chicken switch
n.— «All anyone knew for sure was that the nuclear-powered attack submarine had slammed head-on into something solid and very large, and that it had to get to the surface fast. In the control room, a senior enlisted man shoved the “chicken switches,” blowing high-pressure air through the ballast tanks to force the vessel upward. Usually, the submarine would respond at once.» —“Adrift 500 Feet Under the Sea, a Minute Was an Eternity” by Christopher Drew New York Times May 18, 2005. (source: Double-Tongued Dictionary)