The incident reported below occurred while discharging containers from a vessel at anchorage.
On the day of the incident, containers were being discharged from the ship using the ship’s crane onto a barge that lay portside alongside the vessel. The container in question was discharged/landed onto the portside pontoon of the barge. The next container was lifted by the ship’s crane and in the process of landing the container onto the barge, hit the container in question. At the time of the incident the barge had a 10 degrees port list and had no side rails in place. The impact caused the container in question to slide over the pontoon of the barge and overboard. The container sank to the bottom of the bay which had a charted depth of 30 metres. The ship’s cargo and dangerous cargo manifest indicated that the container in question was a 20-foot container said to contain 20,000 Kgs (200 drums of 100 kg each) of sodium dithionite (UN No. 1384, IMO 4.2).
According to the IMDG code, sodium dithionite is liable to heat and ignite spontaneously when exposed to air and to emit sulphur dioxide. Furthermore, it is a requirement to keep sodium dithionite as dry as reasonably practicable.
Container placed on a flat barge being towed to a remote location for inspection.
The vessel and the barge were shifted away from the area and the position that the container had sunk was marked with marker buoys. The port contingency team was immediately mobilised. It was suggested by chemical experts that the most crucial period during any salvage operation would be when the container was taken out of the water. A comprehensive contingency plan was formalised which included chemical experts, divers, fire-fighters and a first aid team. A team of divers from the coastguard hooked up and hoisted the container by a winch fitted on the deck of a barge. The barge was then towed away from the traffic-dense area of the bay with the container still submerged in the water. With fire-fighters standing by, the container was hoisted out of the water, placed on a flat barge and towed to a remote location for inspection.
Irrespective of whether cargo is being loaded or discharged onto the pier or onto barges, it is imperative that a comprehensive and thorough risk assessment is carried out.