TT Talk - Containers do not just fall from the sky
TT Club has previously reported on incident experience whereby containers have dropped from lifting equipment during handling operations. Recurrence appears, as previously, to have nothing to do with the intrinsic quality of the corner castings. The reliability of the lifting process is critical.
A further instance of a container falling from a spreader during handling operations is worrying. Information entered the public domain in a report to the International Maritime Organization (IMO) following an incident in Canada in 2006. That report did not establish the precise reason why the reach stacker twistlocks disengaged from the corner fittings of the container.
Apparently similar scenarios subsequently have enabled TT Club to investigate the causation more directly in both 2013 and 2019. In all instances, the corner fitting apertures have been deformed at both ends of 20ft containers. Analyses have concluded that the probable proximate cause of the incidents related to prior unreported damage. The observed deformation evidences prior damage at both ends of the units.
Twin twenty happens
Many container terminals will be familiar with the issue of inadvertently attempting to lift two 20ft containers from a ship's hold - or indeed in a depot from a yard trailer - whilst the spreader is in 40ft mode. In such circumstances, only the corner castings at the outside ends of the two containers are engaged by the spreader, placing stress on those corner-casting apertures. Following such reported incidents, TT Club has continued to provide alerts about the issue and advice to operators concerning additional procedures or technology to assist in prevention.
Lifting two 20ft containers, even when empty, without the inboard twistlocks engaged can cause serious damage to the outboard corner casting apertures. When lifted from a cell aboard a containership, the cell guides will hold the two 20ft containers roughly in line. It will only be when the containers are lifted clear of the cell guides that the deficient lift will become apparent. The two containers may break loose fully and fall back into the hold, damaging the subject containers, other containers, cargo and perhaps piercing the tank top with the resultant clean-up and potential environmental impact.
Even where the crane operator is alerted to the problem and halts the lift or the containers remain attached, operations will be severely disrupted whilst personnel are lowered into the hold to fit chains to at least the inner corner castings of the containers so that they can be lifted or lowered safely. Such operations are typically complex, requiring great ingenuity, resulting in delays and the potential for considerable damage and even injury.
Lifts in such circumstances may result in the top aperture of the container corner fitting at the attached end of the unit being damaged, resulting in a cruciform "+" shape opening. Unless the damage to the corner casting aperture(s) is identified and repaired, the units concerned are susceptible to a subsequent more catastrophic incident.
"Unless the damage to the corner casting aperture(s) is identified and repaired, the units concerned are susceptible to a subsequent more catastrophic incident."
It may be there is sufficient 'purchase' of the deformed fittings for lifts to continue. Where all appears successful, the unit may continue in service and the incident go unreported. Lack of reporting endangers people and operations subsequently. Perhaps more concerning is the potential lack of vigilance in depot or statutory inspections.
The regulatory maintenance inspection requirements under the International Convention for Safe Containers (CSC), should serve to identify such damage, resulting in the damaged unit being taken out of service for repair.
CSC requires that CTU Operators maintain containers in a safe condition by implementing one of two maintenance schemes, the original periodic examination scheme or the more recent continuous examination programme.
A periodic examination scheme requires a detailed visual inspection for defects or other safety-related deficiencies or damage that could render the container unsafe. This should include an examination of all structurally significant components of the container particularly the corner castings, and be undertaken at least every 30 months.
An approved continuous examination programme subjects containers to examinations and inspections during the course of normal operation. A thorough examination is required in connection with a major repair, refurbishment or on-hire/off-hire or depot interchange. The routine operational inspection may be carried out at any time and should detect any damage or deterioration that might necessitate corrective action. A qualifying routine operational inspection could be completed by a driver when collecting a container.
Of course, the top corner castings of a container will always be at least eight feet from the ground which can make thorough inspection challenging. Thus, while landed on the ground, it may be possible to use a mobile device and selfie-stick, on wheels the driver may only be able to inspect visually through the side apertures of the castings - which also requires good light conditions.
Reporting near misses, actual incidents and serious structural deficiencies should be the top priority for the entire container industry. While primary legal responsibility falls on the CTU Operator, all stakeholders need to step up the plate, particularly those handling the units, and those carrying out inspection and repair services.
"No container that has a serious structural deficiency, especially any damage to the top corner fittings, should be in service."
Today's ease of obtaining and transmitting quality images reduce uncertainties; emerging technologies may even provide continuous certainty. Regardless, no container that has a serious structural deficiency, especially any damage to the top corner fittings, should be in service.
We gratefully acknowledge the assistance in the preparation of this article of Bill Brassington of ETS Consulting.
We hope that you have found the above interesting. If you would like further information, or have any comments, please email us, or take this opportunity to forward to any colleagues who you may feel would be interested.
We look forward to hearing from you.
Risk Management Director, TT Club