Massive Durban explosion averted
Ship salvage experts saved city from a Beirut-type disaster
● Quick thinking and nerves of steel saved SA from a shipping disaster last month that could have been catastrophic, it emerged this week.
Salvage experts in chemical suits were airlifted into the burning cargo hold of a 190m ship to remove a smouldering chemical mix.
If the fire had not been contained, the cargo could have exploded while the ship was berthed in Durban port, causing an environmental catastrophe.
“Something went wrong inside that cargo hold — one chemical just started reacting and basically the fire started to spread throughout the hold,” said salvage master Richard Robertson.
“Then we had to move offshore and try to stabilise the situation,” Robertson said, adding that explosive gas had become trapped inside the burning hold.
“That became an explosive environment — if you opened and introduced oxygen to the Hold in that condition, there is a very likely possibility that it would result in an explosion. We’re still trying to confirm why and how it happened,” he said.
The high-risk operation was authorised and led by the South African Maritime Safety Authority (Samsa) in consultation with international maritime safety experts and local government officials.
However, the decision to dump the burning cargo offshore prompted public criticism despite the incident being declared an extreme maritime emergency.
Samsa said this week that dumping about 1,500 tonnes of the material was the only feasible option to save lives and avert a potential disaster.
“People need to understand that when we do something like that it is because we don’t have a choice,” said the authority’s Acting Chief Operations Officer, Capt Vernon Keller.
“In this case we didn’t want the issue to escalate. We were faced with a large vessel sinking, including all of the cargo and fuel oil, with potential loss of life.”
The drama began in October when a fire was reported aboard the Chinese-owned NS Qingdao, a bulk carrier berthed in Durban carrying a full cargo of chemicals used to make fertiliser.
Though the cause of the fire is still being investigated, it may be linked to steel coils loaded on top of the chemicals that damaged a cargo bag or caused enough heat pressure to ignite the volatile cargo.
Initial efforts to contain the fire failed, and the vessel was moved out of the port and anchored offshore. Maritime officials became jittery upon learning that the cargo included ammonium nitrate — the same substance that caused a massive fatal explosion in the port of Beirut.
“That is why we evacuated from Durban,” Keller said. “The idea was to kill the fire while offshore Durban.”
When salvage personnel opened the hatches the cargo became more unstable, forcing Samsa to transfer the ship to a safer anchorage in St Helena Bay on the Cape west coast.
“Durban was too exposed,” said Robertson. “It was a bold decision by Samsa and I must take my hat off to them — it was the best decision at the time.”
The next step was to deploy an international team trained to combat ship fires.
Team members wore chemical suits with oxygen cylinders and used hi-tech equipment including thermal cameras and gas meters to identify the chemicals on board.
“When you have numerous different chemicals reacting it is like a cooking pot,” said Robertson. “Individually these chemicals may be non-reactive, but if you put them under heat or mix them, you get a reaction — just like in the science classroom. We needed to stop that reaction.”
The team first isolated the fire in the aft (rear) cargo hold by using a cooling system and inserting an inert gas to replace the explosive chemical fumes.
They then had to transfer burning cargo into barges and skips brought alongside the ship. This involved using an excavator airlifted into the ship’s hold, and flying in two specialists from Europe to do the job.
The smouldering portion of the cargo was dispersed at an offshore site after consultation with scientific and maritime experts before the ship was escorted to Saldanha, where the rest of the cargo is being removed to a landfill site. Salvors are still monitoring the vessel’s condition.
Robertson described the operation as an extremely challenging one. “At one stage we were almost going to abandon the vessel,” he said.
Removing the burning cargo averted a much bigger disaster. “If those gases would have ignited an explosion could have threatened the whole ship, which could have sunk,” said Robertson.
Webber Wentzel Cape Town managing partner and maritime law specialist Gavin Fitzmaurice said SA had a history of successful maritime salvage operations. “The successful salvage of the NS Qingdao ... has shown how significant our adherence to international safety and emergency maritime procedures is,” he said.