Transient 3-D numerical simulations were performed to analyze the fire safety in a long railroad tunnel equipped with the mechanical ventilation system using dampers and jet fans. The flow behaviors of heat and pollutants were investigated for various emergency operation modes of the ventilation system in a rescue station and escape route in the long railroad tunnel in case of fire. The results showed that the ventilation mode, which extracts heat and pollutants from the tunnel on fire and pressurizes the opposite tunnel, was very effective for the fire safety of the rescue station. To evaluate the ventilation efficiency of the escape route, various geometries such as connection and slope angles of the escape route were considered. The importance of the jet fan operation in the escape tunnel on the ventilation performance was also discussed in detail.