Modeling an offshore container terminal: the Venice case study

In order to reduce marine transportation times and related costs, as well as the environmental impacts, an alternative multimodal route to the current Suez-Gibraltar-North Sea corridor for the containers shipped from Far and Middle East was identified as potentially very effective. A key operational problem to achieve this result is the capacity and the effectiveness of the terminals within the concerned new logistic chain. In this framework, the Venice Port Authority is developing a project aimed to improve relevantly the potential of its container terminals to al-low loading/unloading of containers to and from the Central Europe. The project includes a new offshore terminal for mooring huge ships (up to 18.000 TEU) in the Adriatic Sea and a link operated by barges with an onshore terminal in Venice to overcome the constraints for the navigation of the containers ships in the Venetian lagoon. This innovative operational scheme requires a deep functional analysis to ensure the full capacity operation, assess the reachable performances and correspondingly dimensioning the required equipment (cranes, barges, quays, etc.). For this purpose, the authors developed a specific discrete-events simulation model. The paper includes the presentation of the model and the results of its application to Venice case study, by identifying the benefits achievable with this approach and the potential wider application fields

Intermodal terminals simulation for operation management

A freight terminal is a key node in a transportation network and the transit time of containers through this terminal represents one of the most relevant bottleneck in logistic chains. The system performance reduction and the corresponding increase of transit time is often due to the increase of the freight flow without a corresponding increase of stacking and handling capacity. For this purpose it was decided to approach the problem by a discrete event simulation model, in order to reproduce the activities carried out inside an intermodal terminal, to calculate the total transit time and to identify the bottlenecks. The transit time of a cargo unit in a terminal is the summation of times required for the development of each phase of the process (waiting time + operational time). Therefore, the first step was the identification of the main activities and the analysis of waiting and operational phases, in order to quantify the times of each phase. For modelling the software Planimate® was used. Planimate® allows the simulation of a process as a set of discrete events, in series or in parallel, through the use of hierarchical networks. In order to optimise handling operations on containers, different scenarios were simulated with various fleets of trailers and front cranes to investigate the corresponding variations of performance indicators. For the application of the model an Italian case study was chosen: the container terminal inside the harbour of Livorno (Darsena Toscana Terminal)

Limits and opportunities of risk analysis application in railway systems

Risk Analysis is a collection of methods widely used in many industrial sectors. In the transport sector it has been particularly used for air transport applications. The reasons for this wide use are well-known: risk analysis allows to approach the safety theme in a stochastic - rather than deterministic - way, it forces to break down the system in sub-components, last but not least it allows a comparison between solutions with different costs, introducing de facto an element of economic feasibility of the project alternatives in the safety field. Apart from the United Kingdom, in Europe the application of this tool in the railway sector is relatively recent. In particular Directive 2004/49/EC (the "railway safety directive") provides for compulsory risk assessment in relation to the activities of railway Infrastructure Managers (IMs) and of Railway Undertakings (RUs). Nevertheless the peculiarity of the railway system - in which human, procedural, environmental and technological components have a continuous interchange and in which human responsibilities and technological functions often overlap - induced the EC to allow wide margins of subjectivity in the interpretation of risk assessment. When enacting Commission Regulation (EC) No 352/2009 which further regulates this subject, a risk assessment is considered positive also if the IM or RU declare to take safety measures widely used in normal practice. The paper shows the results of a structured comparative analysis of the rail sector and other industrial sectors, which illustrate the difficulties, but also the opportunities, of a transfer towards the railway system of the risk analysis methods currently in use for the other systems

A tool for intermodal terminals simulation

Railway freight terminals play a key role within the multimodal transport and the transit time through these terminals represents one of the most relevant criticism in logistic chain. Therefore, a freight terminal it is a basic node in a transportation network, where thousand of daily decisions are taken to manage this sustained flow of containers. Predict the traffic evolution inside and near of terminal, it is important in order to manage the required flows and the available areas. One of the main cause of a system performances reduction is, in fact, the increase of the freight flow, in particular if it has not been available an appropriate increase of stacking capacity and management of the flows handled. Otherwise the consequences are the congestion of terminal flows and relative increase of transit time. In the research, a decision support system for the management of an intermodal container terminal is presented and a simulation tool it has been developed. In the last years the role of simulation becomes of paramount importance in managing and planning of such terminal activities. For this purpose it has been developed simulation models of the activities carried out inside an intermodal terminal. A discrete event simulation tool has been implemented with the aim of calculate the total transit time and to identify the bottle neck, in order to reduce the probability of system performances reduction by optimization of the unloading and handling operations of containers. The simulation has been applied to Darsena Tuscany Terminal in Livorno harbour. This work is the continue of the activities developed by the research team, taking into account the analysis of the functioning and modelling of intermodal terminals

Risk analysis models for level crossing operation.

The study concern different approaches for risk assessment for level crossing. For the identification of level crossing main components SHEL model is used. Two different methodologies have been developed to determine the risk related to a level crossing. The first methodology gives a global evaluation of the risk and for the evaluation of interference using the Fault Tree Analysis; the second is based on formal methods and simulations (e.g. Petri nets) and it is possible to simulate what really happens in correspondence to a level crossing during the train operation

La liberalizzazione del mercato ferroviario passeggeri in Italia e gli effetti sul sistema dei trasporti.

Da molti anni in Italia ed in Europa è atto la tendenza di una continua crescita di domanda di mobilità. Oltre ciò è da evidenziare la costante integrazione economica oltre che infrastrutturale dell‘Unione Europea unitamente ad un‘apertura ed ampliamento verso nuovi Stati Membri. In tale contesto si colloca, pertanto, il processo di liberalizzazione dei mercati e quindi anche del settore dei trasporti. In Italia, poi, si registra il primo caso in Europa relativo all‘attivazione di un servizio ferroviario su linee ad Alta Velocità interamente gestito da un operatore privato con servizio in open access. Scopo di tale lavoro è, quindi, lo studio dello stato dell‘arte e l‘analisi degli effetti della liberalizzazione del mercato ferroviario sul sistema ferroviario italiano

Level crossing safety: the influence of different closure type and parameters

Level crossings represent intersections with high risk and cause serious damages and injuries to many thousand of road users and railway passengers. The paper analyzes various alternative systems for level-crossing protection and problems relating to the systems adopted. The aim of the research is the evaluation of road user’s behaviour approaching a level crossing and the influence of the different typologies and characteristics of level crossing. Different phases of closing barrier are simulated using Petri net model

Modellazione delle fasi funzionali e dell’architettura di un passaggio a livello.

Il comportamento di un sistema comunque complesso può essere ricondotto alla definizione della successione di fasi funzionali che ne caratterizzano l’evoluzione fisica e temporale. Ai fini dell’analisi della sicurezza un sistema ferroviario può essere visto come il risultato di una completa e complessa interazione di dispositivi tecnologici, regole e direttive e comportamenti umani. Oggetto di tale studio è la riproduzione attraverso modelli di simulazione di diverse architetture di passaggi a livello ma soprattutto delle fasi che ne caratterizzano il funzionamento al fine di osservare le modalità con cui il sistema stesso evolve (fisicamente e temporalmente), valutando gli esiti di modifiche effettuate sulla sua architettura, ma soprattutto gli effetti provocati da eventi critici che possono interessare una o più fasi operative

Intermodal terminal simulation for operations management

A freight terminal is a key node in a transportation network and the transit time of containers through this terminal represents one of the most relevant bottleneck in logistic chains. The system performance reduction and the corresponding increase of transit time is often due to the increase of the freight flow without a corresponding increase of stacking and handling capacity. For this purpose it was decided to approach the problem by a discrete event simulation model, in order to reproduce the activities carried out inside an intermodal terminal, to calculate the total transit time and to identify the bottlenecks. The transit time of a cargo unit in a terminal is the summation of times required for the development of each phase of the process (waiting time + operational time). Therefore, the first step was the identification of the main activities and the analysis of waiting and operational phases, in order to quantify the times of each phase. For modelling the software Planimate® was used. Planimate® allows the simulation of a process as a set of discrete events, in series or in parallel, through the use of hierarchical networks. In order to optimise handling operations on containers, different scenarios were simulated with various fleets of trailers and front cranes to investigate the corresponding variations of performance indicators. For the application of the model an Italian case study was chosen: the container terminal inside the harbour of Livorno (Darsena Toscana Terminal)