Evacuation performance on offshore platforms under different visibility conditions

The study of evacuation from offshore platforms under restricted visibility conditions has received little attention in previous studies. Therefore, evacuation performance on offshore platforms considering different visibility conditions is investigated in the study using agent-based techniques. First, the evacuation speed model is modified and validated based on the experimental data. Then, cases are designed considering different visibility conditions, and the simulation results are analyzed and discussed in terms of evacuation time, evacuation flow rate and queuing time. The results show that the visibility distance has a significant impact on the evacuation process. Based on the difference in evacuation flow rate, the evacuation process is split into two phases. Statistical methods are used to determine the relationship between the flow rate and visibility distance for both phases. Phenomena like “long tail effect” and queuing are observed that can affect the evacuation efficiency. The reasons behind the phenomena are then explored. Finally, the effect of smoke visibility on the evacuation process is studied. It is found that the smoke visibility in a fire accident can negatively affect the evacuation efficiency, with the workers on the lower and working decks being most adversely affected. As a result, the flow rates in both phases are reduced. Additionally, investigations have been conducted on how the pre-evacuation time affects the evacuation efficiency in Case C. It demonstrates that the longer the pre-evacuation time, the lower the flow rate becomes, indicating that the greater the impact of smoke visibility on evacuation efficiency. This study may be useful for predicting the evacuation process on offshore platforms under restricted visibility conditions, and it may also provide suggestions for the formation of evacuation strategies.