Which term refers to a switch that must be properly aligned prior to making a trailing movement?

• A. Trailable Switch
• B. Normal Switch Position
• C. Reverse Switch Position
• D. Non-Trailable Switch

Answer: (D)

The concept being tested is whether a switch can be safely traversed by a trailing movement only if its position is fixed before that movement starts. A non-trailable switch is the one that must be properly aligned prior to any trailing movement because you cannot adjust it from the trailing end once the train is moving. In other words, you’re required to set the switch correctly ahead of time to avoid derailment or misrouting as the trailing portion passes.

If a switch were trailable, it would be designed to be adjusted or influenced by the trailing movement, which would not require pre-alignment in the same way. The other terms describe positions or states of the switch rather than the operational capability regarding trailing movements, so they don’t fit the constraint described in the question.