ENGINEERING SCIENCES DIVISION UNSTEADY AIRFLOWS IN RAPID TRANSIT SYSTEMS Part 1: measurements on the London Transport

The measurement of pressure fluctuations on the London Transport Victoria Line is described and results are presented in sufficient detail for accurate comparisons to be made with theoretical models. Measurements were obtained during the night-time shut-down period. and so complicating effects due to other trains are absent. The results give a clear indication of the relative importancc of several events such a s entry to and exit from a station. The effectiveness or cross-passages for draught reliel ’ is clearly demonstrated. A computer program is used to simulate thc airflows, and satisfactory correlation is obtained with the measured results at different train speeds. The program is used to predict system characteristics that werc not measured during the tests. It is found that platform wind velocities and passenger pressure histories do not violate recommended acceptable limits even when the train passes through the station a t 65 kmlh without stopping.