Tech Wisdom: Automate Twistlock Systems



Current container terminal practice is to manually remove twistlocks from containers – a time consuming activity. This process may one day be automated to benefit both container terminals and liners, a study has shown.

The study was undertaken by Dr Mi-Rong (Kimberly ) Wu, Project Manager at leading Dutch port simulation consultancy TBA.
Automatic twistlock handling stations are mainly machines which operate electrohydraulically and are capable of automatic removal and mounting of twistlocks on containers, Wu explains.
Efforts to develop fully automatic twistlock handling operations are based not only on safety concerns, but on the interest to increase the productivity of container terminals and by extension, shipping lines.
The twistlock handling process at most of the container terminals at present is a manual process which takes around 15-20 seconds per container on average.
However, not every container on a containership is equipped with twistlocks; the percentage of containers with twistlocks depends on vessel type, the layout of the bay, the types of port called at and the TEU factor.
Around 75% of the containers require twistlocks, on the basis of  bay plans for five random vessels that Dr Wu examined. 
TBA carried out simulation experiments to quantify the impact of an automatic twistlock system in a container terminal, in the case that 100% of contianer required twistlocks.
"In this study the assumption was made that all the vessels that are less than 2 hours too late for their window will be considered on time. The punctuality depends highly on the total round trip time. With 9 vessels a high gain of 8% extra of the vessels that are on time can be achieved with the use of an automatic twistlock handling system; with more vessels deployed the gain is marginally. Because of the increased quay crane productivity and the reduced berthing time with the automatic twistlock handling system, the berth productivity for the vessels increases as well. The gain is the largest for the SC terminals because of a higher increase in QC productivity. The increased vessel berth productivity also results in a shorter vessel time in port, which allows for steaming slower at sea and thus saving bunkering costs. "
The paper concludes that when this process is automated, there is not only time saved but also the risk for the dock workers is reduced, and more efficient operations are achieved.

Read the entire paper on PTI's website: Automatic Twistlock Systems


Comments