Shock wave speeds are often measured by comparing arrival times at the tips of electrical shorting pins in a hexagonal array over two elevations (called up and down). In the conventional arrangement, the center pin is solely responsible for measuring the curvature of the wave front. Without this datum the shock speed cannot be precisely determined. In some experiments this pin fails frequently enough to be a problem. We report a simple rearrangement between up and down designated pins which eliminates the critical reliance on a single pin. ©1995 American Institute of Physics.