The Siren Board

I can answer this one. A semaphore is a railroad signal with an arm and sometimes a light to indicate whether to stop (red), proceed with caution or prepare to stop at next signal (yellow) or clear signal, proceed at speed (green).

Photo is not mine.
http://farm1.static.flickr.com/21/31563 ... a5.jpg?v=0

http://farm4.static.flickr.com/3219/272 ... 19.jpg?v=0

It works just like a standard block signal does, just that the arm moves along with the glass for the light. There are either two or three glasses on the back of a semaphore signal arm. Red/Green, Red/Yellow/Green, or Yellow/Green.

red40stang, back me up if I'm wrong on any of this..lol[/url]

These semaphores were photographed in 2007 near Creswell, Oregon, and were only recently replaced with modern three-light signals. There are still a handful of them in use on old logging lines. Some of them were visible from I-5 and could be seen illuminated at night. A motor in the base pulls a cable to orient the semaphore while a lamp shines through the appropriate colored lens.

JasonC wrote:Yep, it's definitely a semaphore Looks like the tracks were abandoned quite a few years ago, but they are still mapped on Google Maps. A lot of old depots kept their semaphores for historical purposes. Don't feel bad though, a lot of common things are mistaken for sirens all the time.

Yeah, like when i mistook a semaphore for a 2001 >_>