THE FORMATION OF THE CONTAINER VESSEL LOADING PLAN

10.33815/2313-4763.2020.1.22.064-073

Abstract

Placing containers while loading the vessel taking into account the ports of unloading sequence for providing the access to necessary parties are considered in this article. Also it is viewed within the circumstances of intermediate states of loading the vessel in transition between ports, which must respond to the nautical safety, and arising inertia forces should be within acceptable limits.

Therefore the method of forming the container carrier loading plan is offered, foreseeing placing containers in the cargo holds, which executes requirements to the landing, stability and overall longitudinal strength of the vessel.

The calculation of static moment’s increment on vessel’s axes, which arise in a result of receiving parties of containers while loading the vessel, is presented. One of the requirements is saving trim on the level from 0 to -2,0m. The trim should stay in these limits while loading the vessel due to suitable longitudinal strength. Therefore procedures for determining the limited moments’ values while loading the vessel, which should provide trim for the above-mentioned limits from 0 to -2,0m, are proposed. Analytical expressions, which are used to determine the weight distribution of loading lots providing the required trim of the vessel and its overall longitudinal strength, are also obtained. To do this, formulas were obtained for calculating the average weight of the containers parties located in each cargo hold selected for loading, and also proposed expressions for determining the weight of cargo in each cargo hold depending on its location along the length and height of the vessel.

The procedure of joint placement consideration of how different container load parties can influence on the parameters of landing, stability and overall longitudinal strength of the vessel is presented. To do this, the component of the required static moment depending on the parties’ share weight of the whole weight of the vessel is determined.

To confirm the correctness of the proposed method, the load plan of the ship «Sky Gemini» was calculated with the help of a computer program. «Sky Gemini» can accept containers in eight holds and on their hatches. The vessel is characterized by a maximum average draught of 13,0 m and a maximum displacement of 68318 tons. The loading plan of the above-mentioned vessel was formed with the help of the developed program by three container parties. The first one is 1900 containers weighing 28800 tons is loaded in 10 cargo holds; the second one consists of 600 containers weighing 9000 tons, located in four holds, and the third one weighing 7200 tons and consists of 552 containers is located in three holds. The considered loading satisfies requirements of seaworthiness.