Identification of problems occurring while loading containers

Abstract

This thesis introduced the reader into container operations starting from the constructional basics of container vessels and containers. Leading into containers by explaining the markings, several types of containers, loading plan, lashing procedures and the cargo program used on board. All of these were important as we continued further into problems of loading containers as the discovered problems were related to these subjects. The vessels loading plan as bay view is used to monitor the cargo operations. Every container and its location and empty positions can be confirmed by numerated codes by the crew. Depending on the user the desired information can be included such as container weight in tons or IMDG containers. The loose lashing equipment onboard consists of several types of twistlocks, single stackers, compensation pieces, bottom stackers and twist stackers which are stored inside storage bins. These together with turnbuckles and lashing rods are holding the containers in positions which are attached to ships fixed lashing equipment such as lashing plates hold the containers in place. Containers are secured to limit the external forces affecting them to keep them in place during voyages. These external forces consist of storage, handling, and transport stresses. These forces are created by the vessel’s movement in all six directions and external forces such as slamming waves or containers hitting each other. To limit these forces, containers are secured on deck by twistlocks, turnbuckles and lashing rods with cross lashing or any other means according to vessels CSM. Inside cargo hold there are bottom stackers with stacking cones. Automatic twistlocks or stacking cones are put between containers and insertion guides together with stack weight hold the rows horizontally in place. The Loadstar cargo computer could not recognize and place the unstandardized containers correctly when importing the received baplie into ships computer. To fix this the user must go through every single container one by one to display everything correctly. In most cases often one of the above-mentioned solutions fixes the problem but every single step must be gone through to make sure all possible reasons for denial of container is excluded. The real-life examples showed that the problems exist because of the constructional characteristics of containers in types of length 43ft, height 9ft6 ½in high cubes, 45ft reefer containers and flatracks. Problems were encountered in normal operations on daily basis during stowing and securing. The problems in lashings limited the possibilities of stowing in the cases of reefers and high cubes. In the case of flatracks the problems were related to both securing and stowing. Unnoticed inadequate lashings created a danger to cargo stowed on it and for the vessel. In stowing the characteristics of flatrack allow only one type of stowing which is on uppermost tiers without anything stowed on top. These types of unstandardized containers need to be stowed and secured in specific way. With the solution we came up with, larger vessels can take unstandardized containers to maximize cargo capacity. The base of the modified platform is the collapsed 40ft flatrack with corner castings added to fit 10ft, 20ft and 35ft, and not only to fit a normal 40ft container. The platform is acting as a middle piece between a 40ft container below and any size of container stowed on top. This solution helps to load different but more common unstandardized containers without the need of long pre-loading stage.