak.
Read more at The Daily Maverick: Detectives investigating three possible causes of the explosion Johannesburg Lilian Ngoyi Street closed due to safety concerns
By 5 p.m. on Friday, authorities could say with certainty that gas had leaked, and ruled out other possibilities.
This is a pure gas explosion. “We’re ruling out at this point anything to do with illegal mining or zama-zamas,” Lagrange said.
Wednesday’s explosion cut 450 meters of a four-lane one-way road, sending taxis and cars flying. One person died, and at least 48 were injured in the street collapse.
The gas line explosion was immediately identified as the main suspected cause — the gas lines run under the pavement but not under the road itself — but Egoli Gas, which operates the municipal lines, said afterwards that its lines were running at low pressure and were unlikely to cause an explosion.
On Thursday, the company said it had detected a small leak but confirmed it was unlikely to be the cause of the explosion.
“A small leak was detected on the service pipeline at the corner of Bree and Eloff on a 100mm pipe. We believe the crack in the pipe was caused by a road collapse. Our team is busy fixing the leak.”
Officials on Friday will not be tempted to comment directly on the possibility that the Igoli gas pipelines were the source of the explosion.
Work will start soon
City manager Floyd Brink announced the closure of the gas pipelines running under the site, meaning work to repair damaged infrastructure is likely to begin soon.
“By Monday, we expect all the manholes to be safe for us to open. You’ll remember we talked yesterday (Thursday) about some of the manholes that were welded on, so we’re working around the clock to make sure that even those of City Power or Telkom, we start opening those particular hatches and that will then help us get some level of ventilation.”
Tomorrow, Brink added, the teams will start fencing the area. “It is indeed a disaster site, but it will turn into a construction site very soon.”
Residents in many parts of the city have been without water and electricity since the blast, and this will likely be the case indefinitely.
Joburg City officials said Joburg Water will provide residents with water and washing facilities.
The city said electricity was likely to be back only by Monday.
“We are beginning to see a decrease in the presence of gas and we should be in a position to safely restore power and other services by Monday, at the latest.”
Read more at The Daily Maverick: Johannesburg emergency appeal to engineers and gas detection experts after CBD explosion reveals huge skills gap
Johannesburg Water has deployed 25 chemical toilets, five fixed and four mobile water tankers in the area to support residents. The chemical toilets will be serviced three times a week. Once the site is secure, Johannesburg Water will deploy CCTV technology into the underground piping systems to ensure there are no more unknown damages before services resume.”
Meanwhile, businesses in and around the area remain closed following the city’s decision to cordon off Bree Street indefinitely.
Daily Maverick He spoke to the many taxi drivers and retail workers who expressed concern that they would not be able to make a living as a result of the lockdown.
“Some of us in the retail business get hourly wages, so this is really affecting us because we won’t have income for a long time, it seems,” said district retail worker Sepongil Dlamini.
Read more at The Daily Maverick: Residents described Joburg’s explosion – ‘I felt my gut grow cold with fear’
If the street remains closed for the next week, for Dlamini—who is paid a weekly wage—it means “I won’t be able to buy food, and if it continues for another week, I may not be able to pay the rent.”
And not only small businesses are affected, but also the offices of the Conciliation, Mediation and Arbitration Authority, which announced that they will remain closed in order to preserve the health and safety of employees and clients.
structural integrity
Professor Felix Okonta, Head of Geotechnical Research and Pavement Engineering at the University of Johannesburg, stated earlier Daily Maverick Although no physical structural damage was visible on the buildings near the scene of the accident, there was no doubt that the surrounding buildings were affected by the vibrations of the explosion, adding that structural integrity tests are required.
The score will then determine whether or not it will remain stable.
“To me what we have to worry about is the stability or the structural integrity of the buildings more than the explosion…the cracks we see today will not be the only cracks we see in years to come.”
However, the authorities believe there will be no need for mass evacuations.
“There is no indication that buildings or foundations were damaged by the explosion, which took place in the middle of the street,” said La Grange.
With the technical team now in full charge of the operation, after spats by politicians, Brink said teams will work around the clock to ensure the business center is running.
But this will not happen overnight. “It will take a few weeks, a few months, but the teams are ready.” DM
