Experimental data are presented for verifying the computer program for computing propellant oscillation modes and frequencies for tanks of any shape, fill level, or orientation. The experimental apparatus including the tank, support and excitation system, and instrumentation is described along with the procedures. Results showing slosh forces and moments are tabulated for different fill heights. It was found that for the vertical tank excited along the long axis, the frequencies of the higher modes are significantly higher than with the tank tilted. Little difference was noted for excitation along the short axis