The paper addresses the question of the effect of turbulence on the development of gas explosions by discussing experimental results obtained in a 1.35-m3 spherical vessel. The turbulence is introduced by flow injection into the test volume from a high-pressure source. The evolution of the transient turbulence field is characterized through time-resolved velocity measurements made with a bi-directional probe specifically developed for the application. Data are presented for one (9.5%) methane-air and two (4.0 and 4.8%) propane-air mixtures for turbulence intensities up to 13 m/s, corresponding to an estimated turbulence Reynolds number of 41,900 based on the integral length scale. Values of equivalent turbulent burning velocity calculated from the initial rise of the pressure traces are similar for the three tested mixtures. Maximum rate of pressure rise data, on the other hand, show increasing reactivities of the mixtures in the order 9.5% CH4 to 4.0% and 4.8% C3H8. Furthermore, for each mixture, the maximum rate of pressure rise increases linearly with turbulence intensity. No evidence of quenching is apparent in the data, even though estimated values for the Karlovitz stretch factor indicate, that quenching conditions should have been approached at the high end of the range of turbulence tested.