This video, shows the components of the ISE "Squealers" that I've been adding to the layout lately. They have a motion-detecting sensor between the ties and make a very realistic wheel flange sqealing noise whenever a car or engine triggers it. And when the train stops, the sound stops, just like a real train. I've had several of them in operation for several years now, and am installing 5 more soon. It really adds to the realism of operations. I've also had great experience with the staff of ISE, who are very responsive to any questions and issues.
The photo above is a rare view of inside the tunnel between the Everett Bayside yard and the Delta Wye. I'm planning to put a Squealer in there to give yardmasters a heads up that a train is coming their way inside the tunnel. The weights are on the track because I had to re-glue the track down after drilling the hole from underneath to install the sensor in. Oh, well...
