These are single-bladed switches installed on ascending grades to protect against rollbacks. If a car breaks loose and rolls backward down the hill, the points force the wheels off the rails and onto the ballast. This controlled derailment stops the runaway before it can gain enough momentum to cause a catastrophic collision with following traffic.
Heard on the job
Make sure the catch points are lined for the ditch before you cut away from those bad order cars.
Also heard as
- split-point derail