Ken Cheng, Steve Cress and Don Minini have published on DC arc flash as it relates to rail systems.
This ground breaking paper addresses some issues with the DC calculation models we have today and introduces assistance from Kinectrics in difficult DC applications. Kinectrics contracts arc flash calculations jobs in the US through e-Hazard.com or their US office.
The abstract is below should you be a member of APTA and or want the conference proceedings.
During accidental faults on electrical power systems, workers may be exposed to hazards from electrical arcs. A prime concern is the exposure of workers to the intense radiated component of the arc energy, which has the potential to cause skin burns. In the United States of America, it has been reported that approximately 80% of electrical injuries are due to burns from exposure to radiant and convective energy from electrical arcs. Arc hazard analysis is a safety assessment, dedicated to protecting workers who might be exposed to radiated thermal energy from electric arcs. In this paper, the focus is on incident energy released from direct current (DC) arcs, which should be of particular interest to the transit industry.