[en] A series of 48 intermediate-scale steam explosion experiments was recently completed. The purpose of the experiments was to investigate the efficiency of converting the thermal energy of a melt into mechanical work during a reasonably large steam explosion. The melts used were 1 to 27 kg quantities of an iron/alumina mixture. The melts were poured into an open tank of water. The primary parameters varied were water quantity, melt quantity, and water temperature. Spontaneous explosions occurred in most of the experiments with several experiments exhibiting multiple explosions. Some explosions were artificially triggered with no observed enhancement in efficiency. Pressurizations with peak amplitudes of 5 to 10 MPa and a few milliseconds duration were usually obtained near the tank walls. Higher amplitude pressure spikes of very short duration were sometimes seen on the pressure traces