More than just weighing

The IMO recently approved the amendment to SOLAS to mandate the provision of the verified gross mass in order to load containers on board a ship. This is expected to be implemented globally in July 2016.

This decision has increased the focus on how terminals will weigh containers if the weight has not already been verified prior to reaching the terminal. Some terminals already have weighbridges and see this as the solution. However, many are concerned about the potential operational disruption, such as the impact on truck turnaround times.

The latest technology of twistlock load sensing is being seen as an alternative to weighbridges. At this stage it appears this may be the only viable alternative, as other weighing systems do not have sufficient accuracy.

The technology can be installed on any spreader and on any type of terminal handling equipment, with the sensors measuring the load on each twistlock. For export containers, the system can be installed on yard cranes, straddle carriers and lift trucks to measure the gross mass as it is unloaded from the truck or train.

Measuring the load on each twistlock is done during the normal load cycle, so no delay occurs, and the actual weight can then be sent to the TOS to enable accurate weights to be used in the ship loading plan. This achieves the objective of the SOLAS amendment.

This technology has been around for a few years now and is proven. Many in the industry consider it the best solution, but, as always, cost is a deterrent. The cost per spreader is about €15,000 for a single lift and €20,000 for a twin lift. Add another €5,000 for effective integration and communication with wider operating systems and the cost appears high.

There is, of course, potential for terminals to charge for offering a container weighing service, whether to their primary shipping line customers or to the ‘shipper’ entities who are obliged to provide the verified gross mass. Where this is the case, it is probable that a return on investment could be achieved fairly rapidly.

Look deeper

However, there are other safety benefits to twistlock load sensing that make the system a very sound investment. It can detect and prevent a number of all-too-common accident situations, including:

• Lifting of trailers or rail wagons still connected to the container
• Lifting when not all the twistlocks are engaged with the container
• ‘Snag loads’ where the container is still locked with the stack or stuck in the cell guides.

Moreover, the measurement of each corner of a container means that load eccentricity (in both single and twin lifts) is also captured. This can allow side shift of the spreader to prevent the container becoming stuck in the cell guides. It also allows truck drivers to know the eccentricity of the container to help prevent overturning.

From an operational management perspective, the measurement of twistlock load cycles also enables optimisation of maintenance activities. In a general sense twistlocks can then be replaced when required and not just at preordained intervals. Further, the system can be expected to monitor condition and detect overload situations, leading to inspection and replacement, if needed, before they fail.

As a major insurer in this industry, the TT Club sees many accidents resulting in damage to equipment or cargo and, tragically, personal injuries. Many of these accidents can be prevented by the use of twistlock load sensing technology. Not only yard equipment and export containers, but also quay cranes benefit from all the safety features of this technology. Just knowing the eccentricity of an import container could prevent accidents, often outside the port area. If we can prevent such tragedies as a family being crushed in their car by an overturning truck, the investment will be worthwhile.

Twistlock load sensing offers more than just weighing. The safety benefits alone should justify its implementation, but the wider operational benefits are also compelling. The TT Club would recommend that operators evaluate these with a view to installing the technology on every spreader. It can be anticipated that one day this technology will be – as seat belts in cars – standard.

Laurence Jones is risk assessment director at the TT Club.