What type of signal is specifically used for controlling the movements through an interlocking?

The type of signal specifically designed for controlling the movements through an interlocking is an interlocking signal. Interlocking signals are vital in ensuring that train movements are regulated safely within complex track configurations where routes intersect and diverge. These signals coordinate the actions of switches and locking mechanisms that prevent conflicting movements, which could lead to accidents.

Interlocking signals provide the necessary indications for train operators, signaling them when it's safe to proceed and when to stop based on operational requirements and the status of track conditions. The use of interlocking signals is critical in maintaining the integrity of train operations within busy or complex rail networks, as they facilitate the smooth transition of trains through areas where multiple tracks meet and overlap.

Other signal types such as controlled signals, distant signals, and block limit signals serve different functions within the broader signaling system, but none are specifically dedicated to managing movements through interlocking setups in the same way that interlocking signals are.