The results of a model study of the diffraction of transients from blasting caps over barriers are reported. A prediction technique based on Oberhettinger time domain notation was developed [J. Res. Natl. Bur. Stand.61,5 (1957)]. The results of this calculation are compared to the data. Finite wave effects were incorporated into the prediction and were shown to be small for the geometries and charge size employed in the model study. The finite wave effects on diffraction of transient may be important for shorter duration pulses such asNwave from sparks.