This paper describes a series of explosion experiments in inhomogeneous hydrogen air clouds in a standard 20' ISO container. Test parameter variations included nozzle configuration, jet direction, reservoir back pressure, time of ignition after release and degree of obstacles. The paper presents the experimental setup, resulting pressure records and high speed videos. The explosion pressures from the experiments without obstacles were in the range of 0.4 to 7 kPa. In the experiments with obstacles the gas exploded more violently producing pressures in order of 100 kPa.