2001
The Federal Signal 2001 Series is a line of outdoor warning sirens produced by Federal Signal. Variations include the 2001SRN, 2001SRNB, and the 2001-130.
2001SRN
The 2001SRN siren was produced from 1990 to ? and was a design overhaul from it's predecessor, the Thunderbolt Siren. This model is identifiable from its successors by the large, rectangular rotator box design borrowed from the Thunderbolt as well as the "2001DC" label on the rotator. This series came in two forms, the "Roundback" and the "Squareback" (pertaining to the shape of the chopper housing), although not officially distinguished as so by Federal Signal. Roundback models are notably more rare than the Squareback variant, with a few of the known Roundback sirens being located in Fostoria, Ohio; Romeoville, Illinois, Southaven, Mississippi; and Prior Lake, Minnesota. The only difference with the Squareback variant is the shape of the chopper housing being square, as the nickname suggests.
2001SRNB
The 2001SRNB was the second generation of Federal Signal's 2001 series. The design is similar to its predecessor, the 2001SRN, with the most notable change being a refined stator design, increasing the sound output to 128 dBc at 100 feet. Secondly, a new square gear-driven rotator replaced the belt-driven rotator originally inherited from the Thunderbolt.
2001-130
The 2001-130 is the latest version of Federal Signal's 2001 Series. The 2001-130 model began production in 2006 with production continuing today. They made changes from the 2001SRNB by increasing the output to 130 dBc (hence the 2001-130 name) and making the square back of the siren taller.