AGW for efficient freight transport in container yard. Supply models and costs

Different modes of transport are frequently used to transfer goods from origin to destination, especially on medium-long distances, in relation to the network supply, the available services, the costs. The transfer from one carrier to another, in an interchange node such as a port, a rail station, a logistics terminal, often implicates an increase of monetary and temporal costs, connected to material and immaterial operations. The principal aim is to minimize the overall cost of transport, but the freight interchange node can represent critical steps in logistics chain and for this reason much attention is now committed to actions to make efficient the functional organization of the terminal. In the last years an increasing interest is directed to the use of vehicles technologically advanced with automation of functions. The paper focuses on a particular technology, conceived recently, otherwise an intelligent rail wagon called AGW (Automated Guided Wagon) for handling of containers in a port. The use of intelligent system AGW as handling unit of containers in the yard, would allow the overcoming of diseconomies of scale and the reduction of the handling times and costs through a flexible management in relation to the characteristics of the transport supply and demand, the latter subject to a high variability. In the paper, after a brief description of the AGW technology and the advantages connected to the use of this handling system in a freight interchange node, the attention is focused on a comparative analysis between the handling system now operating in the container port (RTG, Straddle Carrier, AVG, etc.) and the system that involves the use of AGW. This analysis is made on the operational characteristics of the different handling systems, through the use of: functional schemes, with the aim to carry out evaluations related to the spatial, organizational and relational structure of container yard equipped with different handling unit; network models (graphical representation of links and paths; basic cost parameters) for the schematization and simulation of container handling in the yard; cost models for quantitative evaluation of monetary and temporal impacts, that derive from the use of different handling unit in the yard.