Container stack collapses put vessels and crew in danger > 자료실

Container stack collapses put vessels and crew in danger

Following the increased issue of container stack collapses, Standard Club shed light on the causes and the solutions of such incidents, highlighting that collapses put vessels, their crews and the environment in danger.

Safety | 27/01/21

According to the club, despite several major advances in standards and procedures, collapses are still an unsolved matter within shipping industry.

"These incidents can often result in significant financial losses to the container industry and their marine insurers, sometimes with hefty fines for clean-up costs."

...Standard Club stated.

In light of the situation, the club reminds to ships’ officers, operators and crews, various factors that can contribute to container stack collapses, and how they can be avoided by taking greater care and attention during loading, securing and passage planning and when underway at sea.

Among others, the club highlighted the following:

• Bigger vessels: As Standard explained, due to the large beams of post-Panamax giants and the relatively large metacentric heights (GM), the vessels are very stable and therefore stiff. Consequently, under very high rolling accelerations when the weather deteriorates, this generates similarly high loads in the container lashing and securing gear.

• More powerful ship engines: Increasing commercial pressures means that container ships usually have to keep to very tight operating schedules, particularly in the liner trade, and they need to be as fully loaded as possible. As a result, they have increasingly powerful engines, not only to provide the high speeds required but also to enable speed to be maintained during bad weather.

• Higher wind loading: It is known that almost all container stack collapses at sea occur in rough weather with strong winds. Therefore, when fully loaded, the deck stacks on modern container ships present additional windage areas over 25 m high. Combined with large freeboards, the stacks act like giant sails to amplify a ship’s motions as the weather deteriorates, further adding to lashing and securing loads.

• Improper container stowage: The stack weight on a container ship is the total weight of all containers and their contents in the tiers of a particular stack added together. The ship’s cargo securing manual states the maximum permissible stack weight for each stack. Deck stack collapses often occur in those bays where the stack weight was exceeded.

"Despite proper packing of the cargo into containers, correct weight declarations, and proper stowage and securing on ships, factors ranging from severe weather and rough seas to more catastrophic and rare events like groundings, structural failures and collisions can result in containers being lost at sea."

...the club concluded.