What does a switch machine operate mechanically?

The function of a switch machine is specifically to control the movement of switch points or a derail on a railway track. The switch machine mechanically adjusts the position of the switch points, which are the movable sections of track that allow trains to switch from one track to another. This is crucial for directing trains safely and efficiently along the rail network. A switch machine can be electrically or manually operated, ensuring that trains can change tracks according to the required routing.

The other choices do not pertain directly to the mechanical operation of a switch machine. Track signals relate to signaling systems that manage train movements and ensure safety by conveying information to train operators. Train brakes are part of the train's control systems designed to slow down or stop the train. Network communications involve systems that allow for various forms of communication across the railway infrastructure, which is distinct from the mechanical operations of a switch machine.