ESTIMATED TIME OF THE EVACUATION OF PEOPLE IN HIGHLY HAZARDOUS AREAS
This paper described personnel safety assessment during the evacuation of operational buildings. The standard evacuation time estimate method is applicable only in cases when personnel are on escape routes at the beginning of the evacuation, and they are ready to start moving towards a fire exit. In a real fire situation the escape paths can start from workplaces located in the distance from the escape routes due to organizational, technologic, structural and other aspects of an operational building. The workplaces located in a high-density working area on upper levels can be given as an example. However it is suggested that the problem should be solved by means of the chronometric method of the time estimate for the evacuation movement of personnel on work sites, since there are no appropriate calculation methods that would consider a variety of escape routes. In this case not only permanent workplaces but temporary ones as well, which can be used for equipment repair, premises or building renovation, should be considered. To explain his point of view the author gave an example of the announced evacuation of personnel at a gas compressor station operated by the pipeline company, in the course of which the time that personnel needed to climb up a ladder in the air-intake shaft of a gas turbine, or go down the fire alarm maintenance floor, or move inside a gas-pumping unit was tracked. The statistics are available from the experiment. It is suggested that the experimental data should be used later on for assessing safety of the escape routes of personnel moving from the above mentioned workplaces to the fire exit by means of the safety index. The index estimation method is based on randomness in the change of the evacuation time as well as the time when the escape routes may be blocked during a fire, and the probability that personnel stay at a gas compressor station. In addition the method of the evacuation start time estimate is outlined, which includes such aspects as simple and complex sensorimotor reactions, decision time, the time needed for taking operative actions and switching off the equipment, the time for the creation of a potential fire hazard, the delayed action and reliability of the fire alarm system and evacuation management system. Instructions on how to use the index estimation method for fire prevention at the gas compressor station are given.