The International Heavy Haul Association has developed a common strategy for the future of heavy tonnage railroading that is designed to leverage evolving digital technologies. Heavy haul railroading has historically concentrated on the mantra of longer, heavier trains cycling faster within the limitations of breakpoint railroading. The 4th industrial revolution, which has accelerated bringing on networks of sensors, high broadband communications and artificial machine intelligence, offers a unique opportunity to engineer major efficiencies and safety processes into railway operations. The presentation will share how heavy haul railways are embracing new technologies and how they envision the digital railway of the future, version 4.0. Key technologies, such as communications-based train control, autonomous train operations and predictive maintenance from sensor-based inspections will be highlighted. The presentation will also introduce some of the challenges and pitfalls that railways on the leading edge have encountered and overcome along the pathway to Heavy Haul Rail 4.0.