Sleight of Hand Times Three
The first of three main hat tricks performed on the Squirrel Valley is the logging switchbacks trick. This involves having a full log train come down the mountain via the logging switchbacks and an empty one go up the mountain by use of these same switchbacks. But since I don't really load logs on the trains while up the mountain or dump the logs at the log mill's log dump at the base of the mountain, I must have a method of getting full trains up the mountain and empty trains down the mountain. The solution is a logging elevator built into the mountain itself. Drive a train in (an extra bonus here: no elevator music!), turn on the motor, wait for the indicator light to light up, turn off the motor, and drive a train out. An under-the-mountain siding/waiting track and a trio of Circuitron Opto-Sensors are my not-so-leggy assistants in this hat trick. They let me know when a train is on a hidden siding or fully into the under-the-mountain elevator (entered by tunnel portals at the top of the mountain and through a log train building—whatever that is—at the base of the mountain). These sensors require in-mountain lights in order to operate when cars shade the light. The sensors light indicator lights (by use of a Circuitron DT-4) on the profile board-based control panel when trains are present. It's a bit unusual for trains to have to go through tunnel portals on the way up to (and down from) being loaded with logs, but this is a necessary part of the trick. See fig. 3.
The second hat trick is the lead mine operation. Full cars are hauled from mine to mill and empty cars are hauled from mill to mine—and that's all you see. Instead of two separate locos, like with the logging operation, I chose to have only one. It scurries around under the mountain, sneaking out to grab the fulls at the mill and pull them around under the mountain until they are uncoupled at the loading tipple outside the mine. Then it grabs the empties that it had previously hauled to the mine and hauls them through the mountain to the mill; it uncouples them in the ore unloading area. Then it begins the whole sequence all over again. See fig. 4.