The U.S. Bureau of Mines, as part of its research program for controlling underground mine explosions, conducted a series of single-entry tests in the experimental mine at the Lake Lynn Laboratory to evaluate the performance of triggered barriers against gas explosions. Results from the triggered barrier tests in a wide entry (6.1-M) showed that combinations of the dual-tube assembly near the mine roof were successful in suppressing gas explosions. In one installation, eight 1-m-long dual-tube units staggered perpendicular to the ribs, 18 to 36 m from the face, quenched the flame from a 12.2-M 10 pct methane-air zone. The flame, which would travel 61 m from the face without barriers, was suppressed within 38 m. The initial phase of this program is to optimize the water dispersion while maintaining accessibility to mining machinery, particularly in regards to mine roof clearance. The triggered barrier tests utilize a solar panel detector, which generates power from the flame radiation of the explosion to initiate the barriers.