TT Talk - Stack profiling technology

It is not uncommon during terminal operations - in the yard and on the ship - for the spreader, or the container attached thereto, to collide with stacked containers. Often resulting from operator error, such incidents can be extremely costly and cause serious operational difficulties. This is another hazard which has now been effectively engineered out through the development of stack profiling technology.

"There is a degree of inevitability that an incident will occur"

Given generally strong throughput in container terminals today, space constraints and increasing demands of ship turn-around times, it may be inevitable that handling equipment will collide with containers in a stack, either in the container yard or on the ship itself. This is re-enforced through the TT Club's claims experience, where in excess of 500 incidents costing in the region of US$34 million have occurred over the last nine years.

The risks associated with this hazard are wide ranging - from more minor incidents of physical damage to the box alone to fatalities, as well as containers and cargo being lost overboard from the ship. In addition to container and cargo damage or bodily injuries, consider the potential of business disruption, delaying operations and ship schedules, as well as probable damage to the handling equipment. Other aspects may be less quantifiable, being the potential exposure to reputational damage and managements' investigation and resolution overhead.

These incidents occur both land and water side, wherever handling equipment is being operated to reposition containers. TT Club's claims experience reveals containers knocked off existing stacks on board a berthed ship during loading and discharge operations by quay cranes. Similarly, there have been numerous incidents land side on the quay apron and the yard where RTG's, RMG's and Reach Stackers dislodge containers.

Driven by the existence and to a degree the inevitability associated with the risk, technology has been being developed over several years with a view to engineering out the possibility of a stack collision. It is now possible, with effective selection and installation of what is widely recognised as stack profiling technology, for such incidents to be totally prevented.

Automated yard cranes are installed with sensors and software to record where all containers are in a given container stack. The primary technology is lasers used for distance measurement. The lasers are mounted on the handling equipment and are constantly measuring distance from the machine to the container stack. An accompanying on board computer processes the reported measurements, processes telemetry from the handling equipment, and monitors the movement of the spreader. When a potential danger is recognised, the system works to prevent an accident. The same technology used in automated settings is available to support manual operations.

TT Club collaborates with organisations such as PEMA (Port Equipment Manufacturer's Association) in order to identify technologies that may assist in loss prevention. Thereafter, monitoring implementation, the Club seeks to ensure that such technologies are proven to achieve their objectives. Stack profiling on quay cranes and yard cranes is clearly a proven technology that can deliver both operational efficiencies as well as eliminating collisions, thus saving the associated costs and lives across the industry.

Analysis of claims from current automated container terminals which rely on this type of technology confirms that stack collisions are eliminated. The technology is not restricted to newly commissioned handling equipment and can also be retrospectively installed on manual or remote controlled quay and yard handling equipment.

Most of the large port equipment manufacturers can provide this technology through a growing number of suppliers, as well as other technology companies including but not limited to TMIEC, ABB and Siemens. Inevitably, the price is reducing as the technology improves and becomes more commonplace; it is understood that the current cost is in the region of US$50,000 per crane. While this may appear expensive, the issues around stack collisions are real and the risks and exposures should not be underestimated, nor should the potential for such an incident to occur at any facility. It might be suggested that the return on investment can justify the expenditure when weighed against the potential savings associated with the prevention of just one serious incident, particularly if that incident causes a loss of life or limb.

In summary, if a container terminal has not experienced an incident involving a stack collision, it may already have deployed stack profiling technology or it is perhaps only a matter of time before an incident will occur. TT Club recommends that all new cranes and handling equipment are specified and supplied with this technology and consideration be given to retro-fitting existing equipment.

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.

Peregrine Storrs-Fox

Risk Management Director, TT Club

Staff Author

TT Club