Ascending stair evacuation experiment
Last week, my colleagues within the Swedish research project Utrymning i långa trappor uppåt: Utmattning, gånghastighet och beteende (English: Evacuation in Long Ascending Stairs: Exhaustion, Walking Speed and Behavior) and I performed the first in a series of three evacuation experiments to be carried out this year. The purpose was to study how individuals, as well as groups, perform during ascending stair evacuation for longer distances, a situation which may arise during evacuations of underground transportation systems and from larger passenger ships.
The experiment went very well, and summing up I can conclude that approximately 70 participants took part. About fifty of these participants took part in an individual experiment, in which we measured not only the walking speed per floor level, but also the physical exhaustion by recording the oxygen consumption and monitoring the participant’s heart beat/pulse. In addition, the participants made subjective estimations of their perceived exhaustion according to the standardized Borg/RPE scale. The other ~20 participants took part in a group experiment, in which all were introduced into the stair at the same time and then asked to evacuate from the bottom to the top of the building. In this part, only the heart rate/pulse was recorded in addition to the walking speed.
Finding a tall enough building to perform the experiment in was not easy, but we finally ended up in the newly built Ideon Gateway in Lund. At most, the participants walked 12 floors before finishing. Most of them managed to do so, but it was clear that they were very much physically affected while doing so. Some participants were forced to stop and take a break during the experiment, but all made it to the top. It will, for many reasons, be very interesting to see the outcome of the analysis. Did, for example, the individual walking speed decrease as the participants got higher and higher up? And how did it decrease? Did it stop to decrease after a while, i.e., reaching a lower value to be kept constant? Is there a clear relationship to the physical exhaustion (both objectively and subjectively/perceived)? And, maybe most importantly, how should this affect the fire safety design concept of deep underground facilities in which ascending stair evacuation is a part of the overall safety concept of that facility?
Later this year an additional two experiments will be carried out. The first in Kista Science Tower in Stockholm, in which participants will have to walk almost three times as long as the ones that took part in Lund – 30 floors, and the second in a long, still standing, escalator in the Stockholm Metro. Preliminary findings may be presented later this year, but the main report including all experiments are not due until the middle of next year. I’ll try my best to keep you posted here, of course! You can find more information about the project by following this link, or by reading this previous blog post that I wrote a while ago.
Finally, I would like to acknowledge the funders of this research project, who have believed in our idea and supported us financially in order for it to be carried out. Thank you Brandforsk (The Swedish Fire Research Board) and Trafikverket (The Swedish Transport Administration).