Collision avoidance circuit for layout with a WYE "stub" yard
My layout has a WYE "stub" yard track as shown. To avoid the potential for a collision between trains on the main outer loop and trains exiting from the "stub" yard track a "Collision Avoidance Circuit" was installed.
This lockout circuit is used to prevent collisions or derailments due to trains entering from the yard track to the main track via the WYE.
When the turnout route is set to “Bypass the WYE” then yard track is automatically set to an “unpowered” condition. As a result no engine is permitted to operate in the yard track and therefore cannot enter the "main line" via the WYE.
The lockout circuit is controlled by the position of the main turnouts. When the turnouts are set to “Bypass” the WYE then the yard track automatically becomes nonpowered.