Which term is a switch within interlocking limits controlled by the Block Operator or Train Dispatcher working in conjunction with interlocking signals and other interlocking appliances?

• A. Interlocking Switch
• B. Spring Switch
• C. Hand-Operated Switch
• D. Electric Lock Switch

Answer: (A)

Coordinating track switches with signals inside an interlocking is about ensuring a route is safely set only when all interlocking conditions are met. The switch that operates within these interlocking limits and is controlled by the Block Operator or Train Dispatcher through the interlocking machine, in concert with interlocking signals and other devices, is called the interlocking switch. This term highlights that the switch is part of the interlocking logic—its position and movement are secured by the interlocking to prevent conflicting movements.

Spring switches are a specific type of turnout with a spring mechanism to return to a default position, not the name for a switch governed by the interlocking system. Hand-operated switches are simply manually operated and may exist outside interlocking, or be controlled without the interlocking logic. Electric lock switches refer to switches that use an electric locking device, which is a hardware feature, but the proper term for a switch governed by the interlocking system is interlocking switch.