Track indicators?

[jagged ben]

What are these track indicators that Steve mentions and how did they work, and what colors were the lights and stuff?

http://www.railpictures.net/viewphoto.php?id=436676

Been wondering about them for a while.

[DKS]

Track indicators are signals for speeders. They are fast disappearing because they're no longer needed due to changes in rules governing how speeders can operate.

[C855B]

The speeder signals in that photo housed miniature lower-quadrant semaphores, and were unlit. They were basically voltmeters measuring the power across the track circuit - when voltage went to zero the "semaphore" moved to the stop indication. I strongly suspect those are gone now with the very recent signal replacement project in the Tehachapis.

Santa Fe used a similar housing for a single bare bulb that glowed rather faintly - on when the block was clear, off when a train was in the block. Pennsy had a slightly different case design with a rotating disk for an indicator, showing three vertical black dots when clear and horizontal dots when occupied, similar to a PL signal. I think others also used this type.

[jagged ben]

Thanks.  I guess from a modeling point of view there's not much to them except as a trackside detail.  I was wondering if they fit into the signal system somehow but I guess not.

[cv_acr]

Thanks.  I guess from a modeling point of view there's not much to them except as a trackside detail.  I was wondering if they fit into the signal system somehow but I guess not.

Well sorta. They're tied into the track wiring to show block occupancy for speeders and maintenance crews, or the trainman who's down on the ground to throw the switch. But train crews (on a moving train) can't see them. (They're unlit and also arranged perpendicular to the tracks.)

[jagged ben]

Yeah, what I meant was that there's no lights to model and it wouldn't affect train operators on our club layout.   

(Now if someone could make an operating N scale speeder...)