What is the function of a "frog" in a switch?

The function of a "frog" in a switch is crucial for allowing train wheels to safely cross from one rail to another at a switch point. Specifically, a frog is a piece of track that provides a continuous path for the wheels as they transition between two diverging tracks. When a train approaches a switch, the frog guides the wheelsets of the train either straight ahead or to the diverging track, ensuring smooth and safe movement without encountering gaps or misalignments that could cause derailments.

This component is engineered to accommodate the wheel profile and the specific gauge of the track, facilitating seamless crossings. It plays a key role in maintaining track integrity and smooth train operations through junctions and sidings. The design of the frog allows trains to navigate complex track layouts efficiently, making it an essential element of railroad infrastructure.