Cast-iron sleepers
Cast-iron sleepers are a type of sleeper used in railway tracks. They are made by casting molten iron into a mold to form the desired shape. These sleepers have been widely used in the past but are now less common due to their higher cost and lower durability compared to other types of sleepers.

Cast-iron sleepers are typically used in areas where wooden or concrete sleepers are not suitable, such as in areas with heavy loads or in highly corrosive environments. They are also used in some heritage or historic railway lines for their aesthetic appeal.

Fixtures in chairs
In railway tracks, the rail chairs or rail fastenings are used to hold the rails in place and provide stability. These chairs can be made of various materials such as wood, steel, or concrete, depending on the type of sleeper being used.

Cast-iron sleepers and chairs
In the case of cast-iron sleepers, the chairs used as fixtures are also made of cast iron. The chairs are cast along with the sleepers during the manufacturing process. This means that the chairs are formed as an integral part of the sleeper itself, rather than being separate components that are attached later.

The advantage of casting the chairs with the sleepers is that it provides a stronger and more secure connection between the chairs and the sleepers. It eliminates the need for additional fasteners or connectors, reducing the risk of loosening or detachment over time.

Additionally, casting the chairs with the sleepers allows for better alignment and positioning of the chairs, ensuring the rails are properly supported and aligned. It also helps in maintaining the gauge (distance between the rails) and overall stability of the track.

Overall, casting the chairs with the cast-iron sleepers provides a more robust and durable track system, especially in areas where the track is subjected to heavy loads or harsh environmental conditions. However, due to the higher cost and limited availability of cast-iron sleepers, they are not commonly used in modern railway track construction.