California State Rail Plan 2007-08 to 2017-18

Chapter XVI – Major Freight Issuesmovement system, accommodate international trade and also benefit the rest of theNation.THE CHANGING NATURE OF RAIL FREIGHT MOVEMENTS/COMMODITIESRail provides three basic types of freight service: bulk unit train, mixed carload,and intermodal (container, trailer, and automobile). These services differ in theirmarkets, operations, and contributions to California and the nation’s freighttransportation system.Bulk Unit TrainsBulk unit trains move very high volumes of a single commodity such as coal,grain, minerals, and waste. In California, all of these commodities with theexception of coal are move. (Intermodal containers and specialized automobilecarrier cars are frequently made up into unit trains; these are addressed in thediscussion of intermodal service.) Commodity flows tend to be one-way; cars(usually hopper cars) move loaded from shipper to receiver and are returned emptyfrom the receiver to the shipper. Commodity flows tend to be “door-to-door,”moving from shipper to receiver entirely by rail. Bulk unit train commodities arehighly sensitive to transportation cost because they are heavy but, like coal andgrain, relatively low in value. Unit trains provide the efficiencies needed to movethese commodities cost-effectively. This is accomplished through:• Long trains (up to one and one-half miles) of rail cars moving alongmainline corridors, which allows economies of scale in operation (lesshandling cost, more efficient utilization of locomotives, greater fuelefficiency, etc.);• Uniform composition (usually a single commodity and railcar type), whichsimplifies the collection and distribution of railcars along feeder lines; and• Customers who tend to produce or consume large quantities of thesematerials, reducing the number of origins and destinations that need to beserved.• Unit train flows tend to occur along well-defined, high-density corridors,rather than clustering at major urban rail hubs.219