- Author
-
Galea, E. R.
|
Blake, S. J.
|
Dixon, A. J. P.
|
Gwynne, S.
- Title
- Report on Analysis Conducted by FSEG of Video Footage Derived From the VERRES Evacuation Tests Conducted at Cranfield on the 25 January and 1 February 2003.
- Coporate
- University of Greenwich, London, England
- Report
-
Paper No. 03/IM/110,
December 2003,
44 p.
- Keywords
-
evacuation
|
stairways
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stairwells
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exit signs
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human behavior
|
flow rate
|
tests
|
accidents
|
survivability
|
aircraft accidents
|
simulators
|
human performance
- Identifiers
- planned test matrix for trials; planned and actual experimental goals; summary of data that could be extracted by UoG from the video footage; summary description of participant and CC behavior during trials; stair population densities; hypothetical densities based on imposed packing densities; average stair flow rates for all trials; flow rates expressed per unit of effective width; passenger exit delay time distributions; participant average exit flow rates
- Abstract
- This report concerns the analysis undertaken by the University of Greenwich (UoG) on the evacuation data collected as part of the EU funded VERRES project (GMA2/2000/32039). This data primarily concerns the passenger use of the stairs and passenger exit hesitation time analysis for the upper deck slide. Unfortunately, the trials did not proceed in the controlled manner that was originally planned and so the analysis did not yield the detailed information that was originally hoped. The main difficulties associated with these trials were: 1) CC did not behave as originally intended. This meant that it was not possible to (a) measure the propensity of passengers to freely elect to use the staircase and (b) it was not possible to estimate impact of crew influence on passenger stair efficiency and flow rates. It was apparent that in all the trials, crew played some role in managing the passenger flow on the stairs. 2) The camera angle for cameras intended to show the passenger stair behaviour on the first day trials were such that three separate cameras would need to be used to investigate passenger performance and behaviour on the stairs. Furthermore, even using these three cameras, a central portion of the stair was missing from view. While this difficulty was corrected for the second day's trials, this meant that much of the video footage collected on the first day was either extremely difficult to analyse or not appropriate for analysis. 3) While the upper deck slide is considerably different to that expected to be used in actual VLTA such as the A380, the passenger exit hesitation times are of interest in aiding our understanding of passenger behavior. As these were the first trials to make use of the upper deck slides, the Cranfield crew that staffed the exit exhibited great caution and as such the majority of crew behaviour at the upper deck exits can be described as extremely non-assertive. This crew behaviour significantly biases the behaviour and hence performance of the passengers. It is thus not clear if the resultant passenger behaviour is a result of the sill height and slide length or the lack of assertiveness of the crew. However, it is clear from these trials that crew can exert an influence on the performance of passenger stair usage. Passenger behaviour in utilising the staircase is both rich and complex and warrants further investigation. These trials support the view that for crew to consistently make appropriate or optimal redirection command decisions that include the possibility of using the stairs as part of the evacuation route, they must have sufficient situational awareness. Equally, passengers can only make appropriate or optimal redirection decisions if they too have sufficient situational awareness. This situational awareness may need to extend between decks. Passengers were also noted to make heavy use of the central handrail while both descending and ascending the stairs. The presence of the central HR effectively created two staircases. By effectively separating the crowding on the stairs, reducing passenger-passenger conflicts and providing an additional means of passenger stability, it is postulated that the stair flow rates may be positively influence through the presence of the central HR. Flow rates in the UPWARDS direction was found to be greater than flow rates in the DOWNWARDS direction. This was thought to be due to the packing densities on the stairs which is a function of the motivation of the passengers, the travel speeds of the passengers and the feed and discharge characteristics of the staircase and surrounding geometry. It was also noted that the average unit flow rate in the DOWNWARDS direction was equivalent to that specified in the UK Building Regulations. Clearly, most of the parameters can be influenced by both crew procedures and cabin layout. Concerning the passenger exit hesitation times for the higher sill height, the trials produced inconclusive results. While the exit flow rates are lower and the passenger exit delay times are longer than would be expected for a normal Type-A exit, it is clear that the extreme unassertiveness of the cabin crew positioned at the exits and the lack of motivation of the passengers exerted a strong influence on the data produced. The reaction of the passengers in these trials was to be expected as the trials were not performed under competitive conditions and the reaction of the cabin crew could also be understood as safety concerns were paramount given that these were the first trials of their type to be conducted at Cranfield. Finally, due to the small number of data points provided by these trials, there is insufficient data up on which to claim statistical significance for any of the observations. Clearly, much more work is required in order to generate essential data to improve our understanding of passenger performance, passenger-crew interaction and passenger-structure interaction within VLTA configurations.