Fruehauf 40' Exterior-Post Volume Van Trailer Assembled Erie-Lackawanna #1Details: A transport revolution started in the 1950s the advent of the piggyback trailer. No longer was it necessary to transfer loads to and from freight cars to local trucks for shipment or delivery. Instead, the entire loaded trailer could be driven from a loading dock to a freight yard, loaded on a train, then delivered to its final destination. The Pennsylvania Railroads TrucTrain was a pioneer in this area, but many other railroads offered their