One Train per Ventilation Zone: Application and Innovation
In recognition of paragraph 7.2.5 of the National Fire Protection Association (NFPA) Standard 130 for Fixed Guideway and Passenger Rail Systems, a major commuter railroad project design team has undertaken detailed coordination of its train signaling, traction power and tunnel ventilation systems. Per the writing of the Standard, the coordination effort was aimed at designing the systems to match the total number of trains that could be between ventilation shafts during an emergency, but also recognized that, the best protection to passengers is to allow no more than one train in a ventilation zone. The coordination of the train signaling, traction power and tunnel ventilation system designs per NFPA 130 paragraphs 7.2.5 and A.7.2.5 has permitted the project to achieve a reasonable degree of safety from fire and its related hazards, while at the same time: preserving the commuter railroad’s throughput requirements; reducing overall construction costs; and, minimizing civic/environmental impacts. In particular, the design coordination has permitted the project to forego tunnel fan installations within existing structures in one portion of the project, and an innovative fan plant design between two tunnels has precluded the need for an additional tunnel ventilation shaft in another portion of the project.