One of the trip-whistles installed in the loops area of the NRX reactor at Chalk River. Each experimental loop had a separate whistle which was attached to an alarm panel. The alarm panel could trigger a compressed air flow to the whistle when a fault occurred and the whistle would sound (all 3 tones simultaneously) to alert operators that an experimental facility had exceeded some critical parameter, typically overpressure or overtemperature, and had been automatically shut down. In the present unit, which measures approximately 19 cm in length, the three whistle columns are 11, 9 and 8 cm in length.
