Siren Installed in Portland Plant
(From Our Regular Correspondent)
The Northwest Steel Company, of Portland, Ore., has installed an electric Federal siren to be used as a fire whistle, the first of its type to be used in this locality. Sound from this siren will carry three-fourths of a mile, and can be augmented, if desired, to carry two miles, in either case depending upon wind, weather and surroundings. It is operated by a two horsepower electric motor, is 24 inches in length, 12 inches in diameter at the throat and weighs 200 pounds. In construction it is one cylinder inside a larger, each having 4×1 inch square slots cut through, which produce sound when revolved at 1,800 r. p. m. The siren does not necessarily produce the loudest sound, but gives a peculiar tone, graduating up and down the scale, making an effective alarm. It is operated by the use of a make-and-break knife switch from the compressor engine room. The number of the station sending in an alarm is indicated by reducing and augmenting the sound, allowing five seconds between notes.