Optimal loading of double-stack container trains

We develop a new mathematical model for optimizing the loading of double-stack container trains. We analyze the practical importance of multiple objectives reported in the literature and formulate two new objectives: maximizing profit and minimizing tardiness. The model accounts for containers of different types, weights, and heights, and their feasible loading combinations on a wagon satisfying real operational constraints. The model is solved optimally by CPLEX after exploiting the problem specific properties. A decision support system based on this optimization model has been deployed by a major train operator in India. Numerical cases show that our model can reduce the container haulage cost by about 3%.