Problematic toxic cargo headed for the bottom of the sea, announces SAMSA

Photo courtesy of Dr Holling

UPDATE:

Pretoria: 17 January 2022

The story below has elicited huge interest from a broad range of people across several sectors. Top most has been concern about the decision to dump the cargo of the vessel at sea, as annouced in the article. In response, SAMSA’s Deputy Chief Operations Officer, and acting Chief Operations Officer, Captain Vernon Keller has since provided more detail about the development during a radio interview with Cape Talk Radio last week.

Click on the following link for the interview (+- 6 minutes).

Pretoria: 13 January 2022

A problematic water reactive cargo approximating 1500 tonnes laden on a vessel in St Helena Bay on the west coast of South Africa will be formally, finally dumped at sea; the South African Maritime Safety Authority (SAMSA) announced in Pretoria on Thursday.

According to SAMSA, this will be just over two months of the country working tirelessly around the clock to safely manage the unstable chemical cargo since the encounter with its bearer vessel, the NS Qingdao, in Durban last October.

Since then, the vessel was shepherded under a watchful eye to a safe containment terminal in St Helena Bay on the Atlantic Ocean seaboard.

In subsequent updates about the management of the vessel, SAMSA described its cargo as consisting of “a mixture of Sodium Metabisulphite, Magnesium Nitrate Hexahydrate, Caustic Calcined Magnesite, Electrode Paste, Monoammonium Phosphate, Ferrous Sulphate Monohydrate, Zinc Sulphate Monohydrate, Dicalcium Phosphate, Sodium Sulphite Anhydrous and Calcium Chloride.”

On Thursday, in the statement in Pretoria announcing the latest development; SAMSA said: “SAMSA and its partners are continuing with the salvage work on the NS Qingdao. The NS Qingdao was evacuated from the port of Durban on 23 October last year after her cargo suffered a chemical reaction and released toxic fumes into the atmosphere.

“The vessel is currently anchored off St Helena Bay and an emergency dumping permit has been obtained from the Department of Forestry, Fisheries and the Environment to dump the reacting cargo at sea.

“Approximately 1500 tonnes of cargo will be dumped 250km from the closest point to land and in excess of 3000m of water. The dumping operation is expected to be concluded on 25 March 2022.

“To date more than 1000 tonnes of the cargo has been taken out of the vessel and it is expected that the remaining hotspots will be removed and dumped by 15 March 2022.

“The vessel has no obvious structural damage, and she will return to the closest port after the dumping operation is complete and her cargo is stabilised. An investigation will also be conducted to determine the reason for the cargo reaction .

“Structural specialists will also conduct an assessment to ensure that the integrity of the vessel is intact before allowing her to sail onward to her destination.

“The tug Umkhuseli continues to act as a safety stand by vessel. The operation is weather dependent to ensure that the highest levels of safety standards are maintained throughout the operation.

“The owners, insurance and salvors continue to work with the South African authorities on this matter,” said SAMSA

End

Specialist equipment procured from Europe to evacuate unstable chemical cargo off vessel at St Helena Bay: SAMSA

02 December 2021

The procurement and arrival in South Africa next week of an Inert Gas System and a specialist excavator operator from Europe is expected to relieve pressure and provide enhanced safety to management efforts of transferring an unstable chemical cargo off a constrained vessel currently docked in St Helena Bay.

That is according to the South African Maritime Safety Authority (SAMSA) in a statement in Pretoria on Thursday confirming the docking yet again of the Marshall Island flagged bulk carrier, NS Qingdao, back at St Helena Bay on Tuesday, after days spent off shore due to its unstable chemical cargo.

The saga with the vessel, according to SAMSA, began on 23 October 2021 in Durban where it had docked to offload its chemical cargo, but had to be sent back offshore and rerouted to St Helena Bay after her cargo suffered a chemical reaction, releasing toxic fumes into the atmosphere.

Photo courtesy of MarineTraffic.com

According to SAMSA, redirecting the bulk carrier, now under constant escort, to St Helena Bay on the country’s west coast (Atlantic Ocean) was intended to provide it with protected anchorage, “with the advantage of being in close proximity to the Vissershok waste deposal site where the cargo could be safely discharged and neutralised.”

However, with stormy, wet weather unrelenting, said SAMSA: “Last week (25 Novembe)r the vessel was instructed to sail offshore (again) under tow to help ventilate her No3 cargo holds after the hold was closed due to a change in weather conditions causing an increase in hot spots in the hold and fumes to enter the engine room through the engine room vents.”

In the meantime, said SAMSA that all non-essential personnel were removed as a safety precaution, with only a minimum crew onboard. In the intervening period, plans were made to procure a special Inert Gas System and a specialist excavator operator from Europe. SAMSA said the Inert Gas system would be used to blanket the cargo with an inert gas to prevent any further reactions in the cargo.

However, the discovery of and an announcement in South Africa about a new Covid-19 variant, Omnicron, which almost immediately sent several countries abroad in a tailspin of panic, followed by the closure of borders and bans on international flights to the country, “delayed operations slightly,” said SAMSA, adding that the salvage crew was, however, “optimistic” that the Inert Gas System would arrive in St Helena Bay by Tuesday next week (07 December 2021).

A MarineInsight.com illustration of an inert gas system plant.

MarineInsight.com contextualises the use of an inert gas system as follows: “Inert gas system is the most important integrated system for oil tankers for safe operation of the ship. Inert gas is the gas that contains insufficient oxygen (normally less than 8 %) to suppress the combustion of flammable hydrocarbon gases. The inert gas system spreads the inert gas over the oil cargo hydrocarbon mixture which increases the lower explosion limit LEL (lower concentration at which the vapours can be ignited), simultaneously decreasing the Higher explosion limit HEL (Higher concentration at which vapour explodes).

“When the concentration reaches around 10%, an atmosphere is created inside the tank in which hydrocarbon vapours cannot burn. The concentration of inert gas is kept around 5% as a safety limit.”

Meanwhile, in Pretoria on Thursday, SAMSA further reiterated its earlier assurance that the toxic fumes emitted from the vessel do not pose any danger either to humans or the oceans and coastline environment. Providing specific detail of the bulk carrier’s water sensitive and reactive chemical cargo, SAMSA said: “SAMSA would like to assure the public that this is a controlled event and neither the environment nor any person is at risk at this time and that all safety precautions are taken to prevent the situation from escalating.

Of the cargo’s nature, the agency said: “The bulk cargo consists out of a mixture of Sodium Metabisulphite, Magnesium Nitrate Hexahydrate ,Caustic Calcined Magnesite, Electrode Paste, Monoammonium Phosphate, Ferrous Sulphate Monohydrate, Zinc Sulphate Monohydrate, Dicalcium Phosphate, Sodium Sulphite Anhydrous and Calcium Chloride.”

With the recall of the vessel to dock at St Helena Bay on Tuesday, said SAMSA: “The cargo is being discharged into skips to remove all hot spots in the cargo hold to help neutralise the chemical reaction and gases under the watchful eyes of experienced salvors and chemical experts.

“The first two skips were discharged yesterday morning in the care of SPILLTECH for transportation to Vissershok under controlled conditions. SAMSA would like to reaffirm that there is no immediate risk to any person ashore and that all persons involved in the operation onboard is using all the required personnel protective equipment.”

However, just to be sure, extra measures undertaken since the rerouting of the vessel from Durban to St Helena Bay have included the constant watchful eye of a tug UMKHUSELI that, according to SAMSA “will remain on site to act as a static tow while the vessel is at anchor and ensure that any toxic gases are blown offshore during the operation.

“The ship owner is cooperating with SAMSA, DFFE, TNPA, Salvage Team and local authorities.SAMSA would like to assure the public that this is a controlled event and neither the environment nor any person is at risk at this time and that all safety precautions are taken to prevent the situation from escalating,” said the agency.

End.