Styrene mockup of the ice house testing location at Sudbury yard. Bits of green tape mark frogs in the yard that have had power feeders attached. We’ve been installing small electronic units called “Hex Frog Juicers” that can power and automatically change the polarity of up to 6 frogs. This and ensuring that every point rail has its own feeder has greatly reduced stalling in the yard due to dead spots on frogs and points.