Evolution History of China's Railway Heavy-haul TransportationDeveloping phasesPrimary technologies and equipmentsMain results brought about by heavy-hauling technologyRole and Significance of Heavy-haul Transportation on Datong-Qinhuangdao RailwayTechnical and Economic Analysis of Enhancing Freight Capacity of Datong-QinhuangdaRailwayCoal outward transport volume from the Three-West regionsSituation analysis of coal transportation on Datong-Qinhuangdao RailwayAnalysis of methods adopted for increasing coal transport volumeKey Technology Comparison on Operating 20,000-ton Heavy-haul Joined TrainsLoeotrol technologyECP braking technologyDemonstration for Datong-Qinhuangdao Railway to adopt Loeotrol technologyAnalysis of the Three Key Technical Issues for Operating 20,000-ton Heavy-haul Joinetrains by Adopting Locotrol DeviceCommunication reliabilityPeriodical circulation brakingTrain longitudinal impulseHeavy-haul Transport Technology SystemLocomotive TechnologySystem integration technology of SS4 DC-drive electric locomotiveHXD1 locomotiveHXD2 locomotiveHeavy-haul Vehicle TechnologyVehiclesKey technology and equipmentTechnical Platform of Communication and TransmissionData communication for network-based wireless locomotive synchronous���� Adjusting distribution of minor stations on D~tong-QinhuangdaoRailwayAdjusting distribution of locomotive depots and vehicle depots onDatong-Qinhuangdao RailwayAdjusting distribution of comprehensive maintenance servicesTechnical EvaluationSystem integration innovationTechnology and equipment innovationTransport organization innovationTechnical system innovationEconomic Evaluation