Simulation Modelling of Vitória-Minas Closed-Loop Rail Network

Abstract

Summary. This paper presents a closed loop simulation model that represents the mining logistics chain of the Vitória Minas Railway (VMR), Brazil. The simulator includes the loading process, circulation of loaded trains, unloading of ores for external and internal markets and the distribution of empty trains for new loads. General cargo and passengers trains are also included in the model, which, along with the queues formed in the circulation and the preventive and corrective maintenance of rolling stock, tracks and equipment, interfere with the transportation of iron ore. The primary objective of the iron ore transport is to meet the daily loading and unloading schedules and minimize queues by maximizing the operations at the loading and unloading points. The VMR simulator developed uses macro-mesoscopic approach with Monte Carlo simulation. To validate the simulator, we used actual data of the railway and compared with reality. We obtained a very good adhesion to the value of 2.9% for the validation scenario (Scenario 1) and 3.4% for the scenario with reducing the number of lots of wagons (Scenario 2). We concluded with this simulation that it is possible to reduce the number of GDE wagons without reducing the current level of productivity of the rail system. MODELAGEM DE SIMULAÇÃO DO CIRCUITO FECHADO DA FERROVIA VITÓRIA À MINASResumo. Este artigo apresenta o modelo de simulação do circuito fechado da rede logística de minério de ferro da ferrovia Vitória Á Minas (VMR), Brasil. O simulador inclui o processo de carregamento, circulação dos trens carregados, descarregamento para os mercados externos e internos e a distribuição dos trens vazios para novos carregamentos. Os trens de carga geral e de passageiros também foram incluídos no modelo, bem como suas filas de formação e as manutenções preventivas e corretivas do material rodante, que interferem no transporte do minério de ferro. O principal objetivo do transporte de minério de ferro é atender as programações de carregamento e descarregamento e minimizar as filas maximizando as operações nos pontos de carregamento e descarregamento. O simulador VMR desenvolvido utiliza uma abordagem macro-mesoscópica de simulação de Monte Carlo. Para validar o simulador, foi utilizado dados da ferrovia e comparado com a realidade. Obtivemos uma aderência muito de 2,9% para o cenário de validação (cenário 1) e 3,4% para o cenário com a redução do número de lotes de vagão (cenário 2). Concluímos que com esta simulação é possível reduz o número de lotes de vagões GDE sem reduzir a produtividade da ferrovia.

Improving Strategic Decision-Making in a Closed-Loop Rail Network with Hybrid Simulation-Optimization Modeling

“…This fact is particularly critical in railways running on a closed-loop framework composed by unit trains (carrying the same commodity). In such systems trains are formed once in the network with a fixed number of railcars and run through the following closed circuit without being split or stored in the route: (i) loading; (ii) moving loaded to a rail port terminal; (iii) unloading; and (iv) moving empty to a loading terminal (Franzese, Fioroni and Botter, 2003;De Faria and Cruz, 2015). Closed-loop systems are modeled as opposed to the ordinary dispatching model, where trains are formed and disposed in the edges of the network with the purpose of analyzing line utilization and total delay.…”