What are the components of a rail turnout?

A rail turnout, also known as a railroad switch or point, is a crucial component of railway infrastructure that allows trains to transition from one track to another. It consists of several components working together to enable safe and efficient rail operations. Here are the key components of a rail turnout:

1.     Switch Rails: Switch rails are the movable rails that guide the train from one track to another. They are typically composed of two parts: the stock rail and the switch rail. The stock rail is the main rail of the track, while the switch rail is the movable rail that can be aligned with either the stock rail or the frog.

2.     Frog: The frog is the central component of a rail turnout and is located where the switch rails and the stock rail intersect. It forms a V-shaped structure that allows the train's wheels to move from one track to another smoothly. The frog has flange ways that accommodate the wheels and keep them on the correct path during the switch.

3.     Point Machine: The point machine, also called a switch machine or turnout motor, is a device used to control the movement of the switch rails. It is typically electrically or mechanically operated and is responsible for aligning the switch rails with the desired track. The point machine ensures that the switch rails are in the correct position to guide the train in the intended direction.

4.     Slide Chairs: Slide chairs are fixed to the sleepers (ties) and support the switch and stock rails. They allow the switch rails to move laterally during the switching process. Slide chairs are designed to withstand the forces exerted by passing trains and ensure the smooth movement of the switch rails.

5.     Stock Rail Chairs: Stock rail chairs, also known as base plates, are used to secure the stock rail to the sleepers. They provide stability to the stock rail and maintain its alignment with the rest of the track. Stock rail chairs are typically made of metal and are fastened to the sleepers using bolts.

6.     Guard Rails: Guard rails, also called check rails or closure rails, are additional rails placed adjacent to the frog. They serve to guide the train wheels through the frog and prevent derailment. Guard rails ensure that the wheels maintain proper alignment as they pass through the frog and switch from one track to another.

7.     Switch Stand: The switch stand is a mechanical device used to manually operate the rail turnout. It consists of a lever and associated mechanism that controls the position of the switch rails. The switch stand is commonly used in situations where there is no electrical or motorized control system available.

8.     Connecting Rods: Connecting rods are used to transmit the motion from the point machine or switch stand to the switch rails. They connect the operating mechanism to the switch rails and ensure that the switch rails move in unison. Connecting rods are designed to withstand the forces and stresses generated during switching operations.

9.     Heel Blocks: Heel blocks are devices located at the ends of the switch rails near the frog. They prevent excessive lateral movement of the switch rails and maintain the proper alignment with the frog. Heel blocks play a crucial role in ensuring smooth and reliable train movement through the rail turnout.

10.  Track Circuits: Track circuits are electrical systems installed in rail turnouts to detect the presence of trains. They consist of insulated sections of the track that can detect the electrical continuity of a passing train. Track circuits provide important information about train occupancy and play a vital role in signaling and train control systems.

These components work together to enable trains to switch from one track to another smoothly and safely. Rail turnouts are essential for efficient railway operations, allowing trains to navigate complex railway networks, change routes, and facilitate the movement of trains between different tracks.