AMSA published a recent notice regarding the proper stowage and securing of cargo containers. AMSA aims to remind operators of the importance of stowing and securing cargo containers, and the potential danger to container ships navigating near intense low-pressure systems that occur off the east coast of Australia.
The effects of East Coast Lows
ast Coast Lows are intense low-pressure weather systems that occur off the east coast of Australia. These systems are also referred to as complex lows or Tasman lows.
Strong southerly winds, when combined with an easterly swell, can create extreme wave conditions where container ships are at risk of losing cargo overboard. In such incidents, swell size and interval may lead to excessive or even parametric rolling resulting in extreme acceleration forces on container stacks.
Guidance for avoidance of parametric rolling states:
One way of reducing excessive accelerations is for the master, as far as possible and practicable, to plan the voyage of the ship carefully so as to avoid areas with severe weather and sea conditions. The master should always consult the latest available weather information
Cargo Securing Manual
Masters and deck officers must be familiar with the contents of the Cargo Securing Manual including container securing requirements, maximum container stack masses and permissible vertical sequences of masses within container stacks.
Exceeding the mass limits defined in the Cargo Securing Manual may result in the destruction of lashings and fittings or the collapse of individual containers due to excessive acceleration forces in heavy weather.
Correct application of securing devices
AMSA has recently found instances of twistlocks designed for vertical layering between containers used as base locks even though they were colour coded.
On other occasions, AMSA inspectors have found loose or insufficient lashing arrangements. SOLAS requires cargo to be secured ‘throughout the voyage’ to prevent loss of cargo overboard.
The Cargo Securing Manual specifies the types and correct application of cargo securing devices provided on board the ship. The master is ultimately responsible for verifying securing arrangements and should ensure that officers delegated to carry out this important task are fully aware of the contents of the Cargo Securing Manual.
It should be noted that overtightening can cause damage to lashing points and lashing rods.
Australia expects cargo to be carried in full compliance with the vessel’s approved Cargo Securing Manual and in accordance with the requirements of the SOLAS Convention.
Due to the risk to Australia’s marine environment AMSA will continue to direct additional focus on container stowage and securing arrangements during forthcoming port State control (PSC) inspections in Australia.
If, during a PSC inspection, evidence is found that:
- The weight distribution or stack weights are not in compliance with the approved Cargo Securing Manual; or
- Crew are unfamiliar with the approved Cargo Securing Manual; or
- The securing arrangements are not in accordance with the approved Cargo Securing Manual (throughout the voyage); or
- The securing arrangements are not maintained or not in accordance with the approved Cargo Securing Manual; or
- The Cargo Securing Manual does not adequately cover the cargo being carried.