Scheduling Freight Trains in Rail‐Rail Transshipment Yards

Transshipment yards, where gantry cranes enable the efficient transfer of containers between freight trains, are important entities in modern railway systems. They facilitate a general shift from point‐to‐point transport to hub‐and‐spoke railway systems, a shift being driven by concerted efforts within the European Union (EU) to transfer goods traffic from road to rail. Modern rail‐rail transshipment yards accelerate container handling so that multiple smaller trains, with identical destinations, can be consolidated onto a reduced number of trains. An important problem attendant upon the daily operations of a transshipment yard is the train‐scheduling problem, which involves determining the processing order of trains at parallel railway tracks. The present paper investigates this problem, with a special focus on resolving deadlocks and avoiding multiple crane picks per container move. A mathematical program along with a complexity proof is provided, and two different procedures are described: exact (dynamic programming) and heuristic (beam search).